GrandlandX Rear Window Heating Issue

Sounds familiar! I've had similar issues with my GrandlandX. Rear window defroster packed in, and the front demister seemed less effective too. An error code makes it more likely to be electrical though. Have you had your battery checked recently? A weak or failing battery can cause all sorts of weird electrical gremlins. The defroster pulls a lot of power, so a dodgy battery could definitely cause this.

Thanks, that's helpful. No, I haven't checked the battery specifically. Is it likely to affect just the rear window and windshield, or would I see other symptoms too?

Well, a low battery can cause all sorts of unpredictable issues because modern cars rely so heavily on stable voltage for all of their computerized systems. You might see other things like the start/stop system not working, or maybe even flickering lights. BUT, the rear window heater and windshield heater failing are often the first noticeable things as they draw a lot of juice. Honestly, get the battery properly tested. If it's not that, at least you've ruled it out. If it is, that is the cheapest fix you will ever get on these vehicles!

Thanks for the advice. Took it to a workshop, and you were spot on – the battery was heavily discharged and defective. Replacing it fixed the rear window heating issue. Cost me 290€, but at least it's sorted.