P0380Powertrain
Powertrain · SAE
Glow Plug Heater Circuit A
Meaning
The glow-plug circuit (diesel) is faulty. The preheating needed for cold starting is compromised.
Common causes
- One or more failed glow plugs
- Faulty glow-plug relay or control module
- Open, shorted or corroded wiring/connector
- Faulty supply or ground for the glow-plug circuit
- Glow-plug resistance out of specification
- Blown glow-plug circuit fuse
Symptoms
- Hard cold starting
- Rough idle when the engine is cold
- White smoke on cold start-up
- Preheat/glow-plug light or check-engine light on
- Rough running until the engine warms up
Severity
Moderate: the vehicle runs once warm, but cold starting may be difficult.
What to do
- Read the codes and check the glow-plug circuit status in live data
- Measure each glow plug's resistance and identify any out of specification
- Check the relay/control module, supply, ground and fuse
- Replace faulty glow plugs and the control module if it is not driving them correctly