andkud

Hello
Have a 1997 S420 have this problem just started,
ABS and ASR light come on as soon as the car is started and stay on,
when i push ASR off button nothing happens and cruise control does not operate, (when i start with brake pedal depressed light dont light up and asr off button work, but as soon as i release brake pedal ASR and ABS light come on.
Any body had this problem, may be found a fix,
I have cleaned all 4 abs sensors and tone wheels, checked all wires around wheels,
please reply if you know anything

THANK YOU

Gthrill86

I have a 93 300SE. I had the ABS light come on when the brake pedal was depress after starting it in the mornings and would stay on and the cruise control would not work. Check for a blown fuse or a bad stop switch. New switch fixed my problem.

syljua

The brake switch is a dual contact switch. One is on when you press
the pedal, the other is on when the pedal is released. This, so the
ASR know if you press the pedal or not. A fault is given if both
are on or both are off at the same time. Why two? This is to prevent
false assumption when a single contact is stuck closed or stuck open.

With your perfect description of whats happening with the pedal in,
I would say, your problem will be fixed by replacing the switch.
Not expensive, and buy the original part.

I have replaced it previously. I still get the lights up now and then,
in stop and go traffic, so I might buy an original part. Measure
the part that you get out, and you'll see that by wiggling the
prong, and load it sideways, the on/off circuit do not always give
correct reading.

BTW, heres an image of the part;
http://autoimport.dk/mercedes_webcat...em/0015450109/
and parts drawing;
http://www.detali.ru/cat/oem_mb2.asp...SGR=015&SGN=01

br,
syljua