Mercedes Viano Sunroof Issue After Coding

That sounds frustrating. I had something similar happen on my Renault Megane after electrical work, and a sunroof reset was needed. Does the error message mention a reset? There might be a specific button sequence to reinitialize it. Is it possible the coding messed with the sunroof's settings?

A reset makes sense. When you say 'specific sequence of button presses,' what do you mean? I checked the owner's manual, but I can't find anything about a sunroof reset procedure. What did you do with your Renault?

With the Renault, I held down the open/close button while turning the ignition on, but yours may be different. Given you had coding done and now the sunroof is totally dead, I'd suggest going to someone who knows these Mercedes systems. It could be a simple recalibration, but best not to risk damaging the sunroof mechanism further. I was just sharing to see if this was likely the same problem.

I took your advice and went to a workshop. The coding had scrambled the sunroof module's settings. They ran a diagnostic and reinitialized the system. Now the sunblind and convertible top are working perfectly again. The cost was 75€.