[dcw]

All the functions you describe are certainly controlled by the CEM, so I think you are looking in the right direction.

I wonder if trying to charge it using an electric Mercedes has somehow fried parts of the CEM? I know nothing about electric cars and their systems, but a normal jump start such as you performed with your 940 certainly shouldn't have hurt the CEM at all.

I don't know any of the background to the problem he was having, and of course you might not either, but sometimes the connections into the CEM can be slightly dislodged by rummaging around in the glove-box/passenger-side footwell side area if by any chance that has happened.

I would be inclined to remove the plastic trim down there (pull the weather-strip clear, sharp tug to pull up the inner door-sill trim, sharp tug to pull off bonnet release knob, then one screw and pull the plastic panel away (it should be held on two clips if they are still present after all these years).

There are three multi-pin connections into a CEM3 to check are tightly home.

Otherwise, best bet is to try another CEM...

Hope that helps!

David