Mini Cooper Diesel Issue Preheating Lamp Stays On

Sounds like a familiar headache. I had a similar issue with my old Passat a few years back. The preheating lamp staying on, engine light popping up, the whole nine yards. Though I didn't notice the smoke you're describing. Have you checked the cable and plug connections to the control unit yourself? That's usually the first suspect.

Yeah, I gave the connections a quick look, didn't see anything obvious like a completely severed wire, but I'm no electrician. When you had the Passat issue, did you end up diagnosing it yourself, or did you take it straight to a mechanic? Any specific areas on the cable I should be focusing on?

I fiddled with the Passat for an afternoon, but car electronics aren't really my forte. Ended up taking it to my usual workshop. They confirmed it was a faulty control unit in the ignition system. Given the smoke issue, it might be a bit more complex than just a loose wire. I'd advise getting it properly diagnosed. Could save you some time and potential headaches down the road.

Just wanted to close the loop on this one. Took it to the shop like you suggested. Turns out it was exactly what we suspected, a defective part in the preheating control unit and corroded cable. 95€ later and she's running smooth! Thanks for the assist!