My 2004 E500 4Matic has an issue with the rear right door not opening from the inside. Opens just fine from the outside. A year or two ago I had the indy shop take a look at it to see what was needed. They said it was the lock actuator module, which I'm assuming is the door control unit. They didn't list a part number, I'm guessing it's part# 211 870 41 26 (https://www.pelicanparts.com/More_In...04126.htm?bc=c). I politely declined the $930 estimate for them to replace it. Not much on youtube for this module. If this is the problem, does this part need to be paired up with the computer or will it play nice with it out of the box?

Thanks in advance!

 

I replaced all four door control units with used units, with the same part numbers, no issues what so ever.
But, your problem is not the control unit. Like the name implies, it controls the door electrical functions.
Your issue is mechanical, between the handle and the door lock. Or the actual lock which indy already told you.

 

There are several p/n's for the left lock, A 211 730 05 35, -07 35, -09 35 and -11 35. First two locks are half the price of the later, so I assume they are manual locks, and the more expensive are power locks.
But you can check them from nemigaparts.com

 

This is my first post, so please bear with me. I have a 2009 E350 4matic wagon. The rear outside lights in the hatch don't work. I've checked every fuse in the entire car (that's not it). I'm close to pulling the trigger on the ECM (#211 870 26 85) but wanted to put this out there and see what the tide washes in . Thanks

 

I have found when the lights in the trunk lid or rear assemblies fail, it was a bad connection due to corrosion in the connector.