C1 rough idle error code

I drive a C1 as well. The error code and uneven idling point towards a potential issue with the engine mount's electrical connection. Have you checked the cable and plug connection of the component itself? A defective connection there can wreak havoc.

Thanks! When you say 'checked', what exactly do you mean? I'm not mechanically inclined, any pointers on what to look for?

By 'checked', I mean a thorough visual inspection for any signs of damage, corrosion, or looseness. Consult the vehicle's repair manual for the exact location of the engine mount and its corresponding electrical connector. Carefully disconnect the plug, examine the pins for any deformation or oxidation, and ensure a secure and firm reconnection. Given the complexity of modern engine management systems and the mileage, it might be prudent to seek professional diagnostic assistance. A thorough inspection by a qualified technician can definitively confirm the issue and prevent potential consequential damage.

Thanks! I'm bringing it in. You were right, the cable or plug connection was defective. The workshop replaced it for 95€. Hopefully that fixes it!