Mercedes V Klasse Diesel Preheating Lamp Issue

I had a similar issue on my old BMW 3 series diesel. The preheating lamp stayed on, plus I noticed some engine misfire, especially during cold starts. Did you check the glow plug relay? That was my culprit initially.

Thanks for the info. The glow plug relay was not checked specifically. Is it typically straightforward to diagnose a faulty relay, or does it require specialized tools and diagnostic procedures?

For me, the relay diagnosis involved a multimeter to check for continuity and voltage. If you're not comfortable with that, I'd advise getting it checked professionally. Persisting with a faulty glow plug system can affect engine combustion efficiency and trigger the engine light. A check engine is something nobody wants.

Appreciate the confirmation. I'm proceeding to the workshop for a comprehensive check, including the glow plug relay. I will post the resolution. The cost was 440€ with glow plug replacement and error memory deletion.