bocalvin

I have a 2000 C230 Kompressor Sport with about 120K Miles. The ABS or Stability Control, I don't know which, intermittantly will grab one of the front wheels, just for a second, then let go. Everything goes back to smooth driving normal except the BAS warning light comes on when it happens and goes off only after I shut off the ignition and restart.
I replaced the left wheel ABS sensor because it was happening only on the left, but today, it happened again, on the right. Any suggestions on what is failing? Something as simple as a dirty sensor?

pcy

You can try to remove the sensor and clean the sensor as well as the wheel with teeth (behind the wheel hub). My guess is that sensor is at its end of life. While you go thru the hassle of removing the wheel and remove the sensor, you might as well just replace with a new one.

bocalvin

Thanks for the input. You are probably right but could it also be something upstream from the wheel sensors? Something common to the wheel sensors?

Glyn M Ruck

Sounds like sensor trouble but please make sure that you flush your brake fluid every 2 to 3 years. If the main ABS unit fails it is a fairly expensive fix. Dirty fluid with high water content kills ABS units.

bocalvin

Tell me more please, because we replaced the sensor on the left front, that was the only wheel that was grabbing. After the change, the left wheel continues to grab intermittantly. Any ideas on what else it could be?

pcy

If the left front caliper is grabbing even after changing the wheel speed sensor, then the corresponding valve in the ABS pump/control module may be the root cause. Either the valve is intermittently sticking -> causing the caliper grabbing OR the ABS control module is sending intermittent wrong signal to the valve -> causing the same.

Try this... remove the fuse for the ABS pump and drive for few days and see if this problem shows up. If the problem doesn't happen with the ABS fuse removed, then you know for sure the root cause is the ABS unit. PLEASE NOTE that when you remove the fuse for ABS, your ABS is disabled and your normal brakes should continue to function normal.


There are places that re-build ABS pumps and ABS control modules.

LILBENZ230

The BAS and ESP won't work when ABS doesn't. It has to be ABS related.

namierequina

this problem looks the same as mine but since this post was long time back, i would like to know if the problem has been sorted out or not. please let me know what is the rootcause and how it has been solved, as i am afraid if it will cause big accident to me later on.