w210 electrical problem help!!!

[Torben Frydkjar]

Hi

i have a problem with cabin electric. i will try to describe.
often the front windows and mirrors dont work, then sometimes its the same with back doors, cabin light, trunkopener (mostly from outside) at the same time the whole central locking system dont work, and when it is badest the wiper, horn and blinkers do not work(hazard still work).
i have tried the mecanic, the first time they said low power on battery, ist fixed. That is not true, it always starts even in the cold conditions where i live.
two days later driving in the rain suddently the wiper began to run wery slow, and after that nothing worked. then i measured battery and it was fine, i checked all batt connections, disconnected the batt for the night, but that didnt help.
then i tried the mecanic again, he said that the pump under seat had run warm and print/component was no good, he also said that the car was working and that i could try to drive it for some time, but that i had to have a new pump. He tested generator batt etc. and found everything ok. i think that it was my luck he didnt have a new pump(1000$).
got home, drove for 5 or 6 days, then it was the same again.
then i took the pump out to see if that would clear the problem, but it didnt,( there is no moisture or oxidation near the pump) i took it apart to to see if it had any sign of being warm, it didnt.
i have checked all + and - wires for oxidation.
then i tried the mecanic again. this time he said that it was the roof unit that was short to ground in can system, he changed it with a used one and was happy to have found the problem.
after 4 days it was the same again, and after having used 1800$ and the car isent fixed at all i dont know what to do.
i have asked the mecanic how he determined which unit was bad, and he said that he pulled out the units one by one until the rest would work.
i am going to try the same, but can anyone help with info on where the units are placed and what they do, or help with any surgestions on what to do.
maybe i can get a carsoft/interface for the kodes.

regards Torben

[redwood]

you simply need to have your car connected to a Mercedes SDS multiplexer diagnostic computer. This is the only way to find hidden faults in all of your onboard computers. If you are not using this method of diagnostics you are simply wasting your time. We have tried the other aftermarket scan tools which could never quite achieve the detail of the Mercedes tool.

Regards

[Torben Frydkjar]

Hi
Thanks for your reply Redwood.
The mecanic i am referring to is an authorised mercedes dealer and they have it all. I dont know why they cant find the problem. I think that they might have 30 carlifts in the shop and that is only mecanic toolshop. They do karrosserie at another department. I have no other place to turn, other to travel to the other end of denmark to try another shop.



Regards Torben

[philstot]

Hi Torben,
I have exacly the same problem here in Melbourne, Australia, where it is a lot warmer than Denmark right now. I got my electrics tested by an auto electrician who is mercedes benz trained and he could not find anything wrong with his tester. It came up with two fault codes, 135 and 136 which appear to be O2 Sensor errors but he said that he thought it was a faulty relay somewhere. I will have a look at every relay and see if I can find the fault and if I do, I'll tell you. If you work out the problem before I do, please tell me too. thanks,
phillip

[Kajtek1]

Tracing bad electrical connectors on a vehicle can be a nightmare so brace yourself.
I have hard time to believe the mentioned items are controlled by car computer so I would check all power AND ground connections with high quality meter. It should be easy when the problem exist, much harder when it is intermediate. It happened to me that perfectly clean electrical connectors under big bolt would let the ghost voltage to go through, but would fail under the load.

[Patch's]

Torben what year and model?

[Hirnbeiss]

To troubleshoot your CAN bus, find the connector under the A-Pillar, at the bottom of the cable spaghetti. There, all 9 or 10 modules are connected, and you can pull them one at a time, reset the battery, and drive around for a few days to see if the problem stays away.
See p. 47 here:
http://www.mercedestechstore.com/pdf...2010-28-02.pdf

Mine turned out to be the right rear window module, which seems to be a fairly common culprit.

[Torben Frydkjar]

Originally Posted by Patch's

Torben what year and model?

mb e 300 td avantgarde 1999

[philstot]

Originally Posted by Hirnbeiss

To troubleshoot your CAN bus, find the connector under the A-Pillar, at the bottom of the cable spaghetti. There, all 9 or 10 modules are connected, and you can pull them one at a time, reset the battery, and drive around for a few days to see if the problem stays away.
See p. 47 here:
http://www.mercedestechstore.com/pdf...2010-28-02.pdf

Mine turned out to be the right rear window module, which seems to be a fairly common culprit.

Hi Hirnbeiss,
thanks for the advice. I found the connector under the A pillar and did as you advised. The last connector I got to, when I pulled it out, fixed everything except the right rear window. So, it must be the right rear window module, like it was with your fault. Where do I find that module? Thanks heaps for the great advice

[philstot]

Originally Posted by Torben Frydkjar

Hi
Thanks for your reply Redwood.
The mecanic i am referring to is an authorised mercedes dealer and they have it all. I dont know why they cant find the problem. I think that they might have 30 carlifts in the shop and that is only mecanic toolshop. They do karrosserie at another department. I have no other place to turn, other to travel to the other end of denmark to try another shop.



Regards Torben

torben,
have you found the fault with your electrical problem? My is the right rear window module, like Hirnbeiss said it was with his car