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Tin-Top issues.....
mcerd1 - 11/7/17 at 12:28 PM

My tin-top has suddenly developed a bit of an issue were the ABS & traction control lights are randomly coming on, staying on for a bit and then cancelling themselves also the speedo is occasionally 'jumping' by anything up to 10mph above the actual speed for a split second (even when the car is parked with the engine off) - which I suspect is the cause of the ABS/TC light
but now it also appears to have developed a random misfire / hesitation thats only really noticeable when cruising at a steady speed (not sure if this could also be related to the speedo issue or not ? )

I get a warning light that suggests its got a code, but nothing comes up on my OBD tool (doesn't do ABS codes, but no engine codes are pending either)

until now I've had no significant issues with the thing except for a sticky rear caliper that was getting a rather hot - so I was wondering if it might of cooked the sensor - but should this affect the speedo ?


Anyone got any other ideas ? - otherwise I might have to bite the bullet and ask the garage to look at it
The car is an 2008 C-max with the 1.8 duratec


cheers
-Robert


Nickp - 11/7/17 at 01:06 PM

Same here, our lasses 06 Ibiza has had the ASC / ABS light on since the weekend. My OBD reader has the same limitations and only reads engine codes. A mate is fetching his whizzy Snap-on one round which I suspect will find a dodgy wheel sensor.


Ben_Copeland - 11/7/17 at 02:23 PM

Usually an ABS sensor on one of the wheels, it'll be controlled by the ECU but the signal will come from one of the wheels.

Google will help to find which wheel tells the ECU the speed and start from there.

Or find a helpful independent garage that'll scan your ABS system for you and that should tell you which sensor or ECU


britishtrident - 11/7/17 at 02:29 PM

The speedo fluctuation might be a clue on most cars the speedometer is only driven by only one of the abs wheel sensors --- usually a front, you can tell which by jacking up one front wheel at a time a observing which activates the speedo.

But if it were me I wouldn't waste my time trying to chase it down without ether a scan tool that reads codes or an oscilloscope to check each wheel signal in turn.
In the old days ten minutes doing a visual inspection of the toothed rings and a voltmeter check on the signal output of eath wheel would located any ABS fault.
Modern ABS systems aren't as easy to diagnose as the early systems, modern system have active hall effect sensors and the magnetic ring is part of the wheel bearing oil seal and can't be visually inspected. As result unless you know what corner the fault is on you end up playing sensor and wheel bearing roulette which can get very expensve.

For diagnostics try the FORScan program Link to FORscan web site together with THIS or you could buy a scantool made by Autel or Launch or Foxwell that covers Ford ABS


nick205 - 11/7/17 at 04:01 PM

SWMBO's 2007 VW Touran had the ESP light come on and stay on a few weeks ago. Some Googling suggested it was a relatively common VAG fault related to sensors on the steering column. Suggested solution was turn the steering wheel fully left then fully right with the engine off. The turn the engine on - should reset the sensors. Seemed to work and ESP light now works as it should with the switch by the gear stick.

Yours sounds sensor related to me as well. The posher Snap On reader might pick it up. Otherwise a garage with higher level diagnostic reading capability might be the answer.


Nathsx - 11/7/17 at 07:50 PM

Water ingress ??


hearbear - 11/7/17 at 10:52 PM

Check you haven't got a worn front wheel bearing mine has a bit in it and brings the abs light on and then goes off after a bit. Just another job to do.


roadrunner - 12/7/17 at 10:35 AM

Second the water ingress. Or a dodgy earth.


DW100 - 12/7/17 at 06:04 PM

My leg hurts and I googled it, apparently the most likely cause is a shark has bitten it off. Funny as I haven't been near any water recently.

[Edited on 12/7/17 by DW100]