ABS warning light coming on.. then off... then on!!

[quattrokid]

on the 90 q since we had its its been doing this:

this yellow light has been on since we got the car!!

how do you find out which ABS sensor is culpable without having to strip down all hubs?
or jjust replace the sensors?
could it also be worn pads and discs?

cheers

[ian20v]

Its abs wheels matey worn,or broken tooth.I had it checked out by mechanic.

[msh]

First check all four with ohmmeter, resistance must be around 1-1,5kom. If all four has normal resistance, so all four is fine. If all four is fine, then there is two ways how to find the one [or two or whatever ] which gives too weak signal - first - poor man's way - by removing hubs and checking distance, second - lazy man's way - with oscilloscope.
My A90q had all four sensors in working condition, but only one provided correct signal and one weak signal, I don't know how it is possible because on early cars they are secured with bolts

[amanda]

Originally Posted by ian20v

Its abs wheels matey worn,or broken tooth.I had it checked out by mechanic.

Check the plastic spacers...only pennies 1st ..............maybe a sensor on the way out

[b2_sport]

Scan the car with a Vag-Com for a quick diagnostic scan. Where are you in the country I could do this for you if you around North East London

[jevrem]

I think that audi 90q does not have a diagnostic for abs.

[dandan]

i had this problem on my passat and it turned out to be a switch/senor behind the brake peddle

[msh]

Originally Posted by dandan

i had this problem on my passat and it turned out to be a switch/senor behind the brake peddle

Don't know about passat but B3 ABS shares that switch with brake lights - no switch, no brake lights and someone will smash into rear end of your car

[Audi Dec]

I have the same problem with my WR but the light only comes on when it is wet or even if the road is damp ! I have checked all the sensor cables for damage but they are perfect so all I do now is when the light comes on I push the ABS switch and that puts the light out for a while or sometimes for the day !! Does not resolve my problem but I might get it sorted now car is off the road for the winter.

[quattrokid]

got same problem with the WR as well... but the 90 quattro got drowned last night.... I was passing a truck when we both went into flood water.

Battery red light came on then later in the journey home the yellow battery light in the DIS
came on and by the time I got home ( just) all the dials and lights where just about extinguished!!

this morning managed to get it to dealer

gonna get a good service and check over ready for winter use now that I am using it as a winter chariot.