P0380: Glow Plug/Heater Circuit A Malfunction
Can you still drive? Yes, you can drive if the engine starts. However, cold starting will be difficult and extended cranking can wear the starter motor.
What Does P0380 Mean?
Code P0380 is specific to diesel engines and indicates a fault in the glow plug or intake air heater circuit. Glow plugs preheat the combustion chamber to help diesel fuel ignite during cold starts. When this circuit malfunctions, the engine may be extremely difficult or impossible to start in cold weather.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Failed glow plug(s)
- Faulty glow plug relay or control module
- Corroded or damaged wiring to glow plugs
- Blown glow plug fuse
- Defective glow plug timer
Symptoms
- Check engine light on
- Hard starting in cold weather
- White smoke on startup
- Extended cranking time
- Rough idle when cold
Diagnostic Steps
- 1Scan for additional glow plug related codes
- 2Test each glow plug individually for resistance using a multimeter
- 3Check the glow plug relay for proper operation
- 4Inspect wiring and connectors for corrosion or damage
- 5Verify power supply and ground to the glow plug circuit
- 6Test the glow plug control module signal
Recommended Parts & Tools
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $500 |
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Chat with AI About P0380Commonly Affected Vehicles
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Frequently Asked Questions
Do glow plugs only matter in winter?
Glow plugs are most critical in cold weather, but they also assist with combustion during normal operation. A faulty glow plug can cause rough running and increased emissions year-round.
How many glow plugs does my diesel engine have?
Diesel engines have one glow plug per cylinder. A 4-cylinder diesel has 4 glow plugs, a 6-cylinder has 6, and so on.
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