2006 ML 350, just back from the balance shaft repair and now I get a "Doors Open" warning every time I start moving. The doors are actually shut. The mechanic said the Star system shows both rear doors open when they are closed, and that the latches need replacing. I can (carefully) actuate the micro switches in both sides, and they "click." The problem appeared all at once, never having done this before the balance shaft repair. The battery was disconnected for a few days during this work. It makes no sense that both rear latches would fail at once. I don't even think the mechanics had the rear doors open for the job. Is there something they could have left disconnected under the hood? Any advice would be appreciated.

 

You have to clear the codes with a scanner.

 

So I tried the scanner; there were no codes stored. I performed a memory clear anyway, but it had no effect on the problem. Does anyone know where the rear doors send their "closed/open" signal? What are the wire color codes, where is a good place to disconnect so I can ring out the lines and prove whether the switches are working? Thanks!

 

If there were live messages in the Instrument Cluster then there has to be codes stored in the Instrument Cluster.

Is you scanner capable of scanning and reading codes in the Inst. Cluster?

 

I'm using the iCarsoft MBII. I cycled through all the parameters, read the codes (none,) and did the reset on each anyway. Am I missing something? There was nothing stored in the instrument cluster. I drove it, got the warning, checked again. Still no code stored.

 

What parameters? You are using the wrong terminology. Parameters come into play after you get the correct code. You have a door issue and just because the I.C. illuminates, it doesn't mean that the code/s will be stored there.

The code/s will be stored in the Door Control Module. If your code reader does not support those modules, your code reader is useless.

Here is a sample of some codes for the door control module.

 

Sorry if my terminology is off, I'm a newbie MB owner and a newbie to the forum. My scanner does read the door modules; it finds three. One is for the left, one for the right, and one for the tailgate. I don't see any codes anywhere in them. I'm puzzled that there appear to be no modules for the rear passenger doors. Do the two I see handle all four doors, or is there something hidden? I don't see reference to rear door modules in the WIS either. I'll admit that the WIS is a bit troublesome to navigate; I may be missing something there as well. Where, in the vehicle, would the door modules be located?

 

The front door modules control all four doors.

The problem here is that you do not know how the repair shop treated your car when they had it.

Don't believe anyone who tell you that both latches must be replaced.

Do you have your own scanner, not a cheap code reader?

 

I'm using the iCarsoft MBII. It is a scanner, and it will access all the modules in the car. It will read stored codes in any of them, reset the codes, and show live data. The rear doors show "open" when they are closed, and the state does not change when they are opened. I agree there's no telling how my Benz was treated while I wasn't looking, but I'm at a loss as to what they could have done to cause this problem. If I knew where the door modules were, I could do more troubleshooting.

 

The door control module is inside the door behind the liner.

 

The live data for the door latch micro switches is in the Central Locking submenu of the rear SAM in my scanner. So I spent some more time in the WIS, which is still difficult for me to navigate. I found the wiring diagram for the rear SAM, and it sheds some light. Looking at the diagram, it shows that the micro switches skip the door modules entirely and are wired directly to the rear SAM. The (poor) diagram in the WIS leads me to the right rear corner of the vehicle in search of the SAM- but all I find there is the rear fuse block. Does anyone know where the rear SAM is located?

 

Success! The SAM had been exposed to moisture. After locating the rear SAM I found the correct connector, removed it, and measured the outputs of pins 4 and 8 (left and right rear door micro switches.) I watched my multimeter while my wife opened and closed the rear doors, and it changed state each time, "grounded" for door open, "ungrounded" for door closed. This proved the switches and wiring were intact. I disconnected and removed the SAM, which was dry but had some light staining from water. Getting the board out of the case was tricky, but once inside I found areas on both sides of the board with residue consistent with water pooling then evaporating. I cleaned it using electronic cleaner aerosol with a toothbrush and some swabs. After drying I reassembled and tested. Voila! The doors show the proper state on the scanner, and the "door open" warning is gone. I also cleared the fault codes from the rear SAM, which had registered various open circuits as I unplugged it. Thanks for the help!