2008 MCS:

So, I bought a mirror off ebay that has homelink and auto-dimming. My mirror has nothing. I quickly figured out I need to add power for homelink, so I ordered the kit from ecstuning that adds two wires missing in my harness. Not a bad job to run the wires from the mirror base into the fuse panel and then add the two wires into the two harnesses.

Partial success: I have Homelink now working and it isn't active with the car off. Hurray!

Fail: can't unlock/lock the car. I know the receiver for the remotes is built into the mirror.

The German instructions indicate I need to do some sort of programming in order to integrate it to the car.

1) Is is a dealer-only thing? If so, what do I tell them so not to confuse them?

2) Is there software available (with cable) that allows me to do it myself?

Thanks!

 

Did you move the receiver from your old mirror to your new mirror? There's a walkthrough on how to disassemble the mirror to do it. That should solve your problem.

EDIT: Here's the link for walk-through with pictures. You don't have to put the receiver in the new mirror, it just needs to be hooked up and in the car.
https://plus.google.com/photos/11444..._ahqfLkrXmjQE1

 

(No permission to view Google album)

Upon further inspection, the mirror I bought off ebay is an R52 mirror and I have a R56. There are a lot of problems doing this upgrade if you take it on, so here's the 10K foot overview of what to do.

I started with a manual mirror: power nothing and had the manual dip dial on the bottom of the mirror. I wanted Homelink and thought "how hard can it be"?

I find the R52 uses a different frequency than the R56, so I went about trying to move the circuit board containing the reciever from my old mirror to the new one.

First problem: the stock cheapie mirror is actually glued together. You will likely destroy the mirror (I did) taking it apart. The R52 mirror comes apart easily.

Second problem: there is a little plastic ramp in the R52 that prevents the R56 receiver from fitting. Just trim that away with some wire cutters and it'll fit properly.

Third problem: The R52 mirror only has three wires going to the receiver board, you need four. Pull one wire from your old mirror connector and insert it into pin 1 and splice that wire inside the mirror to the brown wire going to the auto-dimming circuit board.

Re-assemble mirror and you're set. Took me a few hours to figure out what was missing and determine which wires will be fully powered.

I haven't tested the auto-dimming feature, but I can now lock/un-lock the car and the Homelink buttons are lighting up only with the key "in".