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"How to" OEM Focus ST170 ecu with Pats info.
big_wasa - 13/4/14 at 07:01 PM

"How to" OEM Focus ST170 ecu with Pats info.


As this is locost builders there are some people left that love to tinker and make things.
This is to give those people that are interested in running an ST170 engine on a budget the basic wiring information. months of work this.

The key to using the ecu is the Pat's immobilizer. You must get atleast one key with chip that is matched to the ecu.

Ford 104 pin Focus ST170 2003 ď 3NFAĒ Pcm plug.

Missing numbers have no connection and are not used on the Pcm.

Pin number -- colour -- function.

03 white/red--IMRC pin4
09 white/black--Barometric sensor pin 3
12 black/white ĖIMRC pin 3
13 orange/black--DLC pin 13 modal program.
15 blue/black-- DLC pin 10 scp-.
16 grey/orange-- DLC pin2 scp+.
17 black/white Ė high speed fan.
19 grey/orange -- Pats TX signal.
20 black/blue -- Injector 3 switched earth.
21 white/red -- crankshaft position sensor +.
22 brown/rd --crankshaft position sensor -.
24 black/yellow -- earth.
25 black/red -- earth.
26 black/orange Ė coil pin 1.
27 black/red -- start inhibit relay.
28 white/violet Ė telemetric.
31 black/yellow -- Power steering pressure switch.
32 brown/yellowóknock sensor pin 1.
35 white/redó HSO2 1 pin 4.
36 brown/blue -- MAF pin 4.
37 white/greenófuel rail pressure switch pin 1.
38 white -- coolant temp sensor pin 1.
39 white violet -- Air temp in MAF pin1.
40 green/black -- fuel pump driver pin 7.
41 green/yellow -- A/C clutch pressure switch.
42 black/orange -- PATS Led.
43 white/blue Ė- Trip computer.
45 black/redóvvt solenoid pin 2.
46 black/greenóEngine run relay
49 blue/redóDLC pin 14 can-.
50 grey/redóDLC pin 6 can+.
51 black/yellow -- earth.
52 black/green -- coil pin 3.
53 white/green -- Pats RX signal.
54 black/white -- fuel pump driver pin 1.
55 red-- KAM perm live.
56 black/blueóevap pin 2.
57 white/blackóknock sensor pin 2.
58 white/blue -- Vehicle speed Sensor pin 2.
59 grey Ė Alternator pin 1.
60 white -- HO2S 1 signal
64 white --clutch switch.
68 black/blue Ė engine cooling fan.
69 black/yellow -- Ac wot relay
70 black/white -- injector 1 pin2.
71 green/yellow -- switched 12v from power relay.
72 blueóalternator pin 2.
76 white/violet -- Cam position sensor pin 1.
77 black/yellow -- earth.
83 green/yellow -- idle air control valve pin 2.
85 brown/white -- camshaft position sensor pin 2.
86 white/red -- Ac high pressure switch.
88 white/blue -- MAF pin 5..
89 white -- throttle position sensor pin 2.
90 yellow -- 5v Voltage Reference (5v out from ecu)
91 brown -- sensor common brown
93 black/yellow -- HO2S 1 heater control.
95 black/orange -- injector 4 pin 2.
96 black/yellow -- injector 2 pin 2.
97 green/yellow -- switched 12v.
100 black/blue Ė HO2S 2 pin 2.
103 black/yellow -- earth.

The Immobilizer.

The picture below shows the transceiver or aerial. This is found behind the steering cowl. The ring sitís around the ignition switch and is held to the steering column with one screw.

This is the wiring plug.

It needs cutting from the car with as much wire as can be pulled free.

Retaining clip shown at the bottom.

There are four pins, They may be colour coded as above or they may be all black as shown in the photo. This depends on the age of the donor.

Pats indicator. This is the led that is usually found in the clock. Its job is to show you the status of the immobilizer. Fordís Passive Anti- Theft- System ( PATS )

Just one Pin from the ecu plug, No 42 (black/blue). This is a switched earth. Take one Led, colour of your choice. You need one that is pre wired with a resistor. This is mounted in your dash. The negative or black wire is connected to pin 42 of the ecu plug and the red or positive wire is connected to the permanent live.

ďDLCĒ Diagnostic link connector.

The obd2 plug is found under the steering wheel. The plastic body should be unclipped from its holder and cut from the Mondeo with as much wire as can be pulled free.
The tape covering the wires can be removed.

You will be left with This.

The pinís are numbered as below.

Not all pins are used. you have power and earth as well as can bus ect.





Cam sensor.

Fuel pressure sensor on the end of the fuel rail.

Throttle position sensor.

Pre cat O2 sensor.

Post cat O2 sensor.

Purge valve.

Idle control valve.

Fuel pump control module.

Knock sensor.

Inlet manifold runner control module.

Mass air flow meter.

Hope this helps any one wanting to run an St170 without spending shed loads. Its no harder than making a loom for a MS ecu just more of it. There is no mapping and the ecu can be had for a few quid. They are called an St170 as they are meant to be 170 ps at the fly'. NOT all are but by no means are they all dogs. The key to keeping them on song is to make sure all sensors and actuators are tickerty boo.

[Edited on 13/4/14 by big_wasa]

ceebmoj - 13/4/14 at 07:23 PM

Thank you for the information great post

coozer - 13/4/14 at 07:29 PM

Great post.

Just to add the pats receiver can also be found on any X type Jaguar.

big_wasa - 13/4/14 at 07:35 PM

More plugs for you to eliminate.

Speed sensor found in the gear box.

Reverse switch found in the gearbox.

Inertia switch found in the fuel pump feed.


Ac clutch (ecu controlled )

Ac high pressure switch.

You will se an ecu pin for the high speed fan. This is for the Ac. The coolant fan is done the old school way on the St170 with a switch in the rad. This is the same M22x1.5 as the the polo rad so the switch is a direct transplant and will work at the designed temp.

I will add more as I remember and as I go but I wont have time to do a "wiring diagram" I've tried and it just looks like spaghetti.


big_wasa - 13/4/14 at 07:37 PM

Originally posted by coozer
Great post.

Just to add the pats receiver can also be found on any X type Jaguar.

That's because it uses the ford platform, S type is different.

coozer - 13/4/14 at 08:37 PM

Originally posted by big_wasa
Originally posted by coozer
Great post.

Just to add the pats receiver can also be found on any X type Jaguar.

That's because it uses the ford platform, S type is different.

Its because the Mondeo and X type use the same steering column (as well as most other parts) and Ford passed it onto the Focus at the same time.

Funny thing is the column went on the mondeo until 2007 when Ford moved onto the new platform, that killed the X type off BUT the factory I worked in still make the column now for the DB9...

garybee - 14/4/14 at 11:58 AM

That is absolutely fantastic, must have been quite a job.

One quick question (and sorry if I've missed it and the answer's there), what is the orientation of the pictures? Are they looking towards the loom from the component or towards the component from the loom?

Many thanks


big_wasa - 17/4/14 at 05:35 PM

looking at the pins I think but the plugs do have numbers next to the pins.

garybee - 17/4/14 at 07:08 PM

It'll be easy enough to work out with the loom in your hand anyway, as the wire colours are there.

Your-nme - 23/4/15 at 06:45 PM

Hi Big_wasa,

I saw in another Post that you where wondering if somebody was trying to get an st170 running with the original ecu. My answer is Yes. But i'm strugling a bit. The Pats is working, got no spark and fuel pump shuts of after 3 sec but looks like this is not due to the pressure sensor.

Any suggestions?



big_wasa - 23/4/15 at 07:06 PM

Hi, nice to see some one having ago.

So you have the pats led connected ? You turn the ignition on and the light stops flashing and goes solid on for a short time ? The pump then runs for a few seconds ? When you crank the engine what does the light do ?

It won't fire the coil if there is no crank or cam signal.

Connect an obd2 device and view the live data. Is the ecu seeing the engine turn over ?

Your-nme - 23/4/15 at 07:21 PM

So you have the pats led connected ? Yes
You turn the ignition on and the light stops flashing and goes solid on for a short time ? Yes
The pump then runs for a few seconds ? Yes
When you crank the engine what does the light do ? The led turns of and stays off

Have the odb2 connected. Can see the live data as temp and throttle position. But when i crank the engine is see no changes on the screen.

big_wasa - 23/4/15 at 07:25 PM

It should read an rpm so my guess is the ecu is not seeing the crank or cam sensor. Check the wiring and polarity. With no signal it won't fire the coil and it will cut the fuel pump.

big_wasa - 23/4/15 at 07:33 PM

Is there any posability the engine had an automatic gearbox ? I've never seen an automatic St but I don't pretend to know everything. What flywheel do you have ? Is there any chance the cps housing has been swaped for one from an auto ?

Your-nme - 23/4/15 at 07:59 PM

Cam sensor is connected correct.
I kept the original wiring of the st170.
It was a manual gearbox. I used the flywheel that was on the previous engine. Cvh 1,6 with a t9 gearbox.
The sensor that is pointed to the flywheel. Can this be the problem? Because the original flywheel of the st170 has a pattern for the sensor. The cvh doesn't have it.

A few wires that i could not find a logic point to connect to:
27 start inhibit relay
17 high speed fan
69 engine cooling fan
91 common brown

But don't think they influance the working of the engine. I think

[Edited on 23/4/15 by Your-nme]

big_wasa - 23/4/15 at 08:24 PM

Yes that's your problem. The only cvh flywheel that will work is the very late 90 spec efi engines like the rs turbo and xr3i. Get your self a 1.8 zetec flywheel.

Re the wiring. Starter inhibit relay. The ecu stops the engine being cranked over while being immobilised. You can live with out that when it's wired properly. You can leave the fan wires most are for the ac. You must switch the fan on in another way ie switch in the rad.

The sensor common is VERY important. This is the common earth to most sensors. NOT A CHASSIS EARTH.

Your-nme - 23/4/15 at 08:40 PM


So the zetec 1.8 flywheel also has the pattern as the st170?
Just to confirm because I'm a hobby electrician. The common sensor wire. I have to connect it to the negative of the battery.

So will try to get an flywheel of a zetec 1.8.

big_wasa - 23/4/15 at 08:54 PM

So the zetec 1.8 flywheel also has the pattern as the st170?

YES 36-1 you could also use a trigger wheel on the front crank pulley. It's not a bolt on item.

Just to confirm because I'm a hobby electrician. The common sensor wire. I have to connect it to the negative of the battery.

NO NO NO NO YOU WILL POP THE ECU. Ecu to the sensors that need it ONLY ! Black and yellow trace, Black and red trace are chassis earth.

Your-nme - 24/4/15 at 12:39 PM

Maybe a stupid question.
I have found a 1.6 / 2.0 zetec flywheel with all parts. Assuming this will do the trick.
Or is there a big difference between zetec 1.8 and the mentioned one.
Can't see any big difference on the pictures.

big_wasa - 24/4/15 at 03:56 PM

There are two types of zetec. The zetec E and the zetec SE.

You can indeed get a 1.6 zetec E which is a silver top engine. It's the same flywheel as the 1.8 silver top or black top.

But when the engines went from silver top to black top ford dropped the 1.6 zetec E and replaced it with the all alloy zetec SE also known as the sigma.

The 2.0 clutch is 240mm and the 1.8 / 1.6 is 220mm.

So yes an early 1.6 fly will fit but a later 1.6 fly will not.

Keep us posted and I'd didn't start if there was no video

Your-nme - 24/4/15 at 04:58 PM

This is the parts I am trying to purchase.


Have requested the diameter of the frictionplate.

my project



big_wasa - 24/4/15 at 08:02 PM

Shame you're not local. I have a flywheel that should work that I keep tripping over. Its a very rare sierra cfi. Its already rwd to t9 so no need for the thicker thrust bearing.

Your-nme - 24/4/15 at 08:13 PM

I will be in the uk on the 15 of may. But that will be near birmingham. Have purchased a new body for my westfield.
Am driving via the eurotunnel so spalding is a bit in the wrong direction.

Your-nme - 17/5/15 at 07:28 PM

I installed a new 2.0 zetec flywheel. Finally its running.
Only for a few seconds but that is because I still have IMRC not working (That is what I think). Only have connected the wires as you mention. But struggling with the ground and switched ground leads.

First will make the exhaust with both sensors. i hope it will work when I will put these behind each other.

big_wasa - 17/5/15 at 07:44 PM

It will run with out the irmc but not at its potential, it will also give a fault code.

But if it fires you are getting there.

If a sensor has a brown wire it goes back to the ecu. Its a sensor ground It's not a chassis ground.

Your-nme - 24/5/15 at 09:03 PM

So I finally have it running. Stil only up to 20 sec because it is still without coolant.
When with coolant I will hang the Odb2 and see if there are any Faillure messages.
Keep you informed.

big_wasa - 17/6/15 at 08:39 PM

Great to see progress at least I know some one tried it.

Your-nme - 22/6/15 at 07:47 PM

Small update: the engine is running well.
Have two questions and hope you can help.
1. The hose thet is inbetween the air intake and the airchamber below the cilinders (you had closed this part). I'm having a high vacuum that the hose closes itself. Is that ok?
2. Trying to connect a digidash2 lite. Have to connet the tacho to the ecu. Read that pin 48 is for the tacho in many forums but that is only for the zetec ecu. Is there a pin on the st170 that does the trick? Have been searching the web but no succes until now.

big_wasa - 22/6/15 at 08:01 PM

1) got a picture ?

2) it's all done by can bus on the St will your dash read can bus ? You could take a trigger from the coil but it's wasted spark so your dash will need to half it.

Your-nme - 22/6/15 at 08:53 PM

1) Hose vacuum
Hose vacuum

2) Ok. The digidash2 does not support canbus. So will have to get it from the ignitioncoil I guess.

big_wasa - 22/6/15 at 09:19 PM

That's for the evaporation canister purge valve.

It's a charcoal canister that collects the fuel vapours from the tank and the ecu decides when to burn them off.

You won't have it so blank it off. The main reason for poor running will be an air leak.

Have you blanked of the brake servo port ?

big_wasa - 22/6/15 at 09:30 PM

The other one is the block breather. No idea why that would be collapsing.

Your-nme - 25/6/15 at 09:25 PM

Question, which cable of the ecu should have permanent 12v. At the moment i'm switching all power on with the ignition switch. So no blinking of the led before I turn the key.
Other thing I can't understand. When i drive and keep the engine at a continious rpm it stutters. When i accelerate absolutely no problem. During driving when i lift the gaspedal at 3000rpm and push the clutch to get the engine back to Idle it shuts down.
Tried to find why the block breader hose is collapsing but still no clue.

Found this site

I will firstly start with some new ht leads.
Any suggestions that could help?

big_wasa - 27/6/15 at 11:16 AM

On page one mate pin 55, wire will be orange or red. Referred to as KAM keep alive memory. The ecu learns some perimeters you will be resetting this every time you start the engine with out.

View as much live data as you can via the obd2 port. If all sensors are giving sensible values most faulty running issues are down to air leaks. One I looked at last week would not idle until I asked if the brake servo and other inlet ports had been blocked of. They hadn't so easy sorted.

I will check but I think the clutch switch may need earthing.

Keep going your nearly there.

Your-nme - 27/6/15 at 07:57 PM

Had the 55 pin already connected to the battery. But see no blinking led. Then saw that the led also needed 12v ;o)

Have closed the the blockbreeder and the connections for the evaporation canister purge valve.
The brake servo is also closed but don't know if it is 100% shut. Will check on this.

I don't think I have a clutch switch.

Will keep going on.

Yesterday have done several a 0 to 60. It is dramatic. Took 8 sec. I think i'm missing a few horsepowers.

[Edited on 27/6/15 by Your-nme]

Your-nme - 29/6/15 at 06:02 PM

A little step forward.
Getting p1380 faillure code.
According to The web this is p1380 Variable Cam Timing Solenoid 'A' Circuit Condition.
Could this have something to do with the new cambelt I have installed? Have used the ford tool for this.

Have also installed an mil eliminator in the second O2 sensor.

big_wasa - 29/6/15 at 06:12 PM

That code suggests the vvt valve is doing nothing.

Check you have 12v one side and a good connection to ecu pin 45 the other.

[Edited on 29/6/15 by big_wasa]

Your-nme - 29/6/15 at 06:37 PM

Have got 12V and the other one is connected to pin45.
Just have seen that the imrc is pulling the lever back when starting but drops it within 2 sec. Im thinking that I still have a vacuum problem.

Getting p1380 and p1518
Only the p1518 disapeers after a few min.

[Edited on 29/6/15 by Your-nme]

rs moggy - 30/6/15 at 10:14 AM

hi all i have put the st170 lump in my mk3 escort was running it on a rs1800 efi inlet and a ford DEEP ecu but it was over fulling and no vvt working i now have put the st inlet on with some mods as it was a pane to fit but now it is in i have cut the full loom rite down but is a bit to big to get under my bonnet lol i cud do with a bit of help i need to get rid of the small fuse box but it wont run without it and the clocks but its hard for me to understand the links his is wot i have got it down to at the min it is grate work you have dun with out yore info i wouldnt have got this far so thanks

big_wasa - 30/6/15 at 07:16 PM

Hi, great to see people using the info for projects instead of chucking a credit card at it.

I am no teacher so it is a guide with the important bits rather than a total a connects to b.

If I can be of any help then give me a shout but I can't take on any loom jobs at the moment as I have to much on.

Yours should be easier than most as its fwd to start with.

Cheers wasa

rs moggy - 2/7/15 at 11:23 AM

hi waza its all dun and in the loom is still a bit big but all is good thanks for yore info and work you have dun grate to c ppl doing good jobs i have one small prob my IMRC plug do i wire it strate to the ecu ? imrc pin 4 to 03 ecu port white-red pin 3 to ecu pin 12 black-white got that part but dont no the rest can you let me no please have a look at my pics and thanks agen moggy

big_wasa - 2/7/15 at 03:51 PM

Hi, I cut the looms up and make them fit what it's going in so every thing is direct to the ecu with no sub looms.

So yes you have two pins to the ecu I think you have two chassis earths from memory and a switch 12v supply. In the donor it's one of the few plugs that's on the fuse box loom.

This is the project thread for the St

Love the escorts, I've had a mk3 3i 2x mk4 3i's and a mk4 3i cab with a knackered rst lump.


rs moggy - 3/7/15 at 07:43 AM

thanks for the info mate il let you no how i get on thanks

rs moggy - 4/7/15 at 04:21 PM

vacuum problem !!!! hi all i had the same its a week breather hose get some hard pipe as if you drive it it will smoke its titis off and bugger up ya seals up!!!!! ok i put hard plastic pipe in side it on the bend and job dun hope this helps ok mate

Your-nme - 5/7/15 at 07:51 AM

The camshaft position sensor: i've it connected to pin 76 and 85 of the ECU. But get no voltage on those pins. Am assuming that this is possibly my problem. Can anyone give me feedback on this?

big_wasa - 5/7/15 at 07:58 AM

No you won't see anything on that or the crank with out an oscilloscope.

[Edited on 5/7/15 by big_wasa]

big_wasa - 5/7/15 at 08:44 AM

From what I under stand you have taken the ecu loom along with the injector loom and the gearbox loom from the car with out the fuse box loom ?

So the wiring loom is un cut and unmodified ?

One thing to note is there is a separate earth from the ecu. This should not be earthed to the same point as the the other earths to avoid feed back.

You have just provided the relevant earths lives and you would need things that are out side the loom such as Pats aerial+led , Imrc, fuel pump driver ?

You have the obd2 connected and it is showing changing values for all the sensors ? One that will show no reading is the fuel pressure sensor on the fuel rail.

So when its running you are seeing an rpm, tps %, Ho1 Ho2 (after closed loom ) Maf

Crank and Cam are polarity sensitive but if the loom is uncut you cant have them wrong ?

76 white/violet -- Cam position sensor pin 1.
85 brown/white -- camshaft position sensor pin 2.

There is a yellow wire on the tps and the fuel sensor check you have 5v on both.

Idle control valves have been known to seize make sure you can move the plunger.

Upload some pictures to your archive.
It cant be much, you are further on than most.
I am out today but if you want to go through it I will be on here tonight

Your-nme - 5/7/15 at 09:16 PM

the ecu loom along with the injector loom and the gearbox loom: Yes those are uncut. Have used parts of the fusebox loom but totally modified it.

Pats aerial+led , Imrc, fuel pump driver: These have a Frame earth.

obd2 connected and it is showing changing values for all the sensors:
Yes, picture is of screenprint on hot engine

readout on hot engine
readout on hot engine

Crank and Cam are polarity sensitive but if the loom is uncut you cant have them wrong: Wright, have connected the correct colours to each other, so assume that ecu coloured wire and the uncut injector loom are the same. But have checked it with the beeper function on my multimeter.

other thing is that your connector picture does not correspond with my connector. So cannot confirm which of both is pin 1.
And this is the same with the connector of the IMRC. So have based the connections according to:
imrc connection
imrc connection

I had mixed pin 1 and 3 on the connector of the IMRC.
Only on startup the IMRC is pulling to shortrun mode. After approx 1 min it shuts off and goes back to the longrun postion (so car shut down position).
Have opened the IMRC according to the youtube movies. Cleaned the contact and it was not required to modify the spring attachment on the shaft.

Have got 5v on the tps and the fuel sensor.

Idle control valves, are fully functional.

Still have the P1380

And after a testrun I also got the P0720 missing speedo.

big_wasa - 14/7/15 at 07:08 PM

Ive been asked a couple of times about the imrc plug wiring that I missed from the original post. Due to the plug being fairly unique to just a few models there is little info on the net so I had to find one and trace it back as I could not find my original notes.

The plug has odd numbering.

1)green/white 12v.
2)black/white chassis earth.
3)black/white ecu pin 12.
4)white/red ecu pin 3.
5)black/blue chassis earth.
6)no connection.

Hope this helps

rs moggy - 14/7/15 at 07:25 PM

grate thanks mate just tryed it now its working will take the escort out to moz and c wot its like the sound of the lump has gon very deep lol grate thanks mate moggy

big_wasa - 14/7/15 at 08:27 PM

No probs, again I am learning not to just print gibberish with no reference.


I've also been asked for more info on the fuel pump driver modual, hope this helps.

Your-nme - 14/7/15 at 08:47 PM

Thanks for the info on the imrc connector. I had it wired correctly. I have ordered a new transistor for my IMRC because it holds it for a approx 10 seconds in shortrunner mode and then shuts of. After reading some forums in the usa about the focus svt I have seen some simularities with my lack of power. So hoping this is the solution on the p1518 failure code. Only leafs the p1380. Will keep on searching

big_wasa - 14/7/15 at 09:23 PM

Its one of the few donor bits that hold there value. They often sell for upto £100 used on ebay as there over £300 new.

rs moggy - 19/7/15 at 05:39 PM

hi woza can u post the OBD port plug and wer the 7 wires go please mate as i no some go to the oil temp and pressher gages im helping a mate with his loom and myin all in the car now and tuked away if you can please mate thanks moggy

big_wasa - 19/7/15 at 07:56 PM

I am sure the dash splices into the Standard corporate bus (scp).

Should be able to find the colours in the dash plug.

rs moggy - 20/7/15 at 01:44 PM

thanks mate i ow you a pint sound

Vindicator666 - 16/3/16 at 01:01 AM

Originally posted by big_wasa
Hi, great to see people using the info for projects instead of chucking a credit card at it.

I am no teacher so it is a guide with the important bits rather than a total a connects to b.

If I can be of any help then give me a shout but I can't take on any loom jobs at the moment as I have to much on.

Yours should be easier than most as its fwd to start with.

Cheers wasa

Just come across this post again after searching for 2 hours

fantastic post and perfect timing, i am just about to embark on stripping my standard loom out to attempt to wire up my car.

Have you got a contact number Wasa i can call you on for some advice on some basic ST170 queries re: inlet / carbs - ECU please?

Also how do you post pics on here as so as to show the project so far, im not to pc literate so any assistance appreciated

Regards Tobe Leigh

big_wasa - 16/3/16 at 01:37 PM

Hi good to see another project.

You have a pm

FamilyGuy - 2/5/16 at 07:46 AM

Hi wasa, I've been reading through the thread with a lot of interest as I am in the process of building an ST170 powered kit car. I have stripped the donor and have the full loom, I plan to use the standard ecu etc. I see no mention of the GEM module so I'm guessing this and all its associated connections are not required to run the engine?


big_wasa - 3/5/16 at 11:03 AM

Yep Engine ecu will run happily with out the body controle module .

FamilyGuy - 6/5/16 at 04:56 PM

Cheers, that's one headache I won't have to worry about. Not at the wiring stage of my project yet but I anticipate many more questions when I get there .

Vindicator666 - 19/5/16 at 02:21 PM

I have perm live going to pin 55 cam live
Perm to pats led
Pats Led to pin 42
Perm to switch
Switch to pats tranceiver

Earth to pats tranceiver
Earth to pin 24 earth
All chassis earth's conceded to chassis

The led flashes but when I switch it nothing happens

Does anyone know what I'm missing please ?


supersparks - 10/7/16 at 08:27 PM

Hi all this is my first post. I am thinking of doing this conversion so the information here is greatly welcome, a massive thumbs up to big_wasa. I have one question , what fuel pump would be required to run the st fuel rail I understand that the st fuel pump module varies the speed of the pump to achieve the pressure required but what pressure is needed ?.
Thanks, mick.

big_wasa - 10/7/16 at 08:46 PM

You are correct but the pump is just a pump. It does have a non return valve after the pump out let.

The pump on the vid is a generic bosch "style" pump as found in most 1990 cars like the sierra, xr3i ect. The valve was out of an st pump.

Case_Sensitive - 26/7/16 at 09:15 PM


my progress towards getting my ST170 pump going on a custom wiring loom is tipping away, but I'm having issues (I think) with the PATS.
As you noted way back, PATS / Immobiliser connector C390 varies in shape, colour and wire colour based on the year of manufacture and not necessarily like the Ford wiring diagram.

So, according to the Ford wiring diagram, the connector should have 4 female pins, with 5 wires:
p1 (Gn/Bk x 2)
p2 (Bk/Ye)
p3 (Gy/Ye)
p4 (Wh/Gn)

Well, mine is nothing like that at all!

Believe me, I tore the bag'o'wires to bits looking for one that matched the manual, it isn't there.
This is where my odd-looking connector came from, right under the barrel and attached to the PATS sensor ring.

This is my 8-pin female connector with 4 wires, which I've guessed is the same orientation, based on the colours for p1, p2 being about the same (fused +12v is usually some variety of green with trace, grounds black/black with trace)
p1 (Gn/Rd)
p2 (Bk/Og)
p3 (Bk/Wh)
p4 (Bk/Bu)

However, what concerns me slightly is that the Gn/Rd and Bk/Og are twisted tightly enough it can't be an accident, which in network cabling is a method of reducing interference. Why would you need to protect against interference on the power cables and not the data connections? The other two may simply be twisted at a different, much less frequent rate, and have become decoupled over the last 2.5 years though.

The other two go back to the ECU, so one of them carrying the wrong type of signal will at best confuse it.

So, having wired it like this, assuming that I had them in the right order, the car powers up in Pos I, II, but there's no turn over, because the starter relay inhibit is Open, along with all other 'active' connections to the ECU (Coil pack, Injectors, Fuel Pump Driver Module)

I've done some troubleshooting, and my next step is to start rewiring this plug until something magical happens.

big_wasa - 27/7/16 at 05:31 AM

I would be confident in saying that, that is not the plug for the Pats transceiver / aerial.

There is no aerial in your photo.

It looks more like the air bag clock spring. Any better photos ?

I will have a better look later.


Case_Sensitive - 28/7/16 at 11:58 AM

Ug, I went down to the garage, took a load of pictures, and of course, Big_wasa's right, I've connected what I assumed was the PATS ring to its connector, and wired it as if it were such.

Going back to the donor teardown pictures, the ring is present in Oct 2013, and completely missing 4 months later.
The wiring connector is more mysterious still, as it's present in pictures as recent as last August, but nowhere to be seen now.
Must be someplace, I'll rip the place apart at the weekend, and then hit the Wanted section of MEVowners after that. Lots of guys using aftermarket ECUs will have no need of immobiliser ring.

Whole album
plus older ones in an earlier one

Case_Sensitive - 9/8/16 at 06:02 PM

Yay! Fire!

After buying a PATS transducer ring and connector, and replacing the fuel pump (twice), my rats nest of wires makes LOUD NOISES!.

Thanks Big_wasa for the idea and for all the help, couldn't have done it otherwise.
I'll post my diagrams and wiring guide when it's all written up.

big_wasa - 9/8/16 at 06:34 PM

All good

bug1 - 23/8/16 at 09:24 PM

Hi this is very helpful but I have a question not near this point yet but I have a 2001 Mondeo engine and a 2002 ecu (2.0 duratec) the guy I got it from cut the loom and gave me an unmatched ecu another words not from the same car but was the same engine but I only got the ecu and nothing else am I stuffed or can I get it to work or do I have to get matched set of bits and will this guide suit that ecu. Thanks in advance.

big_wasa - 24/8/16 at 05:16 AM

The ecu is not matched or paired to the engine so an ecu from a late 2000 to a 2004 will be fine as long as you get a matching key and it's from a manual.

The pin numbers will not match the ones on my list so you would have some work on your hands, made harder for the first one with out a full loom to trace back.


bug1 - 24/8/16 at 05:42 AM

Ok thanks so I need to get an ecu from a 2001-2004 with key if I was to try and get a loom would I need a complete car loom. Thanks

adamswifty - 19/11/16 at 09:12 AM

Like to say thanks to thanks to Big_Wasa for the guide, finally got mine to fire up this week.

I think its fair to say the wiring is "not quite" upto Wasa's standards, though this is temporary and will be sorted when dropped into the Avon.

big_wasa - 19/11/16 at 08:59 PM

Well done.

Thanks for the post as it makes the work worth while.

Nourish - 21/12/16 at 10:03 AM

I found these Focus Wiring Diagrams - might heip someone

Matteoman - 31/1/17 at 02:27 PM

Hi there

Is big Wasa still reachable on this thread? Recently got an st170 running ford management but need some advice regarding the fuel pump driver module?

Would really appreciate some help.

Thanks everybody

big_wasa - 31/1/17 at 04:26 PM

Yep I am still around.

Matteoman - 31/1/17 at 05:56 PM

Fantastic as we're a little stuck

I've got an st engine in a Ka believe it or not and the loom has been made standalone by a friend it runs but the pump runs constant and Imrc operates fine but regarding the pump driver module does it operate as normal or?

I've checked all the pins on the module and they go where they should go. I've tried to check pin 1 is indeed switched earth but I don't think I'll see that without an oscilloscope.

Just after a bit of guidance we seem to of overcome all but this problem.


big_wasa - 31/1/17 at 06:39 PM

Pin 1 may not be as simple as a switched earth. It's more likely to be PWM pulse width modulation.

Matteoman - 31/1/17 at 06:57 PM

That's the diagram I have stored and all pins go to their corresponding locations. I've checked the pins on the pressure sensor on the rail and there also correct. I believe pin 1 and 7 on the pump driver to be canbus signals.

In running a cosworth intank fuel pump out into a 3 port fuel filter with a pressure reg built in then out to the rail

Just can't figure out why it just pumps constant and has no prime etc. When you do your modified looms do you just wire it as per how it was in focus's and how do you do you fuel piping?

Appreciate the guidance I read the whole thread hoping to find my answer but unfortunately didn't

big_wasa - 31/1/17 at 07:15 PM

Yes when I do a loom I take all the covering of and trace it back as far as I can. I don't think the driver has anything to do with canbus ?

Canbus is a high speed communications port. One ecu talking to another. Even the dash doesn't use Can it uses the slower bus.

The St170 is a returnless or dead head system. There is no fuel regulator. No return to the tank. There is a fuel damper. The only real difference between an st pump and an external pump is a one way check valve. I've took one to bits to have a look. In fact I nicked the check valve from it and put it on the Bosch style external pump.

Matteoman - 31/1/17 at 07:36 PM

Oh right, so if I understand you correctly the 2 pins connected to the ECU which are pwm would be used to control the speed of the pump?

The reason I put the pressure reg there was because we don't know what's causing my pump to run all the time and that made it semi returnless

We're just struggling to find out why it's not operating as it should and just constantly running the pump, it doesn't prime either. I guess what Im trying to ask is do you just use the pump module wired in as per the focus would and will it regulate a normal pump or will it only switch it on and off?

Thanks again. This the last hurdle I've got to overcome and I don't seem to be getting anywhere

big_wasa - 1/2/17 at 06:26 AM

I just wire every thing as it would be on the donor, chopping out any thing I think I can that won't be needed.

I no longer have access to good test equipment like an oscilloscope but my"feeling" is the pump will be pwm controlled instead of an on/off action.

But I don't know every thing and I am happy to be corrected if any one finds differant.

Again having butchered a few st pumps I found nothing special. It's just s motor.

One thing I found is the fuel rail pressure sensor can not be read on obd2 and the ecu controls the controller based on the fuel pressure sensor and other things.

I would check the wiring, change the fuel pressure sensor sensors and get rid of the fuel regulator.

Are you finding any fault codes ?


Matteoman - 3/2/17 at 02:50 PM

Hi again

Wiring checked and found a wire not correct so now it is as per focus the pump now stutters and shudders for a couple seconds then shuts off as if it's done a prime but it's not operating correctly still. Can't understand why it won't run smooth for a prime then power up again under cranking.

Do you have a feeling the vw 3 bar filter would cause it to stutter and judder? I can test it without if you think so. I just thought it was the pwm causing the stuttering/judder

big_wasa - 3/2/17 at 03:51 PM

3 bar filter ? Of you mean regulator, the shouldn't be any regulator.

What pump is it ?

Matteoman - 3/2/17 at 03:54 PM

I have a cosworth in tank fuel pump this isn't the issue

The fuel filter I fitted is a vw/Audi 3 port filter which has a built in 3 bar fuel pressure regulator. It made the system semi returnless but I think your gonna say yes that'll be my problem because it's got 3 bar up it all the time the pwm can't control it ?

big_wasa - 3/2/17 at 05:19 PM

I am not saying that is the problem but your saying that's the only thing not to Oem standard. Are you getting any obd2 codes to point you else where ?

Matteoman - 3/2/17 at 08:03 PM

Tonight I've removed the pressure reg filter and fitted just a normal fuel filter and tested it. Low and behold it primed and ran there is still a small judder of the pump on prime but it's loads better! Was yours a smooth prime?

Believe it or not I know my obd port works but I bought 3 code readers which aren't compatible with the st. Im bound to have codes because certain things aren't there anymore but all engine sensors are there and believed working

Matteoman - 3/2/17 at 08:27 PM

Also pin 3 can that be connected directly to fuel pump earth and pin 10 I've put through the inertia switch. Is this correct?

Really appreciate the help over the last couple of days. If you could confirm the above I think it's sorted

big_wasa - 3/2/17 at 08:55 PM

No the inertia switch is in the live between driver and pump.

Yes pin 3 direct to the pump

The cheap and nastiest of obd2 readers work on a petrol for. Again I would look at the wiring.

[Edited on 3/2/17 by big_wasa]

big_wasa - 3/2/17 at 08:59 PM

The prime was just a height pitch whine.

Matteoman - 3/2/17 at 09:10 PM

Ok so pin 3 is good
Pin 10 goes from the pump to the inertia which means it's using it then goes to the pump
I'll try the obd reader again as the man who did the loom was reading sensors from it when we first did it.

The prime works just stutters ever so slightly for some reason but it revs freely and comes off cold start fine and Imrc is fully functional

big_wasa - 3/2/17 at 09:13 PM

Yep pin 10 to inertia switch then to pump.

big_wasa - 3/2/17 at 09:16 PM

This is a bit of a project thread I did.

Matteoman - 3/2/17 at 09:16 PM

Perfect I think we over come everything then

Should I be worried about a little stutter during the prime? Or just keep an eye on it?


Matteoman - 3/2/17 at 09:23 PM

I'd read that thread on my lunch one day this week mate

The first picture on that shows the fuse box, I don't know if you used it or not but we didn't we just had a mini fuse box covering a couple things.

Should I be worried about a slight stutter when priming or just keep an eye on it?

big_wasa - 3/2/17 at 09:27 PM

H,m hard to say. Does the pump have a check valve to stop bleed of ?

big_wasa - 3/2/17 at 09:28 PM

No I don't use the fuse box but I start with as much as I can get my hands on to work it back. The Imrc is wired through it.

[Edited on 3/2/17 by big_wasa]

Matteoman - 3/2/17 at 09:32 PM

What's a check valve? There's nothing on the line it comes out the pump through a standard normal fuel filter and into the rail.

Ah cool much tidier doing your own mini box.

big_wasa - 3/2/17 at 09:41 PM

It's a non return valve after the pump ( inside the st surge pot) it stops the fuel bleeding back through the pump to the tank.

eBay Item

Matteoman - 3/2/17 at 09:50 PM

I don't believe there is a non return valve in the tank but I'll find out.

I must say when the fuel line and fuel filter was empty it primed fine im sure it did if that means anything

big_wasa - 3/2/17 at 09:55 PM

I am just wondering if the stutter is because it's going twice to build pressure ?

Matteoman - 3/2/17 at 09:58 PM

Do st's have any kind of fuel filter on them? That's the only thing I have in the feed to the rail from the tank. Odd how I think it primed fine when the filter and line was empty but I'll double check that tomorrow afternoon.

big_wasa - 3/2/17 at 10:05 PM

Standard pre and post pump filters. A nylon sack in the surge pot and a standard metal canister near the tank.

big_wasa - 3/2/17 at 10:06 PM

Being a non return system it could be stalling the pump ?

Matteoman - 3/2/17 at 10:09 PM

So my fuel line is identical to the st now then it's as you describe above.

Yeah I guess it's a possibility. Like I say it starts fine and revs fine. I guess the test is get it on open roads and see how it drives to highlight any possible issue

Davelarcs - 4/5/17 at 12:41 PM

Hi Guys, I'm a newbie to the site, been using this to set up an st170 for use in my Ford 100e, found it very handy, big shout out to Big Wassa for all the work he's put into this.

I've got a couple of questions, hopefully someone can answer.

On pin 7 on the OBD port, I've got a wire, but not sure where it goes? According to other stuff I,ve looked at it identifies to the reader what protocol it runs.

On the ECU pin 28 theres a wire "Telemetrics", can't find a home for this one either, does it go to the above pin 7?

Also my OBD doesn't have the pins for canbus, but the ECU does have the wires, can I add these if I use an atermarket OBD connector?

Hope these questions made sense, thanks for looking.

big_wasa - 4/5/17 at 04:47 PM

Pin 7

Could be to tell the reader what the protocol is. The reading I've done suggests it is to put the ecu into programming mode.

So your guess is as good as mine.


Again the ecu connects into things like the stereo and phone. Again I am not 100% sure on why but have read a few things but none relevant to an anglia. Leave it disconnected.

Davelarcs - 5/5/17 at 06:44 AM

Hi Big Wassa,

Thank you for your reply, I'll leave them both disconnected and see what happens, I'm waiting for an OBD reader to come in the post, once I've got that, I'll see if it connects, if not then I'll have a go again.

So far I've got the loom done and powered up to prove the PATS is working, still got a bit of work to do before I can test the engine with it.

big_wasa - 5/5/17 at 11:41 AM

Stick some photos up. It's good to see other projects and a big help to other projects seeing how it all fits in.

Big fitment issue being the inlet manifold.

Davelarcs - 8/5/17 at 06:27 AM

Will do when a get five, I,ve flipped the inlet up-side-down and had to fabricate a new fuel rail, sump, pick-up pipe, at this stage still hoping its gonna work.

Davelarcs - 11/5/17 at 01:37 PM

Here follows some pics:

Hopefully these have worked, been a while since I did this..

Home made exhaust manifold from the scrap bin of the local exhaust shop.


[Edited on 11/5/17 by Davelarcs]

Davelarcs - 11/5/17 at 02:20 PM

OK? What am I doinf wrong? Just checked this and I can't see any pics, just the URL stuff. I'm clearly being a bit dim here

big_wasa - 11/5/17 at 06:00 PM

big_wasa - 11/5/17 at 06:02 PM

Photo bucket is naf.

I would love to see a vid of if running when your done.

Mash - 11/5/17 at 09:29 PM

Originally posted by big_wasa

Great to see progress at least I know some one tried it.

Hi BW, sorry to hijack your thread, but I have an ST170 (looking to convert it to RWD eventually) and I have a silly question.

what's the software you use to interrogate it in this video? I have ELM2 set up but I don't seem to get as much info from it and don't get any live data

I have a really daft problem at the mo, having swapped out the seats for RS Sparco ones, and they don't have airbags and the OEM seats do, I now have an airbag light constantly on. I am playing with resistors to try and compensate, but if that fails I'd like to just turn them off, as this must be the cae with the MK1 RS, so better software would help.

thanks in advance,


big_wasa - 12/5/17 at 10:53 AM

That's not my software or laptop. I just put the vid on for the guy.

I used the software that came with the cloned Elm dongle.

're your seat belt pre tensioners. On my Scooby I used the resistor mod and it worked fine until I bought the hardware to do it properly. A Tactic dongle.

On a Ford of St170 vintage. The engine ecu is just that. There is a Bcu, also known as a Gem's for the car body stuff.

There is a modified Elm that has been made to right to the modual. You have to join a website and apply and be accepted to get the software. I bought the dongle months ago but hav'nt had the time or inclination to get the software yet.

I will get you some details over the weekend. I need to sort it so I can look into a second lambda delete for a decat on an Rs controlled hybrid engine.

Mash - 12/5/17 at 06:45 PM

cheers Mate, that would be really helpful.

I'm also considering getting an airbag module from an RS Mk1 which should have no side airbags but still have the passenger and driver front airbags. Thatt way I reckon I could just swap mine for it and it should work, but we'll see......

By the way, you're the fist person who hasn't said I'm mad for wanting a rwd ST170

big_wasa - 12/5/17 at 06:55 PM

Rwd anything is a thumbs up. Shame the focus rust out so fast.

Mash - 16/5/17 at 02:50 PM

Originally posted by Your-nme
Small update: the engine is running well.
Have two questions and hope you can help.
1. The hose thet is inbetween the air intake and the airchamber below the cilinders (you had closed this part). I'm having a high vacuum that the hose closes itself. Is that ok?
2. Trying to connect a digidash2 lite. Have to connet the tacho to the ecu. Read that pin 48 is for the tacho in many forums but that is only for the zetec ecu. Is there a pin on the st170 that does the trick? Have been searching the web but no succes until now.

Hi there Mate

Can you tell me what software you're running with the OBD and where you got it? I have ELM2 and have tried Forscan and others but I don't get the level of detail you show in your video.

Cheers, Mash

Matteoman - 22/5/17 at 09:06 PM

Hi there

Big Wasa if your around could I ask a question regarding the obd plug pinout?

I can't seem to gain access and have checked my pins towards your diagram, I found pin 14 of the obd plug isn't there at all and pin 6 isn't there either but I have a pin 7? All other pins on your diagram match up and go to the corresponding locations.

Many thanks

big_wasa - 23/5/17 at 03:35 PM

Is this an st170 loom and plug ?

None Can enabled cars are missing the two pins you describe. This is a fiesta obd2

Matteoman - 24/5/17 at 08:02 AM

Originally posted by big_wasa
I am sure the dash splices into the Standard corporate bus (scp).

Should be able to find the colours in the dash plug.

Hi Wasa on page 3 of this thread it shows your comment with an obd plug pin out. 14 + 6 show as CAN wires. Which are what's missing on mine

That picture you've just put up I have all them pins intact and I have that pin 7

I don't know if our st's have these pins or not

Thanks mate

adamswifty - 24/5/17 at 02:21 PM

I've just had a look at mine as this rang a bell, it looks like i added 6 and 14 to the connector. Cannot recall if it was needed in the end and the engine is not in a state to test, though no harm adding?

big_wasa - 24/5/17 at 05:19 PM

Originally posted by MatteomanI don't know if our st's have these pins or not ,Thanks mate

is this a uk St170 ?

ive played with a few and they all have had the can function.

Matteoman - 24/5/17 at 05:22 PM

Yeah I believe it was a UK car. In that case I imagine the guy who did my loom removed the pins by mistake. Im dead sure he had communication with the ECU when we first test fired it.

big_wasa - 24/5/17 at 09:22 PM

More likley he used a base model obd2 plug.

You shouldn't need the Can bus to connect to the ecu via obd2. There is the other bus port.

Matteoman - 25/5/17 at 07:27 AM

Oh right. So them 2 pins may not be needed to connect and view live data and codes?

If you don't mind me asking what diagnostic software do you use? It'd be good to see all the sensor data on a PC

big_wasa - 25/5/17 at 11:28 AM

Yes I am sure it would use the scp bus.

Software, I usually use Torque on my android phone. I couldn't use my phone for obd2 and the video so I bought a cheap dongle from eBay and used the software on the disc. I've since given it away. I've now bought Forscan but I haven't had time to play with it much yet.

Matteoman - 25/5/17 at 12:01 PM

Hmm I wonder why I can't connect then. Maybe the 3 readers i tried aren't compatible would of thought works snap on would do it though. I need to find out what Bluetooth dongle st users use and can confirm work

big_wasa - 25/5/17 at 01:43 PM

Chinese nock off of an Elm427 from memory. Not all nock offs are equal.

If you have had three scanners on it with no luck then an Elm clone is not going to help.

Look at the wiring again. Double check wiring faults. Good power and earths.

Matteoman - 25/5/17 at 02:07 PM

I've checked all the wires from plug to ECU and they are all connected I just don't have pin 14 and 6.

Maybe I'll try an elm reader. As I don't see any other reason it won't connect. Power and earths are fine I checked them too. The engines fully running and full Imrc control so I imagine it's probably happy but I want to see sensors

filstu - 6/6/17 at 11:22 AM

Hi Big_Wasa. Great work. i have been working through your guide and the ford wiring stuff, so far so good however my fuse box loom was cut when i received it and i cannot find the IMRC control plug or wiring! whereabouts is it located on the loom do you recall?

A couple more questions, what did you do about the canister purge solenoid and associated parts to prevent throwing codes? you mention a load or mil circuit? but i cant find any more info?

The engine is going in a Haynes roadster project

big_wasa - 6/6/17 at 03:51 PM

Hi, from memory there is two really big square plugs near the base of the fuse box, grey and the other brown. Joining into his is the imrc plug on its own, fairly long lead from memory around 30cm.

The canister purge is just a solenoid, power and switched earh. I put a resistor in there so the ecu can see a load. I am working on one at the moment so I may look into that further.

filstu - 7/6/17 at 10:49 AM

Awesome, looks like the loom I have was cut below that connection ☹️Managed to get a connector from eBay. So I just need to solder a resistor between the purge solenoid pins? Do you remember the value?
Just one more question. The diagram I have seems to show eldis supply from ignition not k13. Is that as you recall or is it best to go to the 30a side of K13?
Thanks for the invaluable help👏👍

Davelarcs - 23/6/17 at 06:52 AM

Hi all

I've got a problem with no signal to the injectors

I'm turning the engine over directly from the starter soleniod, got spark, fuel pump is running as it should, i.e. its runs briefly when ignition turned on, then runs while engine cranking.

IMRC does'nt seem do do anything, but if I'm correct, it does'nt come in till after 5000 revs?

I've got a good 12v to the injectors, but the ecu is not grounding them, I've double checked all wires from injectors are back to ecu as they should be.

I've checked the grounds from the ecu as per the pinout are sound.

I must be missing something simple here, I know the ecu was a runner, as I broke the st170 it came out of, and it ran.

Still unsure about a couple of wires: Start inhibit relay pin 27 & engine run relay 46 (I guessed that these are bypassed) thried earthing both but no difference.

I've even hot wired injector 1 to spay some fuel in, and then the engine is trying to fire, so ignition side seems fine.

Can't get the obd reader to connect either, which would help a lot.

Any help will be much appreciated, ta.

big_wasa - 26/6/17 at 03:46 PM

I am told the ignition circuit is not immobilised, never tried it. Injectors are and your bypassing the starter. Sounds to me like its immobilised. What's the pats indication light doing ?

big_wasa - 26/6/17 at 03:49 PM

Originally posted by filstu
Awesome, looks like the loom I have was cut below that connection ☹️Managed to get a connector from eBay. So I just need to solder a resistor between the purge solenoid pins? Do you remember the value?
Just one more question. The diagram I have seems to show eldis supply from ignition not k13. Is that as you recall or is it best to go to the 30a side of K13?
Thanks for the invaluable help👏👍

Sorry I missed this. I don't use the donor fuse box.

Davelarcs - 26/6/17 at 04:04 PM

Hi Big Wassa, thanks for the reply, the imboliser light is flashing when ingition off, when flick switch for ignition, it goes solid for a few seconds, then goes off.

big_wasa - 26/6/17 at 07:48 PM

Yep that's what it should do.

big_wasa - 27/6/17 at 09:27 AM

My next guess would be crank sensor. If the ecu doesn't see the engine turning over it won't put fuel in.

Check the wiring on this.

Davelarcs - 27/6/17 at 01:46 PM

I'll double check that later, but it I am getting a regular spark, so presumed crank sensor ok?
With the engine run relay & inhibit relay, I've presumed that I can bypass these, and have Ignition live going straight to the ecu, and I'm hot wiring the starter for now just to see if it'll run, how do these normally link up? are they controlled by the ecu?

I've seen elsewhere that the start relay is spliced (ecu pin 32) to the knock sensor, I've not got anything other than the ecu from pin 32 connected to this? I can't immagine why this would be, but starting to grasp straws now.

[Edited on 27/6/17 by Davelarcs]

Davelarcs - 28/6/17 at 06:18 PM


After a fair bit of checking wire for wire, I discovered that ford in their wisdom made the plug for the fuel pressure sensor the same as the one for the T.P.S. mix them up and it wont work strangley enough .

Starts and revs up ok, no cooling set up yet, so only a quick fire up. Much happiness.

Thanks again for your input.

big_wasa - 29/6/17 at 06:53 AM

Sorry I Have been a bit slow replying this week.

Yes if the tps was showing wot ( wide open throttle) then it cuts the fuel when cranking to clear flooding of the engine.

allaboutfords2012 - 16/11/17 at 10:41 PM

Hi there I am just starting to put an ST170 engine in a Westfield SE. I have a complete ST and was planning on stripping the loom back while it was in the car so I could keep testing it as I removed stuff is this a good idea or not? I also wanted to run it on throttle bodies and junk the manifold I will still have the airflow connected unless there is a way to convert it to map sensor?. If the manifold runner is unplugged does it go into limp or just bring the light on? If its limp can I just leave that plugged in but not connected? Hopefully going to start pulling bits off it this weekend and get started on it.
Thanks for any answers in advance

big_wasa - 17/11/17 at 07:48 AM

With out the inlet manifold runner controle modual plugged in and working it will peg the power back to around that of a standard Blacktop. It will show errors in the ecu but not a full on limp home mode or engine managment light on the dash. If you plug it in with out it pulling the manifold lever it will do the same. If you get the modual to just pull a spring then that should be better but you will get a flat spot.

The only real way you can get the Oem ecu to work is with the full count of sensors itís mapped for.

Standard Zetec and Focus Rs Turbo are easier to package and you have more freedom to change inlets and exhausts and still keep the Oem sensors.

allaboutfords2012 - 17/11/17 at 08:03 AM

Thanks for that did I read that you can turn the inlet manifold upside down for space reasons when fitting to a westi?

big_wasa - 17/11/17 at 11:05 AM

A few people have, even one in an mg. you may be able to move the engine over a touch. All depends on steering down lincs ect.

Pigsy - 19/6/18 at 10:29 PM

Hi Big Wasa. Are you still around and able to answer a few questions on this posting?
Im trying to do what you have done. I now have a complete loom, but not all the components they plug in to. I have a few to purchase in this case. I have all the injectors, Crank sensor, coil, throttle position sensor, fuel rail pressure plug in (and sensor?), Inlet air temperature sensor, VVT setup, cam position sensor, water temp sensor, fuel pressure driver module and the sensor with the red button (shut ff in an accident?)

Probably one or two others. Please, could I prevail on your patience and ask what else I need. Im learning as I go, but slowly. Give me anything mechanical and it will be no problem, but wiring leaves me cold. I have allready wired up the lights, indicators, horn, brake lights, interior fan, engine fan and one or two other things. I want to keep the engine management side with fuel pump setup seperate from the other loom if possible.
Any help would be much appreciated. Pigsy.

big_wasa - 20/6/18 at 07:07 AM

Yep still about.

I will see if I can fill in the blanks for you later.


Pigsy - 20/6/18 at 11:42 AM

Thanks very much.

big_wasa - 20/6/18 at 05:38 PM


Crank pick up.
Cam pick up.
Engine coolant sensor.
Vvt solenoid.
Pre and post O2
Fuel pump control modual.
Barametric sensor.

[Edited on 21/6/18 by big_wasa]

FamilyGuy - 20/6/18 at 05:41 PM

Hi Big Wasa,
I'm in the process of wiring up my st170 engine. I've basically cut all of the required connectors off the loom and I'm connecting them all back up individually. I have all ecu connections wired up and am waiting for delivery of my relays / fuse box to crack on with that.
I'm not sure if the oil temp/pressure sensor is required to run the engine. This only has 1 wire and I can't see that it connects to the ecu. Any advice on this is appreciated!

big_wasa - 20/6/18 at 05:52 PM

There are no sensors. The oil pod is driven by the ecu and is just a gimmick.

big_wasa - 20/6/18 at 06:02 PM

If you use the dash in your build the pod has an illuminesant back light driver in it.

Pigsy - 20/6/18 at 09:17 PM

Thanks for that. There are a few things I need and this list is a great help.Thanks Mate.

FamilyGuy - 20/6/18 at 09:24 PM

Great thanks. I'm not using the focus dash so I can just forget about it.

big_wasa - 21/6/18 at 05:27 AM

Yes just forget about the dash.

FamilyGuy - 22/6/18 at 11:18 AM

Originally posted by big_wasa
Yes just forget about the dash.

Just to confirm, this is the plug next to the oil filter that I am referring to. So I don't need to connect this up to anything???

big_wasa - 22/6/18 at 11:27 AM

That's you're low oil pressure warning light.
Standard ford .
It does not sense pressure or temperature for the st oil pod. That connects to what ever dash or warning lights that your using and warns you of low oil pressure but if it comes on while driving its probably to late any way.

FamilyGuy - 22/6/18 at 06:19 PM

Great, Thanks!

Pigsy - 23/6/18 at 05:03 PM

Big Wasa, are you aware of any programs that will enable me to go into the standard st170 ecu that will enable me to change the crankshaft sensors angle? I donít want to disassemble the engine box setup fitted to the car. Itís in an MGB GT and space is VERY tight. Has an RX8 box. I cannot just drop the box from the engine due to MGB engineeringís cross braces. Thanks mate.

big_wasa - 23/6/18 at 05:40 PM

As per your other post, I donít think it can be done. Up until not long ago you couldnít do anything diy to these ecuís. You can look at a project called Forscan. There was other projects in America where these are used much more than here but you will need good computer programmer and microelectronic knowledge. I tried but itís way way over my head.

A stock flywheel can not be out, so how have you set up the trigger ?


Pigsy - 25/6/18 at 06:16 AM

No it cant, but the stock 36-1 wheel can be out on the flywheel. I have a new wheel setup on the front crank pulley. where I fitted the rx8 box, I had to swap the starter over to the right hand side of the engine. I can physically see the reluctor wheel and just counted its teeth as I rotated it. Its an unusual reluctor shape.

Pigsy - 26/6/18 at 12:24 PM

I have a2003 st170 loom that I bought on ebay. Its in 3 sections. One is the relatively short one that contains all the engine sensors and ecu.There is a tail near the ecu that has a plug that fits the fuel pump controller and then goes on to what could be the fuel pump plug It has an approx 2.5" or 6cm grommet attached. Can anyone confirm if this is the same tail used for the regulator and pump? If not, how do I find out where they attach? As Ive not physically striped loom from a car I just don't know. Thanks

big_wasa - 26/6/18 at 02:24 PM

Yep itís the fuel pump driver then the fuel pump / sender plug.

Easy way to tell is by the wire colours as Iíve listed the ecu end or you can use a multi meter to do th3 same.


Pigsy - 26/6/18 at 05:27 PM

Once again, you are great at help. Thanks very much.

Pigsy - 28/6/18 at 10:55 PM

Hi, how many o2 {lambda} sensors will I need to run on the st 170 engine? I have NO cat, so are both needed? You mention these on the ECU:
35 white/redó HSO2 1 pin 4.†
60 white -- HO2S 1 signal†
93 black/yellow -- HO2S 1 heater control.†
100 black/blue Ė HO2S 2 pin 2.
Do they both have the same wiring? What are the loom colours pre and post cat please?

I have seen this sensor on ebay for the ST170: ype%3AST170&epid=2235969017&hash=item28487e77b3:g:ONAAAOSwC81as17B#vi-ilComp

As with all the searches I have done, no mention pre and post cat sensors.

I already have 2 sensors that were supposed to be pre and post cat, but are absolutely identical in every way including manufacturers numbers. Me thinks someone is having a laugh at my expense!

I just cannot find a diagram that shows which of their 4 wires: 2 whites, a black and a grey match the ST170 o2 wire colours, or I have and do not realise it.

In one of your videos they are both just hanging over the exhaust ports. Is that all thats needed? Just about a foot apart in the exhaust down-pipe?

Sorry to be a total pain in the butt, but I'm close now and have spent a lot of time on it, working into to the early hours. What you have posted has been tremendously helpful.

I only have the IMRC to arrive and fit, the pump to wire in, the loom to thin out, the 36-1 front wheel sensor to test and the ECU to fit into the car cabin.

big_wasa - 29/6/18 at 05:36 PM

Pre cat is the green plug and post cat is blue. Yes you need both unless you get the second mapped out. If not and you have no car then you will need a cheat device. There are plug diagrams that show wire colours.

Aftermarket are often universal.

No they wonít work in free air, that was just for a quick start up.


Pigsy - 29/6/18 at 11:04 PM

Thanks. Ive almost wired in the IMRC that arrived today. Must the cable end be connected? I have bike throttle bodies. Was it used to reduce air flow into the inlet manifold when the flap was closed? A sort of choke?

big_wasa - 30/6/18 at 08:09 AM

It needs to pull somthing or it will log a code and peg it back. Make a spring so it pulls that.

Itís a dual stage inlet manifold not a chock. So it makes the runner length longer for more torque and shorter for more revs.

Pigsy - 30/6/18 at 08:40 PM

Aaaah. I see. It has a spring built into the main body, but I will add one in. Itís very interesting.

big_wasa - 30/6/18 at 08:53 PM

Yes its sping loaded, just replicate it. So the ecu thinks it knows if the manifold is long or short.

From memory its short at idle, long in the midrange going short again at the top.

You need to use the st injectors not the bike ones.

[Edited on 30/6/18 by big_wasa]

Pigsy - 1/7/18 at 10:44 AM

Im already using st injectors and have just fitted a bracket and spring to the imrc for when it pulls the cable. What about the intake manifold tuning valve and the imrc solenoid? Solenoid I can just fit. Is the imtv necessary?

big_wasa - 1/7/18 at 01:27 PM

Imtv solenoid ?

Pigsy - 2/7/18 at 06:44 AM

I watched an item on youtube. They mentioned it frequently. Its on USA 2.4 svt's. Ive not had a complete car so didn't know if it was necessary.

Pigsy - 2/7/18 at 06:48 AM

And the Ford Vacuum Solenoid Valve Intake Manifold Runner Control 4M5G-9J559-NB? Is this necessary?

big_wasa - 2/7/18 at 07:14 AM

If its what I think you mean then the st170 doesn't have one. Although it's badged as a Duratec it is a Zetec.

What your referring to looks to operate the swirl flaps on a Duratec.

There is a canister purge solenoid. This vents the fuel vapour from the tank, into the charcoal canister then via the solenoid into the inlet manifold.

With out it, it will give a fault code in the ecu. This may or may not affect performance.

You can unclip the canister from the solenoid and just plug it in. You could replicate the load with resistors. You could ignore it and see how you get on.

I've done all three and the first option is the easiest.

Pigsy - 2/7/18 at 06:38 PM

Do you mean just plug the solenoid in? Or the canister without the solenoid?
With the diagnostic link connector, I have:
Pin two, grey/red wire,
Pin 4, black wire,
Pin 5, black/orange wire,
Pin 7, white/black wire,
Pin 10, blue/red,
Pin 13, black/orange,
Pin 16, orange wire.

ECU pin 13 modal prog requires orange/black, do I connect to either pin 5 or 13 or both?
ECU pin 15 blue/black is scp-, which colour is for scp + ECU pin 16?
ECU pin 49, blue/red is can- from plug pin 10,and
ECU pin50, grey/red is can+ from plug pin 2, that is only 5 wires of 7 connected.
Are the 2 other wires used? If so where?
Sorry for so many questions. Just want to get it right.

I just have to fit the O2 sensors now having extended their leads about 30" and the OBDB2. Without these I'm getting a slow flash from the led, but when I activate the switched 12v with ignition, it just flashes very quickly. there was no fuel pump sound either. Your thoughts would help me as to me it could be caused by so many things like the lack of the solenoid or the canister, so please help me a little more. I still wish I had your knowledge.

big_wasa - 2/7/18 at 06:53 PM

Starting with the Immobilizer.

You donít need anything engine related to operate or test it.

Just the lives and the earths, the four wires to the antenna and the two wires to the led.

big_wasa - 2/7/18 at 06:59 PM

The solenoid just unclips from the canister purge valve. Just plug it in and the ecu is happy. On that front any way. The ecu can tell the circuit is live and drawing current and thatís why it could be replaced with a dummy load.

big_wasa - 2/7/18 at 07:04 PM

I am not sure what you mean by the rest.

There will be other wires in the dlc for other non engine diagnostics

Pigsy - 2/7/18 at 07:06 PM

I have the canister with the two pin connector to the top. I did not know what it was!! Tried googling the numbers with no info supplied. I gather the solenoid connection must be near the inlet manifold. Which bit of loom if you know please?

Pigsy - 2/7/18 at 07:12 PM

Thanks for the info. Do I need to add chassis earths to the ecu. The brown is common. Does it connect the the car body or engine in anyway, or is it just in the loom.

big_wasa - 2/7/18 at 07:13 PM

It sits on the bulkhead and connects to the inlet manifold with a hard plastic pipe. And another pipe to the fuel tank. The plug will be on the engine bay / fuse box loom.

This is one circuit you could come back to.

big_wasa - 2/7/18 at 07:20 PM

The common brown is shared with the sensors it does Not go to chassis earth.

There are four black / yellow wires that go to earth. They can go to the same point. There is. Fith Black / red earth thatís meant to go to a separate earth but for testing it can go to the same place as the others.

Pigsy - 2/7/18 at 07:45 PM


FamilyGuy - 3/7/18 at 09:15 AM

Just reading previous post on Evap canister and hoping I haven't thrown mine away :/

I want to test my ecu immobiliser, as in your video, but I'm unsure about one of the wires (pin 2) on the PATS receiver plug, is this just an earth. I have other connections as below.

Pin 1 - 7.5A fused +12v
Pin 2 - bk/ye wire. Is this an earth
Pin 3 - ecu 19
Pin 4 - ecu 53

big_wasa - 3/7/18 at 09:27 AM

Yes chassis earth. If connecting it to the steering column make sure it's got a good earth and isn't isolated by bushes.

Pigsy - 3/7/18 at 12:38 PM

I have sussed out the fuel pump, at least, it primes when ignition is on. I have practically everything connected already, and so to just do the connection from your video to get the flashing led right will take forever to disconnect everything and then reconnect it all. Without ignition on it flashes slowly. with it on very quickly. My obdb2 sensor is about 5 years old. Is it up to the job? With connecting it (with the correct port wires fitted) it scans all the details but just cuts out and restarts when I try to test for faults. Any ideas why?

Pigsy - 3/7/18 at 12:51 PM

For OBD2 read DLC

big_wasa - 3/7/18 at 01:56 PM

I have three obd2 tools one is around five years old one is well over that and they all do the basics just fine.

The light flashing quickly when powering up is the immobilizer being triggered.

It's very low power and is sensitive to position.

Power or earth fault to the antenna.

Power or earth fault to the ecu.

Send and receive the wrong way around.

You don't have to strip the loom down the point was the other circuits or lack off won't affect the immobilizer working or not.

Some times when the immobilizer is triggered and there is no fault ie the key was not close enough then you may have to disconnect from the battery to clear it.

[Edited on 3/7/18 by big_wasa]

big_wasa - 3/7/18 at 02:03 PM

To add one point. you havnt purchased a flashing led have you ? It should be a plain led with around a 600 ohm resistor pre wired ( depending on colour).

Pigsy - 3/7/18 at 05:35 PM

Ahaaa. It may be. I think I have some others that do not. It has a slow rhythmic flash until ignition is on. then it goes very quickly.

I have connected the O2 sensors now as well. They are the same pre and post cat on this car year.

The reader can tell if the engine is cranking at 250rpm so I guess the crank sensor works.(No spark though). It reads inlet temp and coolant temp. It reads others that make no sense to me with my limited knowledge.But, the reader still just switches off if I press enter to check for faults.

The pump is priming. I have used as much of the standard loom as possible and feel that I have not connected something like chassis earths properly. Should I take all the earth pins from the ecu (apart from brown) and ground them as well? Perhaps the common brown is broken somewhere.

I have connected all the inputs to the ecu where you have indicated from the pats, the fuel system, the key setup etc. Actually have you any other diagrams of the key and ring setup with colour codes, in case I have it wrong.

Is this the time to strip down the loom to see if all the correct wires are connected from the sensors to the ecu? Should I just remove the unnecessary wires?

I am making a fundamental error and its frustrating. Is there any way of checking the ecu itself just in case this is the problem? It may have been blown and sold as good.The car it came from was running in limp mode and had a fault, though I cannot find out what it was. The breaker did not mention this. I found out on thnet using its registration number which I insisted on having.

big_wasa - 3/7/18 at 07:39 PM

The brown is shared amongst sensors and does not go any where near chassis earth.

The five earth go to the chassis, or for testing direct to the battery negative.

You have the memory live that is always live.

You have two switched lives that become live when the ignition is turned to run.

From memory the power supply for the antenna is also a switched live.

The power supply for the DLC can be either.

You would be hard pressed to find an St170 that wasnít in limp home mode. Two most common faults are the Imrc and the O2 sensor. There is loads of info on the net on how to fix the Imrc.
The o2 sensors have unique plugs for pre and post, pre is green post is blue. The cheap chinease o2 sensors will plug into both so I guess you could use what ever you have as long as you get them the correct way around.

big_wasa - 3/7/18 at 07:41 PM

big_wasa - 3/7/18 at 07:44 PM

Sort the Immobilizer before going forward. It wonít start with out it working.

Pigsy - 3/7/18 at 09:04 PM

Thanks for your help. The sketch looks helpful too. I will have another go at it tomorrow.. thankfully I have the day off.

big_wasa - 4/7/18 at 05:07 AM

Remember to use the pin numbers from the guide not the sketch although the Rs is probably the same anyway.

Pin 1 is the one nearest the release clip on the antenna plug.

Pigsy - 4/7/18 at 09:54 PM

Hi. Replaced the LED and still the same problem. I rewired it completely and it made no difference. The penny then dropped and I realised that I had been splicing the connections in to the wires leading to the ECU from the engine loom, so I un-spliced them and just connected the wires from the pats module to the ECU without the wires leading off into the engine loom as they had been. Bingo, the light behaved well as it should, BUT, still no spark.

I then tried to do the same with all the other wires that I have patched into the loom (DLC, fuel pump, 12v+ to the ECU, etc). Do these connections need to carry on into the engine loom from the ECU?

I also opened up the loom corrugated protection to see if anything was not right. The wire to the coil live feed (pin 2) went nowhere, so I fitted a switched live. Still no spark. Then I noticed that somewhere along the line the led started its old tricks of the fast flashing. This is in the car cockpit and the engine loom with ECU is under the bonnet. Ive now managed to get the ECU into the passengers footwell and it will fit under the dashboard.

Also, a wire from the knock sensor went nowhere as well as one from the IMRC. I will trace all the wires and work them back to their correct connections on the ECU. It will be next week now.

Sorry to be a pain in the backside, but your help is invaluable. If you can see that Ive made another boob please just say. Thanks mate.

big_wasa - 5/7/18 at 07:43 PM

I donít know if I asked what your putting it in ? This will affect if any wires are shared.

Pigsy - 5/7/18 at 09:43 PM

It is into an mgb gt. I have kept to the st loom as much as possible using the mg loom for lights, wipers, heater fan,and indicators. The ignition switch to supply switched live to the st ecu relay. A permanent live comes from the mg loom for those bits that need it like keep alive memory. I think Iím just going to have to trace each sensor wire back to the loo ecu and make sure they donít just go nowhere as with the others I found. Thanks.

big_wasa - 6/7/18 at 05:14 AM

Ha now we are getting some where.

If your not using stuff like the St170 dash, abs and so on the signals don't need to be shared.

The oem had two layers of security. Pats ( passive anti theft ) the immobilizer. And the active anti theft which is the alarm done by the bcu body control unit.

I don't get into that much but on earlier set ups they looped vairious lives and earths through it as part of the security system.

I would strip the loom down.

[Edited on 6/7/18 by big_wasa]

Pigsy - 6/7/18 at 07:28 AM

Im using as much original mg as possible like the dash, switches etc. The ecu has its own power source from the ignition key. The starter setup is separate as well with its own supply to the starter relay and the racing type push button and switch setup as you did in your video (ok, hands up, Im a copy cat). yet, in spite of this, the ecu managed to supply an influence over fuel pump as it was originally wired. Somehow it back fed current from the ecu. Its now directly to the ecu and working.
So Im stripping this evening!

Pigsy - 6/7/18 at 11:02 PM

Does the smart charge on the alternator need to be connected for the ecu to work? Just needs power to the red wire, but I need a silver calcium battery I believe. Will it run on a standard lead acid battery? I know it pokes +/- 14.5 volts and probably won't be a good idea. What does everyone else do?

big_wasa - 7/7/18 at 12:02 PM

It's meant to be a silver calcium battery to handle the higher voltage but stick your head under an old ford and you will be hard pushed to find one due to cost.

You don't need any connection to the alternator for it to charge. Unlike a traditional alternator it will self excite. There is no facility for it to turn the light on the dash on or of. This is done by the bus network.

The red wire is for voltage reference.

Pigsy - 7/7/18 at 10:35 PM

Thanks mate. Im still tracing all the wires down. Im getting there. I really want to finish it this month.

FamilyGuy - 8/7/18 at 01:37 PM

Hi Big Wasa

I got some good signs of life out of my loom today. Initially was trying to get the immobiliser to disarm and was having trouble with just the perm live PATS receiver and grounds connected. I then tried firing up the power hold relay and the led came on solid for a few seconds then went out so it looks like it's working
The fuel pump also kicked in and primed for a few seconds which is a good sign. Not sure what I was doing wrong to be unable to get the immobiliser to disarm without the power hold relay but it all seems ok now.

What I now need to do is tidy up the loom and sort out the fuses (which I'm hoping you could give me some advice on )

I have the high load side of the power hold relay fused at 20A, this feeds to various different sensors etc and the pre and post cat 02 sensors which have an additional 10A fuse. I have no other fuses on the PHR

The feed to the PHR will be fed through the v33 diode as per focus set up but my main question is what fuses I need on the low load side of the relays, if any.

Apologies for the essay but I appreciate any advice on this.

big_wasa - 9/7/18 at 10:24 AM

I tend to over use fuses. So one of my engines will normally have between six and ten fuses. It makes fault finding easier.

FamilyGuy - 9/7/18 at 04:13 PM

Originally posted by big_wasa
I tend to over use fuses. So one of my engines will normally have between six and ten fuses. It makes fault finding easier.

So do you fuse the coil side of the relay as well, if so what size fuse do you use. What I've seen so far on the net is that a typical 40A relay coil would typically draw 150 - 200 mAh current. I'm thinking if this is the case then I can just fuse the trigger side of the relay with a small fuse for peace of mind.

Also do you know a suitable fuse for the coil pack 12v supply?


Pigsy - 9/7/18 at 10:23 PM

I don't have the ST170 alarm box ecu 2S7T-15K600-NC. Is this a problem that would stop my engine firing? What is the most likely thing to cause no spark apart from PATS?

Can anyone recommend the best obd2 program? Forscan? I have the elm327 unit (not chinese) to link up with.

Pigsy - 9/7/18 at 10:25 PM

What is the PHR please?

big_wasa - 10/7/18 at 09:36 AM

No you don't need the gems modual ie the body control modual.

You don't even need the power hold relay if you have really chunky ignition switch gear but I do now use one as the sierra switches are getting harder to find.

The last one I did, I used the heavy duty 70a grey relay I pulled out of the spares tin.

For everything else apart from the fan I use the yellow 40a relay from all Rover's as I used to be able to get them cheap from the breakers but unfortunately they are no more due to eu bursary

FamilyGuy - 10/7/18 at 06:42 PM

Originally posted by Pigsy
What is the PHR please?

Power hold relay.

I've used 3 relays in my set up. One for fuel pump, one for starter solenoid and power hold relay. After a bit of advice I've linked the coil pack common to the PHR as opposed to direct from the ignition as per focus set up as this was simpler for me.

I'm hoping to fire the engine up soon but what OBD reader / software should i be using to check for any faults etc? I need a budget friendly option :/

big_wasa - 10/7/18 at 07:07 PM

Forscan is great but overkill for little jobs I use an app called Torque on my android phone with a cheap clone elm dongle.

FamilyGuy - 10/7/18 at 07:16 PM

The latter sounds right up my street.

This sort of dongle?

big_wasa - 10/7/18 at 07:40 PM

eBay Item

Mine looks like the above and cost around the same but do your homework as not all are equal.

FamilyGuy - 10/7/18 at 08:16 PM

Cheers I'll give one a go.

FamilyGuy - 10/7/18 at 08:59 PM

Gone for one of these based on reviews. If it's no good it's no worse than a spilt pint in an expensive pub

[Edited on 10/7/18 by FamilyGuy]

Pigsy - 10/7/18 at 09:06 PM

Thanks very much for that. I will look into torque.

Pigsy - 12/7/18 at 06:38 PM

I have had a slow power drain problem that I have been searching for. I completely dismantled the ecu etc to check everything and have been slowly putting it back together while looking for problems. Then I noticed that the alternator was pretty warm. Probably for some time. No burned smell etc. I can touch and hold it. Any ideas? The wires to the alternator are not hot at all.

On the ecu I have given the 5 earths their own connection to chassis earth. When I sort out the alternator, I will connect the led and get it flashing correctly and then add in the bits to the ecu one by one untill I find what is causing the irregular flash of the led.

This is so time consuming! If I could afford i I would buy an ME221 sorted with loom for the st170. Second hand would be good.

big_wasa - 12/7/18 at 07:18 PM

I do get it that not every one loves the electrics and this is really is the more you make the less it cost ethos.

Re the Me221, It wonít stop with the ecu as chances are you will be doubling up by the time itís mapped.

You have u2u

Pigsy - 12/7/18 at 08:14 PM

I forgot about the setup fees. Thanks for your definite help.. Any ideas on the alternator? It is connected with the smart start and I bought a proper battery just to get it right, but its got lost in the post! I had no battery drain until recently. Thats only just started. I will google how to trace it.

On the good side:
The led with pats was working until recently and the fuel pump is priming.

big_wasa - 12/7/18 at 08:38 PM

Start by unplugging it.

Iíve said a few times you can get it running on the basics and add in stuff as you go.

Pigsy - 12/7/18 at 09:43 PM

Thanks. You have. When the led was flashing correctly it still ha no spark. Then I discovered that there was no 12v to the coil centre wire.. Still no spark. What would you have done next please?

Pigsy - 12/7/18 at 09:44 PM

That was while I had the power charging on.

Pigsy - 16/7/18 at 06:01 PM

The alternator is fixed now. I have spent the afternoon stripping the ecu of all wires from the loom to get back to basics. I am fitting a new power supply from the battery, both being switched and un-switched. Relays work on both. I have fitted a new 12gang fuse box and wired it in for both switched and un-switched.The wiring for the engine and fuel pump will be totally separate from the MG loom this way. So far the LED is not doing what it should, but I may have removed a pats wire doing it. Will it harm having the sensors connected? I can always cut the ecu plug wires and rejoin them.

FamilyGuy - 17/7/18 at 05:40 PM

Finally got her fired up
Only for a short blast as no coolant plumbed in yet. Get that sorted then I can test it properly. Still need to finish off and tidy up the wiring but at least it works. This threads been a great help.
The idle seems high, not sure if that's due to no clutch position switch fitted?

Pigsy - 17/7/18 at 05:49 PM

Oh very well done. It must feel good!!!!

FamilyGuy - 17/7/18 at 06:14 PM

It was a very good feeling... and a ray of hope for all other electrical novices

Need to get it running with coolant plumbed in and try to get my obd dongle linked up to the ecu / phone properly to check for any issues but I'm just chuffed I'm off the starting blocks!

big_wasa - 17/7/18 at 06:49 PM

Well done.

One of the load switches needs earthing, I think itís the clutch switch but I would have to check. Also every time you disconnect the memory from ecu it has to re learn fuel trims and bits and does give a height idle for a minuet or two.

big_wasa - 17/7/18 at 06:58 PM

Originally posted by Pigsy
The alternator is fixed now. I have spent the afternoon stripping the ecu of all wires from the loom to get back to basics. I am fitting a new power supply from the battery, both being switched and un-switched. Relays work on both. I have fitted a new 12gang fuse box and wired it in for both switched and un-switched.The wiring for the engine and fuel pump will be totally separate from the MG loom this way. So far the LED is not doing what it should, but I may have removed a pats wire doing it. Will it harm having the sensors connected? I can always cut the ecu plug wires and rejoin them.

Triggering the Immobilizer wonít damage anything.

Pigsy - 17/7/18 at 10:03 PM

Thanks. Instead of cutting and joking wire I will simply unplug cable from sensor.

FamilyGuy - 18/7/18 at 04:07 PM

Originally posted by big_wasa
Well done.

One of the load switches needs earthing, I think itís the clutch switch but I would have to check. Also every time you disconnect the memory from ecu it has to re learn fuel trims and bits and does give a height idle for a minuet or two.

Do you simply leave the switch out and earth the wire?

big_wasa - 18/7/18 at 04:23 PM

I am sure the clutch is a normally closed switch but let me check my notes first.

[Edited on 18/7/18 by big_wasa]

FamilyGuy - 23/7/18 at 08:36 AM

I've had a look at the ford wiring diagram and it looks like the clutch switch is normally open, closed when clutch is depressed. Is it therefore a good idea to fit the switch or would it serve no purpose?
I guess I could see how it goes without it and take it from there.

FamilyGuy - 23/7/18 at 09:08 AM

Still haven't been able to get my OBD dongle to connect to the engine. I have all pins connected as per your diagram but I don't currently have pin 7 on the port connected. It looks like you have this connected to ecu 13 shared with OBD pin 13. Does that sound right? I've checked my dongle on my daily driver and it works fine so I can only assume I've done something wrong with my wiring.

big_wasa - 23/7/18 at 10:53 AM

Originally posted by FamilyGuy
I've had a look at the ford wiring diagram and it looks like the clutch switch is normally open, closed when clutch is depressed. Is it therefore a good idea to fit the switch or would it serve no purpose?
I guess I could see how it goes without it and take it from there.

I will have a look but there is one load switch that is normally open.

big_wasa - 23/7/18 at 11:01 AM

Originally posted by FamilyGuy
Still haven't been able to get my OBD dongle to connect to the engine. I have all pins connected as per your diagram but I don't currently have pin 7 on the port connected. It looks like you have this connected to ecu 13 shared with OBD pin 13. Does that sound right? I've checked my dongle on my daily driver and it works fine so I can only assume I've done something wrong with my wiring.

The diagram I am sure is correct and the legend wrong. I am sure the engine does not use pin 7.

Again depending how hot and bothered i am after work and what jobs her indoors has got for me to. I will have a look.

[Edited on 23/7/18 by big_wasa]

FamilyGuy - 23/7/18 at 01:51 PM

Thanks. Appreciate the help when you get a minute.

big_wasa - 23/7/18 at 06:02 PM

No pin 7.

This is my test rig and Iíve used this to program the ecu and all sorts.

You are correct, the clutch switch is normally open so you can just remove the pin.

The power steering switch is the one normally closed so is the one to earth.

Pigsy - 23/7/18 at 10:17 PM

Hi. I have wired in the key and circular ring with its 4 wires as per your diagram you kindly sent. I have a spare uncut loom plug which I have fitted to the ecu away from the car. So I have the key setup fitted to the plug with the pats led and all pats connections as per your diagram. No other connections apart from power supply to 55KAM and the earths (not common brown) connected. There is a fast flashing of the led. (Itís not a flashing type of led.) When I switch on 12v to pin 71 via a 30amp relay it stops momentarily and then flashes again at the same rapid speed.

Could the key and transponder be faulty?
Could the ECU be faulty?
Is it something I have missed in the wiring?

If you think that you have the answer please just say.

Pigsy - 23/7/18 at 10:20 PM

For transponder please read transceiver or aerial with key. Any way of testing it?

big_wasa - 24/7/18 at 07:20 AM

You don't say if your powering up the ecu at the same time.

Black top and silver top transceivers work on different frequencies and are not interchangeable.

I sent you a message that looks like you have not read offering to have a quick look over your loom and test the key is matched to your ecu. Unfortunately I don't have time to build you a one off loom.

No charge, you just need to sort postage both ways

Cheers Warren

Pigsy - 24/7/18 at 11:03 AM

I have this wrong somewhere. With the 12v supply to ecu pin 55KAM already live, the way to power up the ecu is to switch on 12v to pin 71 via a 30amp relay. Is this right?
Please donít worry if you are too busy to look over my loom Warren. I am making a silly mistake somewhere, but I will get there.

big_wasa - 24/7/18 at 11:29 AM

71 + 97 there are two.

Pigsy - 24/7/18 at 05:35 PM

Thanks big-wasa. I have actually got 97 switched as well. Just forgot to write it down (a lot of juggling of time at the moment).

I have a Ford Focus ST170 ECU, key and key sender from 2002 to match the engine on the way from a car with absolutely no electrical faults. Its the same year as my engine. It is in case I was sold a mismatched key setup and ecu. I wish I had just bought a donor car to begin with.

big_wasa - 24/7/18 at 06:17 PM

2002 to 2005 I think there is two software codes but itís all the same wiring

Pigsy - 24/7/18 at 09:50 PM

Great. Any items purchased on eBay for my year st indicate 98-2004. Why goodness only knows. Iím pleased you know though.
Mines the Alda engine.

big_wasa - 25/7/18 at 09:50 AM

Standard mk1 focus manufacturing years are 98~2004. St170 is 2002~2004 but for second hand spares there where cars registered 2005.

FamilyGuy - 25/7/18 at 09:52 PM

Originally posted by big_wasa
No pin 7.

This is my test rig and Iíve used this to program the ecu and all sorts.

You are correct, the clutch switch is normally open so you can just remove the pin.

The power steering switch is the one normally closed so is the one to earth.

Hmm, I seem to have fewer wires connected than you, but my OBD port is as it was in the focus. I had all wires below connected with the exception of pin 7

big_wasa - 26/7/18 at 05:17 AM

St170 has two more wires than the base model as it has canbus.

They also may use different pins for different modules ie pin 7 is the K line and according to the ford diagrams may be used for the telemetrix.

Pigsy - 26/7/18 at 07:58 AM

Hi. Where did you find your ford diagram?

big_wasa - 26/7/18 at 11:37 AM

Somebody posted them on this link.

Pigsy - 26/7/18 at 06:31 PM

Big_Wasa, the image supplied for connecting the led to ecu, has the ecu as a 6MYD (Focus Rs mk1), using pins 53, 19 and 42. It also has the aerial connectors 1-4.

Is it the same way of connecting as with the 3NFA for the ST170? It also has the aerial connectors 1-4, so would these be the same?

Im starting again with the newer ecu, key and aerial, that should arrive tomorrow. I'm also checking for any mistakes as I reconnect.

big_wasa - 26/7/18 at 07:05 PM

Yeh itís the same.

FamilyGuy - 26/7/18 at 09:13 PM

Originally posted by big_wasa
St170 has two more wires than the base model as it has canbus.

They also may use different pins for different modules ie pin 7 is the K line and according to the ford diagrams may be used for the telemetrix.

Looks like I'm missing pins 6 and 14. Wondering how it ever worked in the focus as I haven't removed any wires when I took it out the car. Need to find an extra pin for the missing wires now

big_wasa - 27/7/18 at 05:21 AM

They are the can bus pins. You're obd2 should still communicate on the other data platform.

Pigsy - 30/7/18 at 06:22 PM

Hi. I have at last got the led to flash correctly, then disappear when the relay to the switched items is powered up. It is a great feeling. The problem has been that the key was not matched to the ecu. It is now the third one that I have tried and it has brought success.

I have subsequently wired up the various component sensors needed like fuel injection, the fuel pump which is priming nicely, the cam and crank sensors, tps, imrc, and many others and the led is is still fine.

My problem is that I have no spark. I have 12v to the 3 pin plug on the coil, apart from that, can you think of what the likely cause is? All suggestions will be helpful.

FamilyGuy - 30/7/18 at 08:35 PM

Might sound obvious but have you got the engine block earthed?

Only thing I can think of if all wires to coil and other sensors are properly wired up.

Pigsy - 30/7/18 at 09:52 PM

Very well earthed in two places and across the gearbox as well. I will double check the wires to the coil as well. Thanks for replying.

Pigsy - 30/7/18 at 09:57 PM

Im setting up forscan with a switched elm 327 obd2 reader via laptop. It may say what is wrong.

big_wasa - 31/7/18 at 07:39 AM

The ecu will only fire the plugs if it knows the engine is cranking.
More important than a code, look at live data to show the ecu is seeing the sensor. Ie your looking for an rpm signal.

This plug is polarity sensitive check its wiring is the correct way around. All st170's where manual gearboxes but is there any possibility the crank sensor housing has been swapped for an automatic ?

Pigsy - 31/7/18 at 10:23 AM

I swapped the sensor to the front with a missing tooth setup. I will check itís polarity.

big_wasa - 31/7/18 at 10:51 AM

Sounds like this will be your problem. Chances are its to far away, to near and its damaged.

Pigsy - 31/7/18 at 02:26 PM

The three wires to the coil are two earths and a centre power supply. Anyone know itís voltage please? Is the coil wired to the ecu or ignition switch?

From what I have read, it is either 5v or 12v or wait for it: actually both 5v and 12v at the same time, which it cannot be!

FamilyGuy - 31/7/18 at 03:53 PM

It's a 12v supply. I have mine connected to the power relay output. If you are not using a power relay it would connect straight to ignition switch or whatever switch you were using to power the engine up.

daviep - 31/7/18 at 05:16 PM

Originally posted by Pigsy
The three wires to the coil are two earths and a centre power supply. Anyone know itís voltage please? Is the coil wired to the ecu or ignition switch?

From what I have read, it is either 5v or 12v or wait for it: actually both 5v and 12v at the same time, which it cannot be!

Not familiar with your particular setup but normally the coil is supplied with positive and the ecu switches the negative side of each coil. When the current stops flowing the electromagnetic field in the generated by the primary coils collapses and induces a voltage on the secondary winding causing a spark. If you don't have the negatives wired to the ecu you won't get a spark.

Or that's how I understand it works.


Pigsy - 31/7/18 at 08:49 PM

you guys are so helpful. Thanks for that.

Pigsy - 8/8/18 at 10:00 PM

I actually got it going today!!!!!!!!!!!!!!!!!
This is a very large thanks to all who helped me to do so.

I have discovered that the intake valves are not sealing. Piston 3 just exhaling everything out of the gsxr750 no3 inlet. Nightmare. Anyone know of any problems associated with the 2002 st170 head that would cause this?

Thanks again........

rusty nuts - 9/8/18 at 07:01 AM

If the valves are not sealing there are a few possibilities, burnt valves/seats , damaged cylinder head ,, bent valves , sticking valves, , valve being held open due to incorrect valve clearances, valve seat recession (unlikely) or as I had a few years ago a floating valve guide again unlikely. Incorrect valve timing I would expect to affect all cylinders. I would start by checking the valve clearances especially if the cams have been out . An exhaust valve not opening can cause spitting back through the inlet but I haven't come across that for many years.

Pigsy - 9/8/18 at 10:41 PM

2 bent inlet valves. :-(

rusty nuts - 10/8/18 at 07:05 AM

I would remove all valves , clean ,check seats and if needed relap before reassembly . Don't forget to check and adjust the valve clearances . Wonder why only two bent valves ?

FamilyGuy - 10/8/18 at 03:22 PM

Glad you got it started, must have been a relief. Shame you've unearthed another problem.

[Edited on 10/8/18 by FamilyGuy]

Pigsy - 11/8/18 at 12:24 AM

Itís not pleasant, but then itís ok. Mighty relieved it ran at all. Thanks for your needed help.

I donít know if anyone has had this but without a car reg or vin number, motor factors are useless! I had the Alda engine head and block numbers but even though they saw them on the screen, would not sell the valves to me.

I just looked up a 2002 focus st170 for sale on eBay and used itís registration number. Worked a treat. None in stock. I will get them tomorrow morning. Guess what Iím up to tomorrow?

Pigsy - 12/8/18 at 11:06 PM

Itís all done. Iíve fitted a reverse water pump impeller. Sorting its mount and belt.

big_wasa - 13/8/18 at 05:22 AM

So it's now running ?

Pigsy - 13/8/18 at 06:48 AM

I have had it running yes thanks. All is working but i need the aux belt to give it a proper run with the water pump pumping. Your list here is invaluable. It has been very helpful. The thing that I did not understand with the wiring is that the voltage goes to the various sensors and then back to the ecu which times their use by being an earth switch. I had thought that the ecu put out the voltages to the sensors when it is the other way around. Probably technically wrongly worded, but I have a simple mind. Thanks again to all who helped me.

FamilyGuy - 15/8/18 at 04:45 PM

Can the cooling fan be switched off the ecu pin 68 or do you need a seperate coolant temperature sensor/switch. It makes sense to use the ecu to control the fan if possible but I don't understand why they would have a seperate switch for the fan mounted in the radiator on the st170.

I stupidly cut off the ecu wire for the power steering load switch input right at the connector. I now need to remove the ecu pin so I can connect it to the earth. I think I've done the same with the evap solenoid pin so will need to sort that one as well.

big_wasa - 15/8/18 at 06:09 PM

You can switch it from the ecu or from a switch in the top hose / rad. You will want the relay from the donor as it has a diode in it or somthing. I tried with a standard relay and it just would not have.

You want the fast fan pin.

The st170 switch doesnít actually fit in the rad, they clip it to the back of the battery tray. Itís wired perm live so it will over run with the ignition of.

FamilyGuy - 16/8/18 at 04:09 PM

I have all of the relays off the focus still so I will have to try and identify the cooling fan relay. So I will need to wire the control side of this relay up to ecu pin 17 and the power relay output (for my setup), and the load side up permanent live and earth. No need for the additional coolant temp switch and the ecu which has permanent live supply will control the over run. Am I thinking along the right lines?


big_wasa - 16/8/18 at 04:48 PM

Yeh itís a green 5 pin relay. The 5th pin is an extra chassis earth

big_wasa - 16/8/18 at 05:19 PM

I may have told you wrong there.

I think itís pin 68 Black/blue.

Relay PIN numbers.

1) green/blue this is switched live.
2) Black/blue this is the ecu switched earth.
3) Red this is permanent live.
5) this is to the fan motor via a 30a fuse.
7) this is chassis earth.

You need to keep a very close eye on it until your happy it works as it doesnít kick in until 113 deg and off around 98.

But it works, my turbo Zetec will sit there and cut in and out all day long.

FamilyGuy - 16/8/18 at 09:52 PM

Thanks for info, I'll give it a go.

The only thing I planned on doing differently to what you have stated above is to fuse the live feed to pin 3 of the relay and not to the fan motor. I can't see any issues with this as it is protecting the same circuit but please do tell me if I'm missing something though.

big_wasa - 17/8/18 at 05:08 AM

To be honest I would probably do the same. The above is just how it is in the Focus.

Chris1982 - 20/8/18 at 10:10 PM

Is this still alive post I am new to this site and need help

big_wasa - 21/8/18 at 05:13 AM

Yeh I am still here.

Pigsy - 21/8/18 at 04:40 PM

i. If ecu 56 black/blueóevap pin 2, is the pin 1 to live 12v or earth please?

Pigsy - 21/8/18 at 04:44 PM

if 83 green/yellow -- idle air control valve pin 2, is the pin one 12v please?

big_wasa - 21/8/18 at 04:45 PM

12v the ecu switches the earth.

big_wasa - 21/8/18 at 05:09 PM

Originally posted by Pigsy
if 83 green/yellow -- idle air control valve pin 2, is the pin one 12v please?

You have found an error in my pin outs. Pin 83 should be black/yellow as per the plug, green/yellow is the switched live side of the solenoid.

The ecu switches the earth side of the circuit.

big_wasa - 21/8/18 at 05:11 PM

Pin 1 is the power and pin 2 the earth.

Pigsy - 22/8/18 at 06:56 AM


Pigsy - 25/8/18 at 06:15 PM

ecu pin 67 Evap canister vent control Bk/Og,
ecu pin 56 Evap purge solenoid valve Bk/Blu.

As far as I'm aware (no doubt wrong), they are wired as above. I have the ecu pin 67 Evap canister vent control Bk/Og with connection plug pin1 being Gn/Red.

As for ecu pin 56 Evap purge solenoid valve Bk/Blu, with what and how is this wired.

your help will be appreciated.

big_wasa - 25/8/18 at 07:10 PM

There is no pin 67 ?

There is only one canister purge valve. It has a live and the ecu switches the earth.

Pigsy - 26/8/18 at 09:26 PM


Pigsy - 30/8/18 at 09:30 PM

I have the st 170 ecu completely wired in now.Problem: while it starts and fires easily, it idles way too fast. About 2700 rpm. I have fitted the GSXR 750 injection bodies, using the standard injectors and rail, the standard air idle control by using a small bore (+/- 4mm) 4 port manifold that has 4 pipes inserted into the throttle bodies inlet manifold side of the butterflies. From this little manifold, one larger tube runs to one of the air idle controls ports. The second port next to it runs a tube into an air filter.

It is the same as this Google image:

I have blocked any possible air leaks including around the injectors with a silicone sealant for car engines.

Can anyone think of a solution please?

big_wasa - 31/8/18 at 07:44 AM

Remove the idle control valve. You won't need it on the bike itbs as they will be set up for idle on the screws. And 're check for air leaks. You will also need to balance the itbs.

Pigsy - 31/8/18 at 05:57 PM

Thanks. I will check again and run it without the idle valve.
The itb's are already balanced and barely open.

Will the ecu not control the idle anyway using fuel enrichment?

What about a choke?
I have a manual choke setup and it makes no difference at all. I disconnected it but can easily reconnect it.

Pigsy - 8/9/18 at 07:20 AM

Any suggestions on a rev counter connection. Connects as a Smiths modern type. From coil pin 26 or 52? Needs 12v negative earth.

big_wasa - 8/9/18 at 10:38 AM

Is the tacho adjustable for cylinder count ? Due to the wasted spark system of the Ford you have to adjust the cylinder count to compensate.

Pre CAN ecuís had a dedicated tacho out put that I used, but for my new install I am looking at a full can dash with all data coming from the Ecu.

So having swerved your question, you will have to try it and see as I havnt done it. But please let us know in case I change my mind and go the Etb telemetrix again as I did love the classic look.


Pigsy - 8/9/18 at 09:42 PM

Not adjustable for cylinder count. There are devices out there to do it as well as circuit diagrams to make one, all driven by the coil. watch this space.

Pigsy - 8/9/18 at 09:49 PM

Pigsy - 8/9/18 at 09:50 PM

Pigsy - 14/9/18 at 04:32 PM

Hi. My build starts easily BUT runs very poorly and backfires. I have traced all the wires and see no mistakes. Obd2 reader tells me that the o2 sensors have a fault. They are brand new and the wiring is correct. It says the same for the maf sensor. It is also brand new. I noticed that the earth had become dislodged and so reconnected it. It then would not start. I had to disconnect it again. Is there a trick method for doing away with it? It was idling way too fast but is ok now. When I open the Suzuki gsxr750 throttle itbís it wants to stall. Has anyone any suggestions to overcome these problems.

Iím close to removing the itbís and refitting the standard inlet system with its sensors etc as this is proving to be very difficult to do not to mention time consuming. I would rather not as they add horses and sound great. Has anyone seen a blog on an st170 with bike carbs and original ecm/ecu please?

big_wasa - 14/9/18 at 04:43 PM

They wonít add any horses due to the mapping.

Multi sensor failure will be a power or earth fault.

Pigsy - 14/9/18 at 09:39 PM

Thanks again.

FamilyGuy - 5/11/18 at 09:43 PM

Can the temp sensor from the st170 thermostat housing be wired in to an acewell dash unit?

I'm wanting to avoid having to mount an additional sensor in the hose if possible.

Any advice appreciated.

big_wasa - 6/11/18 at 06:42 AM

No the Acwell will need its own matched sensor. If its a single wire sensor you will need to work out a way of earthing it if you screw it into a plastic housing.

FamilyGuy - 6/11/18 at 04:39 PM

Thanks. I'll just mount the acewell sensor in the hose after the stat.