Citan transmission problems

Sounds frustrating! I had similar transmission problems with my old Renault Megane a few years back. It wasn't the paddle shifters specifically, but the gearbox was behaving erratically, shifting poorly and sometimes getting stuck. The mechanic suspected a faulty car computer, specifically something related to transmission control. Did you check the wiring harness going to the transmission control unit? Sometimes a loose or corroded connection can cause these kinds of issues before you start suspecting the control module itself.

Thanks for the insight! I haven't checked the wiring harness yet, but that's a good point. Where exactly is the transmission control unit located? I'll try to inspect the connections myself before taking it in, anything else I should look for?

On my Renault, the control unit was tucked away near the gearbox itself, but I am unsure about Mercedes. Honestly, if you're hearing grinding noises, and the error codes point to the control module, it's probably best to get it checked by a workshop. They'll be able to diagnose it properly and confirm if it's a defective unit or something else causing the transmission problems.

Appreciate the advice. I took it to a trusted mechanic, and they confirmed it was indeed the transmission control unit. They replaced it, and after recalibrating everything, the Citan is shifting smoothly again. Cost me almost exactly 1000€, as I feared. Thanks again for your help!