W212 Command not working Seats not working???

[Denr]

I'm doing up a W212 E350 accident damaged on the front. My problem is that the Command is not working. Nothing. No power to screen or audio. Does not come on with the on/off button. Any ideas?
Also the power seat adjustments have no power/not working. Could these be related?

 

[zipdip]

Suggest it is fuses,all the fuse boxes are very like the w221 S320 on that car the fuse for the command is behind the rear centre armrest,on the W212 it is number 26,there are loads of fuses for the seat functions I think there is one for every thing a seat does,so the fact the seats do nothing would suggest not fuses because why would about 6 fuses go at once,as you have a car that has taken a hit,maybe it has shaken something loose,but I think you have two different problems as neither the seats or the command share any fuses

 

[richard]

There seem to be a rush of people fixing up crashed Mercedes and hoping that they may magically find the fault.

In order for the car to work properly, you need to get a Star Diagnosis / Xentry quick test done, and then fix all the faults, and you know they are fixed once you have done another quick-test and it is clear. Any aftermarket diagnosis is not good enough to really help you here.

Looking at the standard fusemap is not useful for many things, because it gives you all the fuse related to a function and it also doesn;t tell you about the fuses that users are not expected to touch.. So seats may include the main seat power, the power to the door controller that is used for the seat buttons, additional fuse for dynamic seat pump, heated seats, etc etc etc..

The big ones are the ones where you have to have some degree of clue before you go fiddling or bad things can happen. You don't want a user having to change a 160A fuse

The screen and the COMAND itself have different power feeds. So if by "no power to screen or audio" you mean that you've removed the COMAND and the screen and tested the power feed to see if there is no power, then it is not the individual fuses - *all* of which by now you should have tested in anycase with a test probe if you are working without or without the ability to use WIS (circuit diagrams).

I suspect that you have blown one or more of the main fuses that is between the battery and the other fuseboxes in the car. These are located in what is called the pre-fuse fuse box under the bonnet which is hard to get to.

This would tie with the seats not working, as from memory (i.e last time I looked, some time ago) each seat has a separate fuse to the main seat controller.

Before you go *anywhere* near the pre-fuse box you must disconnect the earth wires on any batteries in the car. There are probably 2 in your car (a big one and a little one) but I haven't ever checked. Earth is BROWN on Mercedes. Always disconnect before disconnecting the +12 !!! (I also suspect on a W212 you need to remove the main battery to get at the pre-fuse fusebox)

The pre-fuse fusebox is part of the jump start terminal, and has to be pulled out and opened up to see all the fuses. There are lots of big fat wires going into it and there are 80A up to 160A fuses in there (can cause you serious damage)

Please don't go cheapskate and buy cheap fuses, buy the correct ones from Mercedes Benz then they won't mysteriously blow whilst you are driving along and cause something major (like engine or power steering) to stop.

Cheers

Richard