C70 Parking Heater Problem

Sounds familiar! I had a similar issue with my C70's auxiliary heater last year. It was acting like a moody teenager – refusing to cooperate. Did you check the temperature sensor? Sometimes it throws a wrench in the whole system.

Temperature sensor, eh? Where is that located, roughly? And what were the symptoms you experienced before you started troubleshooting?

Yeah, the temp sensor can be a pain. Mine was buried near the heater core, as far as I remember. My symptoms were exactly the same: parking heater wouldn't activate and had error codes stored. I'd suggest getting it checked out by a workshop, could be the glow plug like you said. Cost me around 440€ to fix.

440€! Ouch! Thanks for the heads-up. I'll take it in and brace myself. Sounds like I am in for an expensive visit.