ABS and Speedometer

[razorho]

hi all,My W202 got an problem, when i am driving the ABS light come out and the speedometer stop work! after i stop the car and start the car again ,the ABS light turn off and the speedometer work again ,But the problem is the brake effect doesnot work good.....the ABS easy to take in the normal break action!

Anyone know the problem? I checked the car with the computer ,it shows ABS sensor fault (left front) ! So is it affect the funtion of the speedometer! thanks ALL

[c55m8o]

Welcome.

Did you recently change tires or rims+tires to something other then those having a 25" outer diameter?

Otherwise the search link is very useful and might return the exact results you need.

[razorho]

But the front left bearing broken ,and i just replaced it! is it the vibration of the broken bearing to make the sensor damage? I use the orginal rim set !!

[razorho]

today i fixed the front bearing ,front brake pad and the fuel pump and filter ,Due to the leakage from the fuel pump.....it really frustrated !!!! Money gone......but the problem of the ABS and speedometer still stick on the car!!!!! Thanks for the reply!:bored:

[c55m8o]

Interesting; could be. Perhaps you hit the wire and that affected the connection? I had a catastrophic failure of the front right bearing myself, and that destroyed my front right brakes & rotors too. I have to profess ignorance however about whether I had the sensor replaced @ the same time, as an MB stealership did the work. I'm sorry I don't know how to diagnose that. There are a few mechanics on this site. Hopefully they may check in.

[jnenad16]

what is the year and model?
sounds like a bad diff speed sensor.

nenad

[razorho]

My model is C200 1996

[stox]

Looks like I am joining the club on this problem. This evening, I pulled out of my driveway, and halfway down the street the ABS, ASR, Brake Pad worn, and Brake lights come on and the speedometer dropped to zero. I think my car is trying to tell me something. :(

First thing, tomorrow, I'll be checking fuses. Any suggestions on checking the sensors?

[razorho]

yes,i think you better to check with the computer ! For my case, the Left front ABS sensor Fault ,So make the light come out and speedometer fault ! For my knowledge ,the ABS sensor also have funtion to supply info to the speedometet! As a result,the fault of the sensor will cause the speedometer mulfunction! pls let me know how your story develop! Cheers and GLuck! ;)

[stox]

FYI: the solution to my problem was replacement of the dreaded OVP module.

[Denlasoul]

Originally posted by stox
FYI: the solution to my problem was replacement of the dreaded OVP module.
How was that diagnosed?

[stox]

Originally posted by Denlasoul
How was that diagnosed?

Two hours of my mechanic pounding his head against the wall. I think he has a concussion now. It does seem, with many Benz's, that otherwise unexplainable failures end up being the OVP. It was the original, so 10 years and +100Kmiles ain't a bad lifespan.

[livin503]

where did you get the OVP, how much did it run you, and is it easy to install yourself?

pardon my ignorance...

[stox]

In this case, my mechanic picked it up. If memory serves correct, it was somewhere around $70. If I had diagnosed it myself, replacing would have been easy, unplug the old relay, plug in the new one. Repair jobs don't get easier than that. Diagnosis can be another thing, though.

[livin503]

Originally posted by stox
In this case, my mechanic picked it up. If memory serves correct, it was somewhere around $70. If I had diagnosed it myself, replacing would have been easy, unplug the old relay, plug in the new one. Repair jobs don't get easier than that. Diagnosis can be another thing, though.

do you have a picture of where to install the OVP sensor?

[stox]

If memory serves correct, it is in the back right hand corner under the hood, next to the diagnostic connector. It is a relay, with a fuse on top of it, it should be easy to find.