Tourneo rear window heating failure

Interesting problem! I had a similar issue with my old Renault Scenic. The rear defroster just wouldn't kick in. Did you check the battery's health? A discharged or defective battery can cause weird electrical gremlins.

Battery, huh? I wouldn't have thought of that. The car starts fine, but maybe it's not delivering enough juice for the heating element. Did yours also start fine, even with the rear defroster not working? Was the battery the definite cause?

Yes, the car started without any problem. It was only when the heating load was higher that problems occurred. Think of it as trying to run too many appliances on a single extension cord. In my case, after changing the battery the windshield heating worked as expected. Based on those error codes and symptoms, I really believe you may want to have it checked in the workshop.

I had the battery tested, and you were spot on. It was heavily discharged and causing chaos. A new battery and 290€ later, the rear window is toasty again! You saved me hours of fruitless troubleshooting.