[noShame]

C200 -98 classic AUT 280000km

I have a problem with my abs/asr lights being constantly on and the systems not working. Both lights are on immediate after start and always stay on. The lights used to go out before, randomly, but now they are always on.

I have checked fuses, changed the break pedal switch and cleaned both front sensors. Did not find any sensors at the rear wheels so I suppose there is one sensor on the axle for both.

the rpm and km/h meters work fine = the sensor on the rear wheels is ok?

1. the cruize control does not work
2. the kickdown does not work (yes im sure this is the reason, it worked fine whenever the lights would go off.. it shifts down when i press the pedal, but when it reaches high rpm it doesn't shift up)
3. and now after me "cleaning" the sensors (using wd-40 electric cleaning compound) the doors don't automatically lock above 10km/h (they did prior cleaning, even though the cruize, kickdown didn't)

does these symptoms point to a abs sensor? do they point to a specifik, ie the front left?

also read that you can check with a multimeter if the sensor is working correctly by reading the resistance. But where would you connect the multimeter since it is a enclosed system as far as I can see? Included two pictures.


http://public.openmindedprojects.com/ABSSensor_Givare.jpg
http://public.openmindedprojects.com/ABSSensor_Kontakt.jpg
CAUTION - THE PICTURES ARE BIG no modems

 

[noShame]

Thanks will check that out! Is there any way to test my relay if it is bad, ie by using a multimeter or such?

Did actually check my sensor with a ohm meter, and my front right and rear sensor both gave a reading of 1020 ohms, but my front left was dead, gave no reading at all. Will go and pickup an replacement today, holding my fingers crossed that this was the only problem. If not, will go with the multipurpose relay you talk about

 

[noShame]

Changed to a new front left sensor today, but no luck :\
The ABS/ASR lights are still on, do you need to reset it in some way (turning wheel left-right), disconnecting battery?

The thing is, now the doors lock automatically when >10km/h after the sensor change.. Where do I go from here?

 

[noShame]

Did check the rear sensor using a ohm meter, gave same output as the good front wheel sensor. Should maybe check using a voltmeter and spinning the wheel, alt taking it off and cleaning it.

But one question, could it even be dirt or such that causes this because the system does not engage until a certain speed. My lights come on directly after the car starts.

Also, when the problem is fixed, will the lights go off and ABS start working or do you need to do a reset somehow, or turn the lights/codes off at the shop?

 

[noShame]

Read that models prior -98 only have one sensor on the rear but that models onward have two sensors, one on each wheel. I jacked up the car and discovered that mine sure enough has two sensors, they were hiding behind the heat shield on the wheel so I didn't see them the first time around.

Did a ohm reading, the left gave a reading of 1050ohms which was close to the readings of the front wheels but the right one was dead giving no reading at all. Cut the cord and tested it, had contact.. so it wasn't the cord but the sensor body. Will buy a new sensor tomorrow and fit it holding my thumbs.. ill keep you posted on the progress!

Btw, looking at the homepage of a local dealer there are three different sensors based on chassis number, but all of them are "no ASR". Does this mean that ill have to buy it from expensive MB?

 

[noShame]

Thanks for the info, had a number on the cable was very easy to find this way!

 

[noShame]

Success! I changed the right rear sensor today and started the car, the lights were on. I drove 20~ meters, still on. I drove a couple of meters more and did a hard break to stress the system, the lights went out and I felt the pedal pumping! Now the cruise control is working, the kick down is working perfectly, antispinn is working, pressing the ASR off button turns it off. Everything is working great again!

I want to thank everybody for helping me solve this!

Info below is for future reference when people are searching_____
keywords: abs, asr, sensor, kickdown, cruise control, break pedal switch, w202, ate

w202 C200 -98 280000km

Measured resistance on front sensors: ~1100 ohms
Measured resistance on rear sensors: ~1060 ohms

Model year 98 onward, two rear sensors behind the heatshield,
models prior 98 one rear sensor on the rear axle.

part numbers for my sensors
front left: a 202 540 23 17 (ate)
rear right: a 202 540 28 17 (ate)

I came to the conclusion that the door locking function when speed >10km/h is controlled by the front left sensor. Also my kick down function and cruise control did not function correctly/at all while I had a problem with the ABS system/sensors. This could be of some help to someone having problems with kick down/cruise and dirty/faulty sensors.

Again, thanks for the help guys - anybody having problems/help ask and I will do my best to help you.