2000 E320 windows, mirrors & trunk release quit

[ohbenz]

These all quit working at the same time.
I have checked all fuses, remove ther center console and checked the connections, unhooked the battery and reset. Still not working using the buttons on the console or the back door buttons.

Any ideas?

[Gilly]

I sure can't think of anything they have in common, not all three things, except the control panel (in the center console) which you've checked. I'm sure if you spilled anything on the console you would have mentioned it. How about the sunroof? Or anything else with a switch on the console? I'd lean towards a new center console switch assembly, may be worth having a diagnosis done at the dealer. If you want to avoid that (not advised) I'd try a new switch assembly, it's easy to replace. That's all 1 piece, as you may have noticed.

Gilly

[ohbenz]

The sunroof works, and I do have power going to the console switchs when testing with a test light. It doesnt make any sense, I was wondering if it has a control unit that operates the mirrors, windows, trunk release in one? Like I said I checked all of the fuses, I couldnt image all of teh switches going bad, including the rear passenger ones on the back doors.

[Gilly]

Ooo, sounds like you're not quite up to date on how this all works on this car. Yes, there are lots of control units on this car, there is a "door control module" (DCM) in each door, this controls mainly the window in each door, but also the mirrors, locks, etc. The switch panel you took out is technically referred to as the "Lower Control Panel" (LCP). The command for example to lower a window is sent over an information "bus", referred to as the "CAN" (Controller Area Network). So by pushing a window switch or the switch to pop the trunk, all you are doing is sending out a command to do it, you aren't really sending the power out from the switch to operate the window motor. Yes there is power going to the lower control panel to make it operate, but the power isn't distributed to the individual motors or relays. The power to operate the window may be supplied for example to the door control module for power up the window motor, but not to the console switch itself. There is also a module to operate the trunk, I think it's under the back seat (I wouldn't bother looking for it). In this case the use a special module called a SAM (System Activation Module) which is used for various tasks where a seperate module wouldn't make sense, in this case they refer to it as the Rear SAM, it would have several tasks besides popping the trunk. Hope this info is helpful. It explains how it works, but as you can imagine it would be hard for someone to fix this without the correct equipment (shop computer, etc). That lower control panel is rather sensitive to liquid contamination, so if you have the slightest thought that it may have gotten wet, I'd at least price out that lower control panel.
Gilly

[ohbenz]

If this switch did get liquid in it and shorted it out, wouldnt the rear door windows switches still operate the rear doors? Just wondering, the LCP is about $350 and I would hate to purchase one to find out that is not the problem.

[Gilly]

Not sure. Actually now that I think about it, isn't there that small switch on the console that keeps the rear windows from working? To keep the little scuffers from playing with the windows in the carwash or next to the biker at the traffic light? If so that may explain why the rear switches are also inop. Best expalination I can come up with. I thought the switch was alot less than $350. For that amount I'd pay to have a diagnosis done, but you can get it diagnosed and buy the part from Fastlane (better price and helps support this site) and install it yourself.

Gilly

[mbdoc]

On the 1998 & later cars with interior CAN network you must test (talk to w/scanner) all of the computers on the network. MANY times a computer that is still functioning can cause the rest of the network to crash. THE connection for the interior CAN is in the RF door sill plate area, voltage tests there will find the problem causing computer.

[mpolli]

Originally Posted by M.B.DOC

On the 1998 & later cars with interior CAN network you must test (talk to w/scanner) all of the computers on the network. MANY times a computer that is still functioning can cause the rest of the network to crash. THE connection for the interior CAN is in the RF door sill plate area, voltage tests there will find the problem causing computer.

Can a standard OBD II scanner talk to these computers? If not, where do I get such a scanner? And where is the connection point for the 1998 C series for the interior CAN bus?

Thanks,

Mike

[mpolli]

I believe I have the answer to my own question. I believe the scanner to use is a MT-2500 along with the appropriate cable and adapter.

Mike

[TimFreeh]

Originally Posted by mpolli

I believe I have the answer to my own question. I believe the scanner to use is a MT-2500 along with the appropriate cable and adapter.Mike

I have an MT-2500, it does not have this capability. AFAIK you need the dealer SDS to do this sort of communications.