Rear door ecu change

[bunnyrabbit]

Hello again. I have a 98 c250 TD Ssport diesel and am working my way through electrical probs with CAN B. (Im told that these probs begin with over-sensitive Merc software and will probaby last the life of the car) I have a dodgy rear window operation to the off-side door (again a common source of probs) and intend to switch ecu with the nearside door to prove that the ecu is at fault. Does the ecu have a unique address to the circuit of the offside door? Or, are the ecus on the same part number? Many thanks.

 

[bigasotonuk]

Hi,
I don,t think they can be swapped over as the Door Control Modules (DCM) incorporates the window motor as well and I believe they are handed Left and Right, though someone maybe able to confirm this.
I have never ever heard of them failling because of over sensitive software, they normally fail due to water ingress into the door and becoming damp. There is no coding on these, sourcing a second hand will be reasonably easy as any 202 and possibly 210 of similar age should fit.
If the fault is intermittent, you could try removing it and drying it out, then wrap it in polythene and refit it, worth a try.

 

[bunnyrabbit]

Hello. I'm sorry but I didnt explain the problem properly. Every few days something corrupts Can b and I lose everything served by it, indicators, washers, interior lights, central locking, windows, etc.. I reset it by disconecting the battery strap for 30 secs and things come to life again. It is a pain when the boot is full of golf gear. It seems that this is common with the C Class, I have spoken to a few people who have similar problems and the sensitivity of the software seems to be an issue. It seems to be easily corrupted making the vehicle unuseable. What a drag. I am looking for a fault that would cause the problem and have sorted some dodgy work by a previous owner on the stop and reversing lights. The boot light does not work despite a new bulb nor does the rear interior courtest light. The roof and the front courtesy lights have a mind of their own. They work one day and fail the next.
The rear off side window doesnt work and I have read in a lot of places that a fault in this can cause problems with Can b and this is my next plan of action.
I mistakenly believed that the ecu and motor were separate components and it looks like a breakers offering may be the way forward. Wish me luck. Many thanks.

 

[television]

Do take a look in the front fuse box with 2 lids, these can let water in and there are modified lids and seals now,,you do need to lift the SAM to check for any water under it

 

[bunnyrabbit]

Many thanks for the quick response. Will have a go at it tomorrow, after the golf. At 71 I have to get as many games in as I can, while I can. Regards A.