Viano automatic transmission problem

I understand your frustration. I had a similar problem with my older Volvo. The symptoms you describe, particularly the engine not starting and the transmission issues, match what I experienced. In my case, the cause was a faulty transmission control module. Have you inspected the gear linkage for damage or misalignment? Check the automatic transmission fluid level and condition as well. Low or contaminated fluid can cause shifting problems. I am concerned with the automatic transmission on your car.

Thanks for the reply! The gear linkage looks okay, and I checked the transmission fluid level. It was a bit low, but topping it off didn't help. Is the 'transmission control module' the same as the control unit the mechanic mentioned? Where is that located, and could I check it myself, or is it better left to a professional? Did you have any slipping issues?

Yes, the transmission control module is the same as the control unit your mechanic mentioned. I cannot provide specific location details for your Mercedes Viano, but it is usually within or near the transmission. Given the complexity, I advise against attempting repairs yourself unless you have the expertise and tools. I had slippage that became progressively worse. Considering the potential repair cost, get a professional diagnosis to determine the cause. A workshop should be able to assess it.

Okay, thanks. I took it to a workshop, and they confirmed it was the transmission control unit. They quoted me around 1000€ to replace it. Hopefully, that resolves the issue. Appreciate the help!