ABS light on

[Ed Kellock]

The Antilock Off light is constantly on in my '89 200q.

I found the information below at 20v.org and a new fuse lasted a couple of days until I
"tested" the ABS a few more times today.

If anyone had any additional information or other BTDT, please let me know.  My local
junkyard has a couple of possible ABS relay donors.  I'll see if I can obtain another
relay there on Monday for the sake of testing.  Couldn't find one online where I could
also find a price.

Thanks,
Ed



ABS Light ALWAYS ON
(J Tomislav)
Simple Check for it is the following
  1.. Remove footwell cover (driver's side ... this is actually the whole shelf).
  2.. Remove ABS relay (should be middle row all the way to left and it has a red fuse in
it which is 10 amp I believe).
  3.. Look at fuse ... is it blown? If so, then here is your problem. Don't bother
replacing fuse ... it will blow again. Replace the relay. If you still don't believe me,
go ahead and put in another fuse and I bet it too will blow. This will prove the relay is
toast.
The relay is found on all the 1990 - 1992 audi 90's and coupes ... regardless of
drivetrain. Best way to make sure is to look at the part number on relay.
What happens is that there is this mother-of-a-diode inside that I can only assume shorts
out over time. This diode is put there to 'absorb', if you will, any counter-EMF that
occurs from turning off the ABS pump, so that the rest of the car's electronics doesn't go
berserk.