C1 Rear Ventilation Flap Error

Sounds familiar! I've got a C1 myself, and I had similar air conditioning issues last summer. The error codes pointed to the rear ventilation flap too. Did you check the wiring harness behind the glove box? Seems to be a common place for connections to wiggle loose.

Behind the glove box, you say? Is that a huge job to get to? I'm reasonably handy, but I don’t want to start ripping things apart if it's a nightmare. How much disassembly are we talking here? Any special tools needed?

Yeah, behind the glove box. It's not too bad, just a few plastic clips and screws if I remember correctly. Nothing special tool-wise. But honestly, if you're getting error codes and the AC is totally out, it might be worth getting it checked professionally. I ended up biting the bullet and taking mine to a workshop.

I think I'll take your advice and get a pro to look at it. Turns out the rear ventilation flap cable was indeed defective, as you suspected. Cost me 95€ to repair. Cheers for pointing me in the right direction!