Insignia AUC Sensor Fault

Sounds familiar. Had a similar issue on my old Volvo, though it was the HVAC sensor there. Check the connector block to the AUC sensor itself. Use a multimeter to check the wiring too. Any sign of chafing or corrosion? They're often located in spots prone to damp.

Cheers. Good shout on the multimeter; I'll dig deeper. Was the Volvo thing just a bad connection then, or a duff sensor?

On the Volvo it was indeed a dodgy connector. Cleaned it up and packed it with dielectric grease. Though if you suspect the sensor itself is gone, testing resistance values should confirm it. I'm just cautious to say it's a DIY job, it might involve recalibrating the HVAC system. Therefore, visiting a workshop might be more appropriate here.

Spot on. Turns out a wire was loose and the plug connection was defective. Sorted it, now works like a charm. Cost me 95€ at the workshop. Thanks for the sanity check!