BAS/ASR Light & Cruise Control Help Needed
 

Very similar problem in my '99 C280, but all the previous posts seem to be for earlier model cars. The BAS/ASR light comes on at random occasions and when it does, the cruise control doesn't work either. Nor does the ASR defeat switch. In checking the brake switch, one of the contacts inside it looked like it had been arching so I sanded them both smooth and put electrical grease on them. The light went off for a day and now it's back on.

Another post suggested brake dust buildup around the wheel sensors might cause a problem (???). I checked all my 10 amp fuses (per the suggestion of another post) and found nothing unusual. There didn't seem to be any fuses labeled "ASR," "BAS," "Cruise" or anything like that under the hood or in the trunk. Any input is greatly appreciated!

You should scan the controller and see what it thinks is wrong. Proceed with testing from there.

I had the codes scanned and the only one that came up was for the O2 sensor, but that was because the car ran out of gas the other day and sent some water or something through the fuel system near the end.

When I start the car, the BAS/ASR light is off until the moment I press the brake pedal for the first time. Then it remains on until I shut off the car.

I also inspected and cleaned the magnetic rear-wheel rotation speed sensors. They were covered with metallic particles from who-knows-where. Unfortunately, the light is still on. I have a feeling it may still be the brake pedal switch. Anybody know how much one of those runs?

Any more ideas? Thanks, Dan

You are looking in the wrong controller if you got an O2 sensor code. You must look in the traction control. It could easily be a brake light switch problem.

Try replacing the brake lamp switch 001-545-01-09 for $15.50 OR spend the $$ & have codes read from TRACTION system.

Replaced the brake pedal switch. Problem solved.

I tested the old and new ones on my multi-meter but couldn't tell a difference. Oh well....

Steve and MB Doc: thanks for your input and expert advice!!!

Dan