Kobe209

Hi folks, just wanted to share my story.

Yesterday my drivers door window adjusters stopped working, the usual simptoms.
Rear view mirror adjustment not working, rear windows not working etc.
Upon searching I realised it's the damn DCM.

I began searching for the part, but as luck might have it my father-in-law is an avesome RTV tehnicial and I gave the board to him to look it over.

10 minutes later he discovered that one little black thingy is burned out, replaced it and HEY PRESTO everything works now!

Here is a pic, the part circled in red d'oh:




This may or may be not helpful to other people but if your DCM is already toast it's worth to take a look and try to scratch these little buggars with a screwdriver or something. If it's carbonated or falling apart you have a good shot at repairing it provided that you have someone who is experienced with electronics.

May also apply to other models.

megacrazy

Ah yeeesssss. I was going to do just this if any of the usual modules failed. It's usually a 10 cent component that needs replacing/soldering/fixing. I am glad somebody did the work and posted. Thanks!

Kobe209

Yes, it's just a matter of finding the part that's died.
Happy it's not one of the chips

Gadomaitis

Hallo, in my board, it was his neighbor transistor faulted. It left it in the place, because nothing burned out, just jumped two legs with small wire.

ryanrecce

Hi there, I am having the same issue as you with a Mercedes W209 Door Control Module. It seems that one of my transistors is burned in the same area that Gadomaitis has posted above.

Did you just bridge together the Collector and Emitter of the transistor and that worked? Is it still working?

I have uploaded some images online for reference here: https://imgur.com/a/g4kxq

Thanks!

ryanrecce

Also, I found an older article here where the author writes that there are (3) different DCM Part Numbers that should work. https://mbworld.org/articles/how-to-...s-replacement/

I currently have the 209 820 19 26 , but the only ones available are around $450-$500.

I did find a reasonable priced 209 820 21 26 and according to the article I posted above, this would be one version back.

ryanrecce

Update,

Update: I jumpers the emitter and collector on the transistor that was burnt out and everything now works properly. Saved myself $500! Hope someone else can benefit from this post. Cheers

zuzu_pali

do you mind doing a video tutorial ? also are other symptoms like the m not glowing up? or the seat wont move ? the buttons wont illuminate ?

Sándor Berczi

Hallo i need help please!
the component is burned.
what you see : 5C
transistor or zener diode?
Which one is good?
thank you!

C209 panel

Merc042

Hi I had the same problem my door control module would work intermittently so I took it to an independent Mercedes mechanic when he hooked it up to see what faults there are all he got was no communication with right hand door module he didn't know where to look so I found a canbus wiring specialist and he traced the wiring back from the control unit to 2 plugs that are located underneath the skirting board where the kick panel is he removed the kick panel and lifted up the skirting board and under that are 2 large plugs a blue one and a black one the black one wasn't making a good connection it was a bit loose and that was why it was working intermittently making a connection and then not so he just wrapped a cable tie around the plug to hold it firmly in place and all good now everything works perfectly so before going out to buy a replacement module check that plug make sure it has a good connection hope this helps someone