Mercedes Citan door locking issue

I had a similar problem with my Citan. The symptoms you describe suggest a potential issue with the door sensor's contact signal. Have you noticed anything unusual from the car alarm, like intermittent activation or failure to disarm? What tests did you perform on the fuses? Ensure the wiring harness integrity, especially the plug connection, as this is a known failure point. A defective plug connection can disrupt the signal transmission.

When you had the issue, were all the doors affected, or just one? I didn't notice anything strange with the alarm itself, but I will keep an eye on it. What do you mean by 'specific tests' on the fuses? I just checked if they were blown. Is there more to it?

All my doors were affected simultaneously, indicating a central point of failure. For the fuses, a visual inspection is a good start, but use a multimeter to verify continuity. This ensures the fuse is functional. I recommend taking your Citan to a qualified workshop for a diagnostic assessment. A repair cost of 95€ seems reasonable for addressing a defective cable or plug connection.

I took it to a workshop as you suggested. It was indeed a defective plug connection in the wiring harness. They fixed it for 90€, cheaper than expected. Everything is working now.