Peugeot 308 Auxiliary Heater Problem

I had a similar problem with my Opel Astra, though not exactly the same symptoms. Turned out to be a faulty glow plug relay. Have you checked the relay and the wiring to the heater? Coolant leak could also affect heater performance.

Thanks. How did you diagnose the faulty relay in your Astra? Was there a specific procedure, or was it a process of elimination?

The mechanic used a multimeter to test the relay and found it wasn't providing power to the glow plugs. Given your error code, a workshop diagnostic check is best. I paid around 350€ for parts and labor.

Thanks for the advice. I took it to a workshop and it was a defective glow plug, like I thought. Repair cost 440€. Thanks again.