Vectra climate control AUC sensor fault

Sounds familiar. Had something similar with my old Peugeot, though it was a petrol engine. The auto recirculation wasn't working right and it turned out to be a faulty HVAC sensor connection. Did you check all the connections to the sensor itself? That's where I'd start.

Yeah, I checked the obvious stuff, visually. Could be a broken wire I suppose. Was your Peugeot completely dead, like nothing at all, or just acting up? I get absolutely zero blower action.

Mine was intermittent at first, then completely dead. No fan, nothing. Given it's totally dead on yours, and you're getting that sensor fault, I'd say it's probably more than just a loose wire. Might be worth getting it properly diagnosed to avoid chasing ghosts.

Took it to the shop. You were right; it was the connection. They cleaned it up and tested the sensor. Works fine now. Cost me 95€ Thanks for the advice!