ABS Warning Light

[deepblue]

I recently had the ABS warning light on my S4 come on - ABS had stopped working. I replaced the front nearside wheel sensor and the system is fine again, only I can't stop the ABS light from blinking. Any thoughts on how to stop this?

[cnh1990]

Did you disconnect the battery for a few mintues to reset the computer?

[deepblue]

Yeah, it stopped flashing after I reconnected the battery but started again a few miles into the journey.

[cnh1990]

I have heard there has been a lot of problems with the accumilator/pump with the ABS cars.
Calvin

[JK1]

Check your brake lights and see if they are working.

[superdave]

Question, how did you work out that it was the front sensor? Did you hook it up to a diagnostic equipment or something?

Cheers,


Dave Walters

[deepblue]

My mechanic ran a diagnostic and found the faulty sensor, he can't figure out why the warning light still comes on though. Brake lights still work fine.

[ErnestM]

While stationary cycle your emergency brake (to the limits on up), afterward, drift backward very slowly and then brake hard (regular brakes). Turn car off, turn car on - see if this makes it go away.

If that doesn't work, I would suggest having your tech check it out a little more closely...

ErnestM

[Deepblue]

Cheers Ernest, I'll give that a try.

[adrianmugridge]

You can get problems with the brake light switch on the pedal. It operates the brake lights when it should, but also when it should not, i.e. your brake lights can be on when your not touching the pedal. I'm pretty certain that this can cause the ABS computer to think that the brakes are on all the time and so it turns the ABS off.

Adrian

[johnwatkins]

Does the pump repressurise the system every time you press the pedal?

If so it's probably the pump & accumulator assembly.

Hope this helps,
Cheers,

John W
'95 S4s

[wcdeane]

You may want to check out this web site. It has some good trouble shooting info on the Delco-Moraine brake system that we have. It's not an exact match, but ours is very similar.

http://home.att.net/~aldridgec/TGP/brakes/powermaster.htm

Cheers...Walt '91 SE

[deepblue]

Thanks guys you're great help. I can't believe how useful this forum is and how widespread the Lotus 'brotherhood' extends! BTW Ernest's advice seems to have done the trick. Cheeeeeers!

[ErnestM]

Glad to help...

ErnestM

[Skerd]

ErnestM said:

While stationary cycle your emergency brake (to the limits on up), afterward, drift backward very slowly and then brake hard (regular brakes). Turn car off, turn car on - see if this makes it go away. If that doesn't work, I would suggest having your tech check it out a little more closely... ErnestM

Ernest:
I saw later on this fixed his problem. How??? What on earth would doing this accomplish? Just curious.

[ErnestM]

Just a theory - but I think that either the cycling of the emergency brake or the heavy braking sends a signal to the ABS that clears the condition. I have had the ABS light come on mine twice (both times when it has sat for more than a week) and this has worked both times. I subsequently had the system checked out during service (belt and suspenders=me) and no problems...

ErnestM

>> Edited by ErnestM on Thursday 26th February 13:46

[Skerd]

Thanks, I will remember that one.