P0380
Fix within a few daysGlow Plug/Heater Circuit 'A' Malfunction
Code P0380 means your diesel's glow plug system has a fault. Common causes: Bad glow plugs (60%), faulty glow plug control module (30%). Drivability: Yes, safe to drive, but fix soon. Repair cost: $120-$400 DIY, $300-$800 professional.
Can I Drive With P0380?
Yes, safe to drive
No restrictions in warm weather. In cold weather, expect hard starting or no-start conditions.
Stop driving immediately if: Engine will not start at all, excessive white smoke, or other engine warning lights illuminate.
Symptoms of P0380
- 1Hard starting, especially in cold weather
- 2Engine cranks longer than usual before starting
- 3Rough idle immediately after a cold start
- 4White smoke from the exhaust on cold start
- 5Check Engine Light is on
Common Causes of P0380
Parts most likely causing this code, ranked by probability
One or more glow plugs have failed, preventing proper heating of the combustion chamber for cold starts.
60% of P0380 cases are fixed by replacing glow plugs
The control module or relay responsible for powering the glow plugs has failed, preventing them from activating.
30% of P0380 cases are fixed by replacing the glow plug control module or relay
Damaged wiring or corroded connectors in the glow plug circuit prevent power from reaching the glow plugs or the control module.
8% of P0380 cases are fixed by repairing wiring or connectors
A blown fuse in the glow plug circuit cuts off power to the system.
2% of P0380 cases are fixed by replacing a blown fuse
Check These First (Before Buying Parts)
- Check for any other glow plug specific codes (P067X) which pinpoint individual cylinder issues.
- Visually inspect the wiring harness and connectors leading to the glow plugs and the glow plug control module for any obvious damage or corrosion.
- Check the glow plug system fuse(s) in your vehicle's fuse box.
How to Diagnose P0380
- 1Scan for additional glow plug specific codes (P067X for individual glow plugs).
- 2Visually inspect all glow plug wiring and connectors for damage, corrosion, or loose connections.
- 3Test the resistance of each glow plug using a multimeter; readings outside specifications indicate a bad glow plug.
- 4Check for power and ground at the glow plug control module and at the glow plugs when commanded on.
- 5Inspect the glow plug system fuse(s) in the fuse box.
P0380 on Popular Vehicles
Ford F-150/Super Duty (Powerstroke)
2003-2024P0380 on Powerstroke engines frequently points to either failed glow plugs or a faulty Glow Plug Control Module (GPCM). The GPCM is a common failure point on 6.0L and 6.4L engines.
75% fixed by replacing glow plugs or GPCM
Chevrolet Silverado/GMC Sierra (Duramax)
2001-2024Duramax engines commonly experience P0380 due to individual glow plug failures. The glow plug controller (GPCM) can also fail, but individual glow plugs are a more frequent cause.
70% fixed by replacing glow plugs or GPCM
Ram (Cummins)
2007-2024On Cummins engines, P0380 is often caused by failed glow plugs, particularly as the engine ages. The glow plug relay or module can also be a cause, but glow plug replacement is the most common fix.
65% fixed by replacing glow plugs or GPCM
Frequently Asked Questions
What does P0380 mean?
P0380 indicates a malfunction in the glow plug/heater circuit 'A'. This means the engine's computer has detected an issue with the system that preheats the combustion chambers in your diesel engine for cold starts.
Can I drive with P0380?
Yes, you can drive safely, especially in warmer weather. However, in cold temperatures, you will experience hard starting or a no-start condition. Fix this within a few days to prevent further issues.
Will P0380 clear itself?
No, P0380 will not clear itself. The underlying electrical or component fault must be repaired before the code will clear. You will need to fix the issue and then clear the code with an OBD-II scanner.
How do I fix P0380 myself?
Start by checking for blown fuses and inspecting wiring. Then, test the resistance of each glow plug with a multimeter. If a glow plug is bad, replace the faulty one or the entire set. If glow plugs test good, diagnose the glow plug control module or relay.
How much does it cost to fix P0380?
DIY repair costs for P0380 range from $120-$400, primarily for new glow plugs or a control module. Professional repair costs typically range from $300-$800, covering parts and labor.
P0380 keeps coming back - why?
If P0380 keeps returning, it means the root cause was not fully addressed. This often happens if you only replaced one glow plug when others were also failing, or if the glow plug control module is faulty but was overlooked during initial diagnosis.
Will P0380 fail emissions/smog test?
Yes, P0380 will cause your vehicle to fail an emissions or smog test. A Check Engine Light indicating a fault in the glow plug system is an automatic failure in states with OBD-II emissions inspections.
What's the difference between P0380 and P0670?
P0380 indicates a general malfunction in the glow plug/heater circuit 'A', meaning there's a problem somewhere in the system. P0670 specifically points to a fault in the Glow Plug Control Module circuit, indicating the issue is with the module itself or its wiring.
P0380 on Ford F-150/Super Duty (Powerstroke)
On Ford Powerstroke engines, P0380 is very common. Often, it's due to failed glow plugs, but the Glow Plug Control Module (GPCM) is also a frequent culprit, especially on 6.0L and 6.4L Powerstrokes. Always check the GPCM and its harness connections.
Questions to Ask Your Mechanic
Did you test the resistance of each individual glow plug?
Good answer: Yes, I tested all glow plugs and found cylinder X's glow plug was open/shorted. The others were within spec.
What did you find when testing the glow plug control module's operation?
Good answer: I confirmed the GPCM is receiving power and ground, but it's not sending voltage to the glow plugs when commanded on, indicating an internal fault.
Repair Cost Estimate
DIY Repair
Parts only
$120-$400
Shop Repair
Parts + labor
$300-$800
Save $180-$400 by doing it yourself
Difficulty
intermediate
Time
2-4 hours
Intermediate - requires a multimeter for testing, specific glow plug sockets, and careful handling to avoid breaking glow plugs in the cylinder head.
Cost of Waiting
Ignoring P0380, especially in cold climates, leads to increasingly difficult starting, excessive cranking, and increased strain on your starter motor and battery. A $150 glow plug replacement now prevents a potential $500 starter replacement later.
While You're In There...
Apply to electrical connectors to prevent corrosion and ensure good contact, especially in harsh engine environments.
Apply to glow plug threads to prevent them from seizing in the cylinder head, making future removal much easier.
Tools You'll Need
- OBD-II Scanner
- Multimeter
- Socket set (including deep sockets for glow plugs)
- Torque wrench
- Basic hand tools
P0380 is a very common code on diesel engines. The repair is usually straightforward, and once fixed, your engine will start reliably again, even in the coldest weather.
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Your Next Steps
Step 1: Use an OBD-II scanner to check for any additional glow plug codes (P067X). These codes will tell you exactly which glow plug is faulty.
Step 2: If no specific glow plug codes are present, visually inspect the glow plug control module and its wiring for damage. Then, test the resistance of each glow plug with a multimeter. A reading outside of specifications (usually 0.5-2.0 ohms) indicates a bad glow plug.
Step 3: If glow plugs test good, test the glow plug control module for proper operation. If the module is not sending power to the glow plugs when commanded, it needs replacement. Parts you'll likely need: A set of glow plugs (4-8 depending on engine), or a new glow plug control module.