I opened the sunroof on my 2005 ML350, drove a few miles, then found that it wouldn't close. It's stuck fully open, I've tried all the usual fixes (reset via pulling fuse 4, etc.). When I attempted to close it via the 4mm Allen wrench into the motor housing, it would not budge. Any good ideas?

 

Get on a high ladder and inspect all 4 sides and look for broken piece/s of plastic..

 

Thanks for the reply. I have tediously inspected the entire area and can find no debris. Two local indys have not been able to resolve the issue. i fear I'm looking at having to remove (or have removed) the headliner to get at the sunroof "cassette" to determine what's up. Perhaps a broken cable? Whatever it is, I suspect it's going to get expensive!

 

When you tried to attempt to close it via the 4mm Allen wrench and it did not close, it cannot be an electrical problem.

 

As it turned out, the sunroof module was not worth repairing. I had it removed and replaced with an scrapyard unit.

 

So replacing the module fixed the problem??
or did you replace the entire sunroof assembly?

 

I replaced the entire assembly with a used unit bought from a breaker yard. About $700 parts & labor.