Board logo

VAG specific car / mechanical / electric advice needed for daily VW Passat 2007 hand brake
Steve Hignett - 10/9/17 at 02:38 PM

Hi All,

I've not been on the forum for some time, but I have a problem with my wife's car that google isn't giving me answers on, so am hoping someone will have some experience with on here enough to offer some advice...

I bought my wife a high mileage Passat Estate from eBay, quite cheaply. It has the 1.9 TDi 100ish bhp engine, so I knew that apart from being gutless, the engine shouldn't give me too much grief.

I think it has a couple electrical gremlins that could be the source of my problems, but what happened was;-

Picked the car up, EPB was fine for a few days. Then started being a little temperamental, but only for a day or so before I took it to get four tyres fitted and it seized on, on the ramp. The garage owner (ham-fistedly) smacked the button a gazillion times to no effect. One of the mechanics wound the passenger side caliper in (only one was stuck) and that was that.

I haven't had time to look at it in weeks, however I did take the EPB motor off the back of that caliper, chucked a load of WD40 in it and put 12v to the terminals moving it clockwise and anticlockwise relatively smoothly.

There was absolutely nothing from the switch. Just flashing warning in the dash and switch.

A switch is only a tenner so I replaced that, knowing it was unlikely to fix it, but it was easy and cheap, so worth a go, bit no luck..

Cut to today. Just removed all of centre console to get to the EPB module. Replaced it with a similar age one (but different codes on it), re connected the battery, tried it and it engaged.
Tried button again, and disengaged. Happy days - one more time and there was nothing again.

I'm thinking for it to go in this way it can only be a couple of things;
Dodgy wiring
Or
The caliper motors are stuck in some position and that's over stressing the module in some way and making it fail or cut out.

They're my two guesses, but I know nothing about this age of VAG cars and am about as far from a mechanic as is humanly possible.

So, if anyone has any suggestion, please post them up on here.
Alternately, if anyone is happy for me to give them a call and talk through exaxt ly what I've done properly and offer any advice, then please inbox me your number and I'll call when its convenient for you...

As always, thanks in advance for any help you can give..

Thanks,
Steve

[Edited on 10/9/17 by Steve Hignett]


gremlin1234 - 10/9/17 at 03:04 PM

searching for "VW Passat 2007 hand brake" found many articals.
in particular
this long thread
https://www.whatdotheyknow.com/request/vw_passat_electronic_paking_brak

which also has a link to how to reset the module
http://nateronline.com/Technical_Bulletins/2008.07.31_Elec_Brake_doesnt_respond_warn_light_on.pdf


britishtrident - 10/9/17 at 03:06 PM

While it is likely it is a caliper issue to diagnose it properly you need to use a scantool that will communicate by-directionally with the EPB such as Autel Mxidiag Elite MD802 or Autel Diaglink

[Edited on 10/9/17 by britishtrident]


obfripper - 10/9/17 at 08:33 PM

Replacing the epb module requires coding to the vehicle, the coding can depend upon the part number, so your original coding may not be correct for a replacement module.
The module will not work correctly unless the coding matches the equipment level of the vehicle, this could be anything from just illuminating the epb fault light to the handbrake not working at all.

Quite often the calipers will work when operated after the car has stood long enough for the control units to go into standby, this may only be for 1-2 cycles before the system locks up again.

The calipers require basic settings to be carried out before they will operate correctly if they have been manually wound back, your original problem may be cracked plastic casings and water ingress due to the cracks - this may require new calipers and the loom repairing (due to water ingress) before basic settings will work.
I have also had epb modules fail due to overcurrent caused by a faulty caliper overloading the control unit, this results in an inability to carry out basic settings even when the wiring is repaired and faulty caliper(s) replaced.

The switches do play up, there is a modified switch that may need a software update for some older cars to work correctly (there is a different internal wiring for the modified switch).

The first thing is to get a code scan done of the epb system to establish what is at fault, with the original control unit fitted, then clear codes and rescan to see what reocccurs (there may be some codes that have been introduced due to swapping modules about, not necessarily originating from the epb module - the abs, engine management, transmission can all leave codes here)

Also have a look here for a manual reset for the switch - this tsb is for usa market vehicles which have differing epb software so may not work as described.
http://nateronline.com/Technical_Bulletins/2008.07.31_Elec_Brake_doesnt_respond_warn_light_on.pdf

Here are a good deal of the procedures possible with vag-com (now known as VCDS) along with the prerequisites for replacing/coding a replacement module.
http://wiki.ross-tech.com/wiki/index.php/VW_Passat_%283C%29_Parking_Brake

Dave


Steve Hignett - 11/9/17 at 09:02 AM

Quick update.

I now have a copy of VAGCom and a lead that I hope is correct for the car.
So, will need to install it to the laptop and give it a go. I've never used it before. And its cheap one from eBay, so hope it works as it should.

I probably won't get round to looking at it before the weekend...

As for the other suggestions, thanks very much!

I'm pretty sure that the caliper, or rather the motor behind the caliper, isn't stuck in due to water ingress. Its one of the solutions google has suggested that I checked.

What I find most bizarre is that the EPB worked fine two or three times, both to engage and disengage when I fitted the replacement module, but then failed again.

Surely, if the problem was located at the caliper, being seized etc, it wouldn't have worked at all, or continued to work.

Is it easy enough to check that I'm getting a signal to the caliper?
Is it just a case of seeing if 12v +ve & 12v -ve is going to the motor at the rear?

I knew that replacing the module could easily cause issues, but as above, it should either work or not work???

To make matters work, I damaged the ESP switch near the gear lever in the process, so now that's another light on the dash!

Oh, I also forgot to mention that the MOT is due soon, too!!


Thanks,
Steve


nick205 - 11/9/17 at 09:11 AM

I had 2 2007 Passat estates (B6 model), both with EPBs. Changing the rear brake pads apparently required the car to be connected to diagnostic type software so the rear calipers were reset in the correct position. Something I found annoying as I'm ordinarily quite happy replacing discs and pads myself.

I used a local independent VAG specialist with the right software for the work. For you it may be worth finding a similar independent specialist to check/reset the system.

I have heard of people having to replace the switch before - never suffered this myself though!

[Edited on 11/9/17 by nick205]


SJ - 11/9/17 at 09:39 AM

quote:

I had 2 2007 Passat estates (B6 model), both with EPBs. Changing the rear brake pads apparently required the car to be connected to diagnostic type software so the rear calipers were reset in the correct position. Something I found annoying as I'm ordinarily quite happy replacing discs and pads myself.



That's just bonkers.


nick205 - 11/9/17 at 11:10 AM

quote:
Originally posted by SJ
quote:

I had 2 2007 Passat estates (B6 model), both with EPBs. Changing the rear brake pads apparently required the car to be connected to diagnostic type software so the rear calipers were reset in the correct position. Something I found annoying as I'm ordinarily quite happy replacing discs and pads myself.



That's just bonkers.



I agree - I did spend some time trying to find a way around it, but couldn't!

Perhaps VAG trying to protect some revenue on their cars?


mcerd1 - 11/9/17 at 12:15 PM

^^ one of the guys I work with had the same car with the same issues

towards the end him and his VAG specialist mechanic mate had replaced the calipers, button - then fully tested the control unit and even rewired all the connections to the calipers (it had rubbed though wires that a garage had 'fixed' in the cars past, but they were cross wired on one side) - and they still didn't want to work properly...

in the end he scrapped it and got a focus with rear drum brakes and a manual handbrake leaver


I've heard stories of the alloy caliper housing corroding such that the waterproof seals on the motors get damaged, then its only a mater of time before it dies - but they aren't cheap parts and its still not guaranteed to work


you can convert these cars to use manual handbrake lever though
one version uses the calipers, lever and centre console from the base model version, another uses the parts from the previous generation of Passat


[Edited on 11/9/2017 by mcerd1]


britishtrident - 11/9/17 at 12:18 PM

quote:
Originally posted by SJ
quote:

I had 2 2007 Passat estates (B6 model), both with EPBs. Changing the rear brake pads apparently required the car to be connected to diagnostic type software so the rear calipers were reset in the correct position. Something I found annoying as I'm ordinarily quite happy replacing discs and pads myself.



That's just bonkers.


All modern cars are like that it isn't a show stopper you just need the right scantool to talk to the system, VAG were early adopters but the car world has change all the systems on modern cars are controlled by intelligent local modules. Scantools that talk bidirectionally systems have become a lot cheaper and are a must have if you want to do even simple jobs like change brake pads or njectors or light switches.


SJ - 11/9/17 at 01:11 PM

quote:

quote:
Originally posted by SJ
quote:

I had 2 2007 Passat estates (B6 model), both with EPBs. Changing the rear brake pads apparently required the car to be connected to diagnostic type software so the rear calipers were reset in the correct position. Something I found annoying as I'm ordinarily quite happy replacing discs and pads myself.


That's just bonkers.


All modern cars are like that it isn't a show stopper you just need the right scantool to talk to the system, VAG were early adopters but the car world has change all the systems on modern cars are controlled by intelligent local modules. Scantools that talk bidirectionally systems have become a lot cheaper and are a must have if you want to do even simple jobs like change brake pads or njectors or light switches.




Interesting. I might need to look into scan tools as my new Mazda has a electrical handbrake. I still haven't fully come to terms with CANBUS!


obfripper - 11/9/17 at 01:20 PM

The epb system is very picky over poor connections, i have had several where the plug/connector looked fine but would not work. Sometimes a spray of contact cleaner and disconnecting/reconnecting 20-30 times followed by clearing any residue with more contact cleaner then compressed air to dry can bring back functionality.
I have had the water also travel back through the loom and corrode the wiring inside the insulation, this can be a pain to trace how much to cut back and repair or whether to just replace with new.
Codes 02432 & 02433 are the usual ones where there is a circuit fault, there is also a software update that can reduce the likelyhood of these codes being set for a erroneous poor connection.

If the codes are just basic setting related, use vag-com, and proceed as if you are going to change the rear pads, if there is an electrical malfunction the faulty caliper will not retract.
If you hear both caliper motors winding back, then 30 seconds after they stop operating, click on the close caliper function, allow this to complete and then wait 30 secs.
Hold down the footbrake and press the handbrake button , and the handbrake should release - at this point the caliper basic settings will have been set and the yellow epb lamp should go out.
There are other settings that can be calibrated, but if you have gone back to your original control unit these should not be neccesary.

Dave


Steve Hignett - 3/7/18 at 07:23 PM

Hello Dave and other helpful suggestion type people!

So, I know I should have sorted this problem (now should read as THESE problems) out by now, but losing job last year and starting somewhere else on less money, and not managing to get the vag-com working at all have made me ignorant and lazy to the point that I have left them all this time...

Now, the starter motor is playing up...

I'm going to sort the starter motor next weekend, and a friendly mechanic (using basic software) has scanned the car, but could not reset some of the codes.

Before he scanned it, I did replace the module back for the original one..

Please see below for a photo of the scanned faults including the ones he wasn't able to reset. So this is how the car is at the moment...



Apologies, I'm struggling to upload the photo from my phone. Will do it via laptop shortly if I'm able too..


Steve Hignett - 3/7/18 at 07:35 PM



Steve Hignett - 3/7/18 at 07:36 PM

I have uploaded photo above, but it doesn't appear very big.

(it's been a while since I've had a kitcar, so not fully up to date with the site's settings..)