Post 36455 » Re: ABS Warning Light » Peugeot Central

Posted: Thu 08 Oct, 2009 4:41 pm

Hi all, i bought a 307 bout 5 month ago, lovely car to drive not a problem with it untill this week. I was doin my usual trips and the ABS light come on the car meaning there was a fault and i had no ABS brakes. Anyways i stopped the car pulled over and had a quick check, nothing found. Turned the car back on and the ABS light went off hmmm. anyways left it for that day. next day did the same. took it to my local garage were i always go they ran the diagnostic test on it come up as the left rear ABS was faulty. The garage stripped it down and nothin wrong the rear ABS sensor they stripped all 4 down and found the drivers side front wheel the bearing was knackered on it, they swapped it. rang me up and said the car was done and ready. went and picked it up drove bout 3 mile then the light came back on. The garage have stripped everything down around the sensors and found nothing. when the light come back on they put it back on the diagnostic stick and this time they said it was the rear right sensor this time but as i said they manually checked it and nothing wrong with it. they did a road test with the diagnostic test still running while the car was in motion and they tested it all and the results all come back sayin the car was in working order :/ anyone any ideas about this or have heard this problem before ?

thanks mike

Posted: Thu 08 Oct, 2009 4:54 pm

How do they 'manually' test it?

They need to do either :
a) look at live data from the four wheel sensors on a road test
b) Use a scope (better method) to look at the output from the sensors.

What was the actual fault code(s)?
I'm thinking it will be a coherence fault.

Posted: Thu 08 Oct, 2009 4:57 pm

Hi

Do you know what the fault was?? was it a coherence fault? Ive had quite a few 307 with this , and found that either dirt ( metal fillings) were inhibiting the rear sensor , or the gap between the sensor and the bearing was to great! ( to rectify this i repositioned the sensor arm slightly)

the only other thing i could suggest could be wiring or water ingress , but in all fairness ive never had that sort of issue with a 307

seems odd its switched from left to right , did they unplug the right after they cleared the fault in the rear left??

Could do with the fault descriprion really

Good Luck

Crow

Posted: Thu 08 Oct, 2009 5:00 pm

Posted: Thu 08 Oct, 2009 5:01 pm

Canyondust

did you get my mail sent to your MSN?

Crow

Posted: Thu 08 Oct, 2009 5:18 pm

Coherence is when the sensor is working normally most of the time - then now and again fails to detect.
The cause is excess gap.

Posted: Thu 08 Oct, 2009 8:53 pm

Posted: Thu 08 Oct, 2009 8:57 pm

hi,,very doubtful.
as said air gap issues,get the garage to remove the sensors from there mounting point and clean the mounting point of its built up rust,clean up and refit.
all should then be well.

toddy

Posted: Sun 11 Oct, 2009 2:21 pm

Posted: Sun 11 Oct, 2009 2:47 pm

This is why live data or the scope method is good. So you can actually be certain of the fault.