1994 Xantia 1.9TD SX ABS nightmare !!!

warrym · Post by **warrym** » 28 Aug 2003, 02:34

Hi All,
I have a 1994 Xantia 1.9TD SX which has a really annoying ABS problem. Bascially it goes through ABS sensors every two months, I get the sensor replaced and all is well for a while then all of a sudden it happens again. When it fails the ABS light comes on and the pedal pulses slowly just as the car is about to stop (it has nearly caused me to crash twice!). However, if I then turn off the ignition and restart the car the ABS light will come on during its self test and then go out again, untill the next time it goes wrong etc. This gets worse and worse over a period of a few weeks untill I only feel safe driving the car when the ABS light has come on.
Each time I have taken the car to the dealership they put the ABS system on their diagnostic kit and say that its a faulty sensor each and every time. I have come to the point where I have given up replacing the sensors and only bother to replace them when an MOT is due. Any ideas?
Thanks
Martyn

blueboy2001 · Post by **blueboy2001** » 28 Aug 2003, 03:47

Pull the lead to the green abs relay, found under the cover just behind the battery. Apparently this turns the light and the ABS system off.
Mine doesn't work either, I've given up messing with it now.

Dave Burns · Post by **Dave Burns** » 28 Aug 2003, 03:49

This sounds a bit more sinister than a sensor fault to me, post this on the bba reman forum, if you can get an answer to this problem anywhere, thats were you'll get it.
http://www.bba-reman.com/abs.htm
Dave

AndersDK · Post by **AndersDK** » 28 Aug 2003, 06:14

Martyn -
Most definately this problem is related to common automobile electrics/elctronics problems.
These problems are bad/false chassis earth points, chafed cables, corroded cables/connectors, loose/broken spring contacts in connectors, broken cables under the insulation, water ingress in ECU's etc. etc. etc.
You may even have a mix of several of these problems.
Even for experienced specialists - such problems can be a nightmare.
There is one clue in your problem desciption however :
if it's a fact that the wheel sensors becomes defective over a short period - I can only see 2 major problems :
1) the sensor cabling is strained by vibration.
2) the cabling is fitted incorrectly w/ sharp bends.
These possibilities can easily be checked by measuring the ohmic resistance in the sensors - should be in the vicinity of 1K ohm.
Usually the cabling for these sensors are highly flexible silicone - but they can NOT withstand ANY strains by incorrect fitting/bends. The cabling simply breaks up under the insulation.
This is fairly unknown to most garages.

warrym · Post by **warrym** » 28 Aug 2003, 17:20

My local Citroen specialist has just discovered that the near side ABS wiring was routed incorrectly and was chaffed, which he has sorted out. The ABS is working perfectly again, with a bit of luck it will continue to do so. So Thanks for all your help.
Its interesting that in the last five years i have owned this car two Citroen dealerships were unable to work out what was going on. I think they just fitted a new sensor each time and fiddled with the wiring to get it to work!
Thanks