Urgency: Low
Glow Plug Light (Diesel)
This is usually informational. Address it at your convenience.
What the Glow Plug Light (Diesel) Means
The glow-plug light on your diesel your car is your cue to wait a couple of seconds before starting in cold weather. A flashing light after the engine is running, however, indicates a fault the ECU wants checked.
Common Causes
- Normal pre-heat cycle (steady, brief)
- One or more failed glow plugs
- Glow plug relay fault
- Crankshaft/camshaft sensor issue
- Related engine management fault
How to Fix It
- At cold start, wait for the light to go out before cranking
- If it flashes, scan for glow-plug and engine codes
- Test each glow plug for resistance/continuity
- Replace failed plugs (ideally as a set) and check the relay
- Clear codes and confirm easy cold starts
Related DTC Codes
| Code | Meaning |
|---|---|
P0335 | Crankshaft Position Sensor Circuit The crankshaft position sensor signal is faulty, which can cause stalling or a no-start condition. |