XC90 Diesel Glow Control Unit Issue

I'm having trouble with my 2007 Volvo XC90 diesel. It has about 97840 km on it. The preheating lamp stays on after the engine starts, the check engine light is on, and it smokes when I accelerate. Tests suggest a bad glow control unit, maybe a bad cable or plug. Any ideas or what a reasonable repair cost would be?

4 comment(s)

I've seen something similar in my XC90. Sounds like it might be a glow plug issue. Is the engine running rough at all? It could just be a faulty sensor giving the wrong readings. Check the connections before replacing the whole unit.

Thanks! The engine idles smoothly. Could a faulty glow control unit alone cause these symptoms? I'm wondering if they're all connected. Where exactly are the connections I should check?

Yes, a faulty glow control unit could cause those symptoms. The glow plugs don't heat up properly, hence the smoke and engine light. You'd have to check the Engine control unit itself or go to the workshop. I would get a professional opinion.

Thanks! I took it to a local workshop, and the glow control unit was defective because of a corroded connector. The repair was about 95€, including parts and labor. Your advice helped a lot!

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