Partner preheating lamp and check engine light

I had a similar issue with my Partner. Is it possible the preheater is the culprit?

You had the same symptoms? Preheating lamp stuck on, check engine light, and smoke? And it was the preheating unit itself? Did you check any other components?

Correct. Similar symptoms, same preheating unit issue. I'd recommend getting it checked by a workshop, just to be sure.

Thanks so much for the advice! I booked it in, and you were spot on – the preheating control unit was indeed defective! The cable and plug connections looked corroded. 95€ later, and she's running smooth again. Appreciate the help!