W140 ASR/ABS Light On - PeachParts Mercedes-Benz Forum

doctorc · #1 11-29-2008, 12:19 AM

Recently my ASR/ABS light came on.

I have read the forums and have replaced the battery, the brake light switch twice, and cleaned the wheel sensors. I also replaced the high mounted brake light bulb.

The ASR/ABS light comes on primarily after cruise control has been angaged.

The ASR/ABS light also has begun coming on at speeds below 55 mph but does not come on at intersate speeds even when the cruise control is not on.

The ASR/ABD light goes out after the car is stopped and started.

The car does not go into limp home mode but runs fine. Also, the cruise and everything else works fine except for the steering becming very heavy when the ASR/ABS light comes on.

Both throttle actuators and the wiring harness was replaced about three years ago.

Any suggestions?

Arthur Dalton · #2 11-29-2008, 04:06 AM

Check for equal PSI and tire size..........

doctorc · #3 11-29-2008, 07:54 AM

Thanks for the reply Mr. Dalton:

I checked the tire pressure and all four have about 35 pounds of pressure. The tires are identical. The rear tires are newer but are worn much more than the front.

deanyel · #4 11-29-2008, 08:48 AM

What year and model? You've written this exactly as if you have a combined ASR/ABS light, which I don't think is true.

doctorc · #5 11-29-2008, 06:44 PM

Mine is a 1994 W140, S600.

I do have two lights, an ASR and an ABS light but they come on at the same time when the malfunction occurs and go off at the same time as well.

Thanks!

deanyel · #6 11-29-2008, 07:38 PM

Have you read the fault codes on the 38 pin connector - especially pin 7? That would be a good next step.

RT930turbo · #7 12-13-2008, 03:12 PM

Hello all, I'm a first time poster, but I've been a lurker here for years

Any word on the cause? My 94 S600 does exactly the same thing.

exkiwi · #8 01-26-2009, 03:42 PM

I have the same problem with my 1994 S500 W140. Both the ABS and ASR lights stay on and do not go out at anytime until the key is turned off. The problem appeared when I made a hard emergency stop. I have replaced the sensors and pads. Can the problem be fixed with a reset? How?

zcc · #9 01-27-2009, 03:45 AM

I'd recommend checking both brake switch and brake bulbs from the correct Watts.

Western140 · #10 01-29-2009, 01:33 AM

I'm having the same problem with my 1998 S420. I actually had both the ABS and ASR lights come on and stay on, even after engine restart, a few months ago. I had the brake light switch replaced, and that fixed it for a while, but recently the problem has returned.

Now, the ABS and ASR lights come on most often when I am just feathering the brake pedal, such as in stop and go traffic on the freeway, when I feather the brake and then let off. Or, also when I'm parking it happens a lot. Now, however, the lights are reset after engine restart.

Is it possible that I just need to get another brake light switch?

zcc · #11 01-29-2009, 05:11 PM

Quote:

Originally Posted by Western140

Is it possible that I just need to get another brake light switch?

I think you need first to pull the error codes and see what's going on.

Western140 · #12 02-03-2009, 02:11 PM

I took my car to my indy last week for the ASR and ABS warning light problem. He said there was an error code pointing to the brake light switch being faulty, so he replaced it again and just charged me $17 for the part, which was nice. I have the one he took out (which he had installed just six months ago) and it's already partially jammed in the closed position, and it doesn't move freely at all...very sticky jerky movement in the switch. I can't believe such a small simple part would ever fail, much less twice in six months. Anyway, hopefully the fix will last longer this time. The BAS/ASR and ABS lights haven't come on since the brake light switch was replaced, and it used to happen most days, so I think that was the problem.

Arthur Dalton · #13 02-03-2009, 02:21 PM

It is best to replace with a switch directly from Benz. All others have a high fail rate.