ABS kicks in easily, while standing still, and even with handbrake..?

[RedBar89Cab]

Hi guy's,

I'm having an odd problem with my 1989 325i convertible, manual transmission.

The ABS is kicking in super easy. Just under normal driving conditions. It usually kicks in right before the car comes to a complete stop (even at very slow speeds), but sometimes it kicks in even earlier. And, no kidding, sometimes it starts engaging even when the car is standing still and I have my foot on the brake pedal. Also, it kicks on when pulling up or lowering the handbrake! This happens at the midway point of the handbrake handles travel. Weird...

I recently had some work done to the car. I had new rear shocks put on, a new drivers side rear wheel bearing, and the car was missing the brake pad wear sensor on the front left brake, so I put a new one on there thinking it would remove the typical E30 "Brake Lining" light that is illuminated (it didn't).

Also, out of nowhere, the trunk lid brake light has gone out. Now, I doubt that is related to this ABS issue, but I figured I would mention it anyway.


Any ideas as to what's going on??


Thanks!

[AndrewBird]

I'd check all the ABS sensors. They are magnetic and will pick up bits of debris and can cause them to read incorrectly.

Does the ABS light come on with the key turned to the run position (engine not running)? What about while driving?

[RedBar89Cab]

The ABS light JUST came on now, and the ABS early kick-in problem is now gone. I'm assuming because now the ABS is no longer functioning at all, hence the ABS light.

Any ideas?

[BMWManiac]

bump, did you ever figure this out? I have the same symptoms and problem....ABS started to kick in easy (coming to a stop in reverse, coming to a stop over train tracks) and then it finally quit working and my ABS light stays on at startup.

I've replaced:
computer
both relays on ABS pump

I have a replacement pump. I should mention that I don't know if the computer or either relays were good since I bought used.

[kaygeee]

bump, my ABS engages when coming to a stop in reverse and frequently engages when coming to a slow stop at a traffic light or slowing down at an apron. The ABS light does not turn on when the ABS is active but the other night I hit a bump and the ABS light turned on and stayed on for the rest of the drive.

I've cleaned the rear hub sensors but I was unable to remove the front sensors. The rears had a convenient flange/bracket to pry on to remove but the fronts do not.

I am looking for any advice that would assist me in the removal of the front sensors but also as to why the light turns on when not under lock up conditions but does not turn on in lock up situations.

Thanks!

[deeclue]

bump - having a very similar issue. Already cleaned all four sensors. Its really annoying!!

[Das Delfin]

if your abs light goes out after the car starts, but comes back on after going faster than 5mph, one of your sensors is bad. To find out which one, unplug all but one sensor and drive the car. The sensor that is bad will NOT trip the ABS light

If your ABS light stays on after startup and never goes out as described above, your ABS relay etc may be bad. Search the forum for more on that. Jlevie has a descriptive troubleshooting guide