Abs

[citroenxm]

Hi all

OH NO not another ABS problem I hear you shout!!

Well kind of, I spoke a while ago about an ABS fault on my V6 SEi, were as the light is on, but the ABS still works! and I mean it..

Well, this DERV, has the opposite problem, the light is OFF, and the ABS still DOES NOT work!!

It does its useual light check, flickers with ignition on then goes out, but no ABS.. Now and again about ten mins into a journey it will decide to come on..

Anyway, I've tried another ABR unit, checked all Sensors, they are all ok, and today replaced the hydraulic block, and guess what, it still doesn't work..

So .......

Rgds
citroenxm

[onthecut]

Boring, but have you checked and re-made the first connection away from each wheel sensor ? Have also found on one or two of mine, much more inclined to play up in damp conditions, but never really got to the bottom of it.

Mike.

[Jan-hendrik]

Yeah, the ABS tantrums. If the sensors check out then it usually is the wiring. Cleaning the connectors near the wheels often solves the problem. But it could be a fault inside the ECU, a failing diode. Hope not

[citroenxm]

ECU is not a problem, I have 5 of the things! And they are in working order...

Cheers

Rgds
citroenxm

[xmexclusive]

Hi Citroen XM

I would agree with the suggestion that the connectors in the wheel arch and over the back axle are the most likely suspect. If this this does not solve things then the Bendix Hydraulic Unit has some electrical connections that are well exposed to the elements so it is worth checking/cleaning those as well. The ABS circuit has balancing coils which mirror the wheel sensors so a high resistance on any of the connectors throughout the ABS circuit can generate an ABS fault.

Regards

XMexc

[citroenxm]

Hi xmexec,

I fitted a known working ABS hydraulic block, and checked the connections, they were in good order, what do you reccomend as a good OHM reading for resistance across the sensor terminals??

I think I had about 2.6 ohms BUT DONT QUOTE ME I cannot remember exactly, I know it was low, and all four at the ECU connector were the same reading..

Rgds
citroenxm

[techmanagain]

There is/are connectors to relays above the Nearside headlamp and in front of the battery. The corrosion on these can easily show a fault on the ABS system. Pay partricular attention to the single one on the front of the battery box.