Intermittent ABS Light problem

[Thom 1]

Hi all, I have a small problem with my ABSwarning light, in that, having replaced 1 dead pump and 2 speed sensors and the brake pedal switch to cure a permanently ON light. It now comes on randomly during a journey. Switching off the ignition and then on again clears it but it soon reappears, usually 10-15 mins into a drive (regardless of how heavy I am on the brake). Have hooked up a fault reader, but it doesn't seem to be able to connect to the ABS ECU, works fine with the engine ECU though. I'm thinking the next step is either the ABS relay or brake sensor on the servo....any other ideas?

Cheers, 8)

[NottsCounty 0]

Usually an ABS sensor.....but if it won't interface with VAGcom then replacing all 4 could be expensive and pointless.

[delfinis38 1]

easy way to check a abs sensor is to put a volt metre across it and check the resistance of all four sensors. can't remember off hand what the reading should be but it will be obvious which one it is.

[joebloggsVR69 0]

You need to get hold of a decent fault code reader, I have a similar problem - bought a code reader from egay which doesnt work properly

 

I think you need to use the older VAG-COM too, v3.1 and an opto isolated lead

[pete_griff 0]

another thing - when you brake really hard, does one of the wheels lock up and not the rest - when one of my sensors failed, my rear left would always lock up first causing the car to skid rather nicely to one side every time under very heavy braking

 

admittedly not a particularly sensible/definitive/safe way to find out - but it may give you some indication...

[Thom 1]

Cheers for replies, sorted now though, was the loom connecting the brake position sensor, damaged where it is cable tied to another loom unneccersarily securely!