Galaxy Rear Window Heating Issue

Interesting. The rear window heating and reduced windshield heating performance, coupled with an error code, does point to a potential power supply issue. Have you checked the battery's voltage, particularly under load? Modern cars, especially hybrids, rely heavily on stable voltage, and seemingly unrelated systems can act up if the battery is weak.

Thanks for the quick reply! By 'under load,' what exactly do you mean? Should I test it while the engine is running, or with things like the headlights and heating turned on? And what voltage am I looking for as a minimum?

Under load means testing the battery voltage while it's supplying power to other components. Ideally, test it with the engine off, but with several electrical consumers active – headlights, interior fan, and heated windows if possible (though yours isn't working). A healthy battery should maintain above 12V under these conditions. Given the symptoms and error code, a heavily discharged or defective battery is a strong possibility. If the voltage drops significantly below 12V, it's definitely suspect. While troubleshooting further might be possible, I would suggest you see a professional workshop about this issue. It could be something else but I'd guess they will recommend replacing the battery.

Alright, thanks a lot for the detailed explanation! I took it to a local garage, and you were spot on - the battery was heavily discharged and failing. They replaced it for 290€, and now the rear window heating is working perfectly again, and the windshield heating is back to its old self. Appreciate the help!