Originally Posted by
CyberCG
I will definitely keep you updated.
I spent a little time in the electrical diagrams this morning to determine if the BCM cared in any way whether the transmission is a MT or an AT.
Apparently, the BCM is not involved or cares which transmission the car has.
So, if the above is true, you can use a BCM from an AT car in a MT car.
I'm going to buy another used BCM having the same Software level of 44/03 (44th week of 2003). The hardware build week is different from my original, but that really shouldn't matter. I think it's the Software level that is the most important.
The used BCM I am using now, matched all the build and level numbers, but still does not allow manual control of the rear wing, traction control or tow alarm disable. It does pop up the rear wing at speed as it should and then drop it down when it's time to.. Those missing functions could just be a result of the used BCM's age and gradually losing function.
I'll post an update after I receive and install the next used BCM.
I thought originally the replacement BCM solved your problems? Did the manual control of spoiler, traction control or tow alarm work with the original BCM?
It should be possible to find a replacement BCM that matches your original one either on eBay or at car-part.com Luckily used ones are not that expensive.
There must be other companies that can repair the BCM if you want to go that route. I am sure on the Mercedes forum there are more posts than on here.
You can try disconnecting the battery for 30 minutes. Then reconnect it and put the key in accessory mode right before it turns on and leave it like that for a minute or two to see if the replacement used BCM will sync with the car like I've seen in a previous post.