Bipper AC failure

Sorry to hear about your AC woes. The error code plus the other symptoms definitely point to a problem with the AC system. Has the system been tested for refrigerant pressure and leaks? Low refrigerant can prevent the compressor from engaging, and some cars have a safety switch that disables the AC to protect the compressor. I would start there, but AC compressor issues on those can also stem from electrical problems.

I haven't had the system pressure tested specifically. Where exactly would I find that safety switch you mentioned, and how would I test if it's the culprit? Also, if it is electrical, what components should I check first?

Okay, the safety switch is usually near the compressor or the receiver drier. You can't really 'test' it without proper equipment, but a mechanic can easily bypass it to see if the compressor kicks on, which would indicate a faulty switch. Given the error code, and the fact that it's all happening at once, it's quite possible that the air conditioning control unit is defective. To be honest, at this point, I'd take it to a workshop specializing in auto AC repair. They have the tools to properly diagnose the electrical side and check for leaks. Messing with refrigerant yourself isn't a good idea, and could be dangerous.

Thanks so much for your advice! I took it to a local shop, and after a full diagnostic, they confirmed that the air conditioning control unit was defective, just like you suspected. The final repair cost, including a new control unit and labor, came out to 980€. Ouch! But at least it's fixed now. Thanks again!