W220 S500 1999MY left door power not working at all

[FranksMerc]

Hi, everyone..I parked the S500 up for 3 weeks recently. When I went back to it, I found the battery was completely flat. Having jump-started the car, and since charged the battery, I was dismayed to find that the electric folding mirror on the passenger side would neither fold back out, nor adjust..the driver's one does...also, the passenger electric window no longer works, both from the passenger switch and the driver's switch..in addition, the electric seat adjustment on the door no longer works..
Is there a "common" problem here, perhaps, dare I ask, an "easy" fix, or am I in for a real headache?
Any help would be soooo appreciated...
Thanks very much.

 

[allenhouse]

with a jump start it's possible that the pasenger Door Control Module has been damaged, but you should check the fuse for this first...I think it's a 40 amp fuse, number 13 in the left side fuse box in the engine compartment. Check the fuse chart if you have it, to be sure where it is.

 

[FranksMerc]

Hi, thanks for that..I actually already checked the fuses, all seem ok..:-(

 

[allenhouse]

can you tell if the internal passenger door pull handle light is "on", and if the indicator bulb in the left exterior mirror flashes? If not, and you have verified that the fuse is OK, then it's likely a blown DCM.

 

[FranksMerc]

am not able to verify at the moment..will check the indicator tomorrow..where might the DCM be and is it an easy fix?

 

[allenhouse]

the DCM is inside the passenger door, a small control unit box which on the early W200s can be easily removed and swapped (plug and play) once you remove the door panel. I replaced mine a while back with a second hand one from Ebay. If it comes to that for you, then do a search on how to remove and reinstall the door card...a bit of work, but nothing too difficult for a competent DIYer.

I'd check the fuse again, and pull it/replace it just in case it's a simple supply jitter. The DCM controls the functions you mention you have lost, and a few others (handle light, indicator on the mirror etc) so it's looking like a DCM issue.

 

[FranksMerc]

I had a look on Youtube....would the faulty module be my passenger one, then, or the driver's one? The right driver's mirror functions, as does the window and seat adjustment..it is the passenger side one that is not working..wondering whether the driver's one regulates the passenger one, too, or whether they are independent of each other?
Thanks for your advice.

 

[allenhouse]

the passenger door DCM controls the passenger side functions, the one in the driver's side door handles the same functions for that side of the car.

You likely have a malfuctioning passenger door DCM. But, if I were you, I'd disconnect the battery once more, leave it five mins, and then reconnect - just in case this resets the DCM or any other electrical glitch. It's worth doing, even if it means you need to synchronise the windows and turn the steering wheel to get the ESP message to disappear.
Do you have a code reader? Or know someone who does?

 

[FranksMerc]

thanks for that..wil try that first and see what happens.....

 

[FranksMerc]

I am currently in the UK, my RHD car is in Germany....so am thinking I will try and get a repacement DCM, after all..I tried the disconnecting-the-battery-for-a-while option, with no luck. Is it correct, then, that the passenger DCM is at fault, when the driver's side controls do not operate (passenger mirror not folding out, window not working, electric seat adjustment not working)..just want to make sure, in case I may need both modules...
Thanks again for any help.
Frank

 

[allenhouse]

if the driver side DCM switches illuminate when you turn on the main lights, it is fine. If the lights are not on the passenger DCM switches...it has failed. Or the fuse has blown, but you say it is fine.
The driver side DCM can tell the passenger side to open the passenger window - but if the passenger side DCM is faulty, it won't obey that command - that's why you are thinking the driver side DCM is faulty, but it shouldn't be IF it actually opens the driver window etc.