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Discussion Starter · #1 ·
Need help! My 99 W210 first lost front passenger seat/window/mirror adjustment. I used the battery disconnect reset, which fixed the problem, but it returned 4 days later. 3 weeks later, I have lost driver window/seat/mirror/wheel adjustmment. Both front sides are now out.

can i get solution ?!

thanks all

· Registered
1999 MB E320 - Brilliant Silver/Ash 155K
292 Posts
I dealt with the same issue for about 2 yrs. Didn't take it in b/c I'm the only one that rides in my car so the seats never move. Only problem was occasional drive through window difficulty.

Without boring you with the whole story, it seems that the rear (yes, rear) power window motors have what is called a power window control module as part of the motor. It communicates across the CAN BUS network. This can malfunction and not affect the operation of the rear window but throws an error into the CAN BUS that takes out the front seats, windows, and side view mirrors. This happened intermittently just as you describe. Reset with battery and all is fine until the gremlin is released again.

The problem is most likely the control module in the right rear window motor.
1) Disconnect the battery and remove the door panel
2) Disconnect the wire harness from the window motor, secure each connection with tape to protect from moisture and rattles
3) Reconnect the battery.
4) Now you won't know if this is the fix until you ride around a few days and see if the power gremlin comes out again so I reattached the door panel at this point since I don't have another car.

If the problem doesn't come back the PCM is your culprit. You can do one of two things:
1) Leave as is since no one uses my rear seat and window and you'll also avoid having to replace a window regulator on that side.
2) The PCM is available as a separate part on the web I believe I found at Autohausz(?I can't remember b/c it was 1.5 yrs ago when I did this.) for about $187 US. It is attached to the motor with 2 or 3 torx screws and looks like you can replace it without removing the motor.

The other 2 or 3 people that had this problem had accessed the CAN BUS connection in the front passenger footwell and disconnected sequential wires then reset battery until they found the one that caused the problem. In each case they found the RR PCM as the problem so I went straight to that. If the RR is not the problem I would try the LR and if that isn't it then you might need to try the CAN BUS network procedure. It requires numerous removals of the kick plate and with that held by 16 year old plastic tabs is another reason I didn't want to do it.

Sorry for the lengthy description and good luck.
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