Mercedes C Klasse climate control issues

Sounds like an annoying problem. Have you checked the temperature sensor readings with a diagnostic tool? Sometimes a faulty sensor can give incorrect data and cause the whole system to shut down, or send weird values to the control panel. I would try that before suspecting the entire climate control unit.

That's a good point about the temperature sensor. I didn't specifically log the sensor values. Where exactly is that temperature sensor located in the C Klasse's climate control system? I'm trying to avoid unnecessary disassembly, so any pointers on its location would be appreciated.

The temperature sensor is usually located near the blower motor or within the air duct system. Without knowing the exact sub-model of your C Klasse, I couldn't say exactly where it is. Given it's throwing a code and the system is completely unresponsive, it's likely a deeper electrical issue than just the sensor. I suggest seeking a professional diagnosis. Replacing parts without proper troubleshooting can get expensive. I wouldn't touch it yourself.

Thanks for the temperature sensor tip and caution, wise words. I took it to a workshop and you were right. Turned out to be a corroded connector in the climate control harness, just like the error suggested. Bill came to 95€, which included the diagnosis and connector replacement. Appreciate the help!