Sunroof Closes But Then Tilts Open
 

2012 ML 350 (W166). *Sunroof (or sliding roof) will open smoothly and then close smoothly using the selector switch, but as soon as it fully closes, the rear edge opens to the tilt position. *Does this every time. *You can coax it down a tiny bit at a time, but it is very difficult to get it perfectly closed (no wind noise or water entry). *If you go too far, it tilts fully open again.

I have looked at reset procedures in other threads and in Youtubes, but the only ones I can find are for other models that have a 4 function switch (push up to tilt up / pull down to lower from tilt /push rearward to open fully towards rear / push forward to close). *This model has only a 3 position switch (push up to tilt up / pull down to lower from tilt -- also pull down to close from rear open position / push rearward to open fully). *The owners manual is no help.

​​​​​​​Anyone have the same problem and know how to fix it?

Mine does this too on my w201. Not sure what happened, but it's been like this for a while now. Only happens when when I am pushing it forward to close it. If I keep my hand on the switch, the rear will tilt up, it never use to do this before. So when I close it now I just push the switch forward until it shuts, then I give the switch a few smaller taps forward to get the rear to lift up and level out with the rear of the top.

A shop needs to relearn sunroof position of sunroof motor, ocp uses motor turns to learn open close , lift

If attempts to synchronize have failed your only option is to have someone with an SDS tester normalize the system. It could possibly be a faulty overhead control panel, aka dome lamp assembly.

Thanks everyone.

RPM55 -- do you know what the synchronize process is for my model with the 3 position switch? The vids I watch for 4 position switch tell you to push (up hold 5 seconds) / pull down (hold 5 seconds) / push rearward (hold 5 seconds) / pull forward (hold 5 seconds).

I can do the push up (hold 5 seconds). When I pull down, the roof tilts closed then immediately tilts back open, effectively screwing the synchronization process.

I would love to find an exploded diagram of the sliding roof with part numbers. If I had the diagram, I might be able to find the switch, remove it and test it.

Did you try the sync procedure found on page 98 and 99 of the owners manual? If you did and the sync did not work it is off to the dealer. The reset is different for sunroofs and panorama roofs with rollerblinds.

I did try the procedure with no apparent result. The procedure is very rudimentary:

"Reset the sliding sunroof if it does not move
smoothly.
- Turn the SmartKey to position 1 or 2 in the
ignition lock.
- Raise the sliding sunroof fully at the rear
(Y page 89).
- Keep switch pressed for another
second.
- Make sure that the sliding sunroof can be
fully opened and closed again (Y page 89).
- If this is not the case, repeat the steps
above again.
- If the sliding sunroof still cannot be
opened or closed fully after resetting,
contact a qualified specialist workshop"

From your above post about how the roof is acting it sounds like there may be an issue with the switch. What I would suggest would be to have it tested with an SDS tester to see if there are any relevant fault codes present and go from there. Sometimes just the presence of codes can have an effect on how some systems function. Also it is possible to normalize the sunroof with the SDS as well.

The dealer can do all this as well as some independent shops.

Best of luck, Robert

To close the loop on this, I had the vehicle in to the dealer for another issue and asked them to look at the sunroof. $150 for the first hour of diagnosis and they advised there was a stick/twig caught somewhere in the mechanism. For another $150 in labor, they would drop the headliner and remove it. I told them to go for it and they fixed it.