SMAX preheating lamp issue

Hey, that sounds like an electrical fault. Have you checked the cable and plug connections of the preheating control unit? Those can sometimes be the culprit, causing all sorts of weird issues with the ignition system and vehicle heater.

Thanks for the tip! Where exactly is the preheating control unit located? And is it something I could realistically check myself, or am I better off taking it to someone who knows what they're doing?

It's usually near the engine block, but honestly, if you're not super confident with electrics, it might be best to take it to a workshop. Fiddling with it yourself could cause more problems. They should be able to diagnose it properly.

Thanks again for the advice! I took it to a workshop, and you were spot on – it was a defective cable or plug connection to the preheating control unit. Cost me 95€ to fix. Appreciate the help!