mjc7600

My 2002 w210 wagon has had 2 brake light switches replaced in the last 14 months. Each time the esp & bas lights appear in the dash and the shift lever locks-out in park. Yesterday it happened again and was taken to a different mb dealer for dignostics. Today they inform me that the codes don't indicate that the problem is with the brake light switch, steering angle sensor, low battery voltage or corossion on the traction control unit. They are 90% sure it is the computer modual and the parts and labor with-out tax will be $1925.
Has anyone else had similar problems? The 320 4-matic has 56K miles on it.

mjc7600

Had the traction/eps/bas control modual replaced to the tune of $2042. The steering sensor which engages the power assist at low speeds is now getting signal from the computer modual but is not sending power back to the computer. The service mgr at the mb dealer doesn't know if the sensor took out the original modual or vice versa. He said to replace the sensor-which is attached to the steering rack, would involve spending $3000 to replace the steering unit. We ended up disconnecting the steering sensor to the computer . I will not have power assist at low speeds but at least the esp/bas lights don't come on, the brake pedal is sending signal to the stop light and the transmission lever isn't locked in park. Too bad the car is out of warrantee.

koskesh

Something smells funny here. Be careful buddy. It's a stealership. Get a second opinion before spending all this money there.
Did they try disconnecting the steering sensor before replacing the old computer unit? You should make sure that the computer unit was actually toast. I wouldn't believe them right off the bat like that.
You mentioned that the dealer didn't think it was the steering angle sensor. Unless you're absolutely sure that both the sensor and computer were bad, you should ask them for some reimbursement because they didn't diagnose it right in the first place.
How hard is it to get to the steering sensor?

mjc7600

The dealer check voltage coming out of the computer modual going to & coming from the brake switch,steering sensor,esp and stop lights. The old modual indicated problems with the brake switch and the steering sensor but when trouble shooting, they found current sent to the brake switch was returning and nothing was wrong with the switch. They checked that there wasn't any corrosion on the contact to the computer mod. After replacing the computer mod, the voltage to & from the brake switch was still ok, the bas/esp indicator lights did not reappear but the voltage going to the steering sensor did not come back out of the unit. Everthing interfaced with the computer mod was working except the steering sensor was not return signal back to the computer. They found the sensor switch to be not working which means it won't engage the power assist to the steering rack for low speed steering. You can not replace the sensor alone- the whole steering rack must be replaced which is why we just went under the car, opened the shroud covering the rack and disconnected the sensor connection which returns to the modual.

Ted Baldwin

............Ask them to first clean the module meticulously and reconnect it. This is an old trick for these things. If your tech knows what he is doing he'll know what I'm talking about. Also where do you live?

Ted

mjc7600

I had them check the connections for corrossion while it was being diagnosed.
I am in Elkins Park,PA and took the car to Keenan Mercedes in Doylestown, PA.

Ted Baldwin

............the reason I asked for your location was to see if you were anywhere near South Florida.

........There is supposed to be a special solvent used to clean the connections. The problem as I understand it is that there is fluid that is supposed to flow within the wires themselves down to the connectors. I know I sound like I'm out of my brain, but this is what I was told by a very experienced MB mechanic.

Ted

dsmith

This thread is a great reminder of why you MUST have an extended warranty on modern cars. Good luck.