Quest rear window heating malfunction

Those symptoms suggest a potential power supply problem. Have you checked the battery's condition? A heavily discharged or defective battery can trigger those errors and affect heating functions.

Thanks, I had it tested yesterday and it seemed fine. I wanted to avoid unnecessary workshop visits. If it might still be the battery, maybe it needs another better test?

Even with a seemingly 'fine' test, the battery might still be the culprit, especially with those combined symptoms. However, given the stored error, it's worth a professional diagnosis. Expect a bill around 290€, depending on the fault and the shop's labor rates.

Understood, I appreciate your input. I followed your advice and had it checked at the workshop. The battery was indeed the issue. Thank you for pointing me in the right direction.