W203 C240 Door Electrics Fault

[skymastor]

Hi all,

My 6 yr old W203 C class is ill.

I have noticed for the past month an intermittent fault with the drivers door electrics. Everything electrical (inc central locking) stopped working for a short period of time. It then came back on without a problem.

However, over the past month, it gradually got worse and now nothing electrical on the door works at all. After driving it for a long period, everything comes back on. But in the morning its all dead again!

It has the symptoms of a loose wire or maybe because the weather over the past month has got more damp and cold, that could that have an effect on it?

Does anyone have an idea what the problem could be? Or does anyone have a clue where to start fault finding on the electrics or any website that would hold the information of wiring diagrams and the such?

Your help is very much appreciated.

Thanx.

Sky..

 

[perdikoyla888]

You say nothing electric in that door works? maybe a faulty door module or a loose/corroded connection. I think it worth checking it out. I hope this helps

 

[skymastor]

Thanx for this, your right, everything goes dead, even the central locking, electric mirrors and indicator on the wing mirror.

But before I start to rip things apart and in the absence of a Haynes Manual, where would I need to be looking for the door module?

 

[Goody (UK)]

Hi Skymaster,
i have just had the same problem on my 02 C270CDi AV Estate.
See thread for symptoms.MBClub Forums > Technical > Electronics C270CDI Electrical problem

Fixed it with a new door control module DIY fitted ( dead easy job )
But you may need to visit a dealer to have SRS warning light reset,
I believe there is a method to protect against it coming on when you unplug the drivers door airbags, but I do not know it.
Module cost me £111 Incl Vat from my local Merc dealer, He had one on the shelf & said it's a common C class fault.
Hope this helps.
Goody.

 

[Goody (UK)]

Sorry missed out the 'where is it' part.
This is what I found, whether a 2000 car is the same I do not know
On my 02 C270 the module is behind the door card,
Any way, here goes.
Remove trim from lower part of door pull/handle(clip on/off) this reveals
2 deep set Torx type screws
Unplug SRS plastic bung to rear of door card , remove 1 Torx screw(same size as others)
Start at the bottom of the door & pull/unclip panel (take it easy,as the plastic clips can pull out of the door card material )
Ease the door card up out of a tight seal running along the window seal.
this may be easier with the window down.
Now you will see the door module attached to the door itself. everything unplugs & the module itself should unclip.
Hope this helps.
Goody

 

[skymastor]

Hi Goody.

Thx for your advice. I read your thread and you have had the same problem as me! Apart from the drivers door going dead, all of these other weired electrical problems have just started to happen! It most definitely must be the door module then.

Well, before reading what you have put into this thread, I had tried to take the door panel apart earlier today and I gave it in as a bad job. I did not have a manual and I was fearful of damaging anything that was connected to the door panel!
I got as far as removing the screws from the door handle, removing a plastic cover around the lock mechanism and pulling all the clips on the door panel away from the door itself, leaving the panel hanging off from the bottom. I could not get the panel away from the door. The top part was still attached. I could look up inside the panel and see all the stuff that was connected to the panel (i.e the SRS thing & door lever mechanism!). I did not want to go any further because I believed that I would damage something. I have lots of questions below and thank everyone for their patients in advance.

When you say "door card" do you mean door panel? You say "Unplug SRS plastic bung to rear of door card , remove 1 Torx screw(same size as others" Do you mean take it away from the panel/card? Would this then leave the panel/card free to lift up wards and off the door? What about the door lever mechanism?

I will not be able to put the window down because the door is yet again totally dead. May all work again when I go for a long drive? Because of this, do you think this is why I could not get the panel/card to lift or could it have been that I did not take off the SRS thing and the door mechanism from the back of the panel/card?

One final bit, where exactly is the module? Is it inside the door behind the black foam seal or is it somewhere attached to the back of the panel/card?

Thanks very much for you help here. I will wait for a response to what I have put above and have another go soon. I have downloaded the Mercedes WIS document for taking out the Command unit. Does anyone know where one could be for the doors (or all other parts of the car) somewhere on the net?

Thanx very much for all your time.

Sky...;-)