P0380 — Glow plug or heater circuit malfunction detected
The engine control unit detected a problem with the glow plug or heater circuit that helps start a diesel engine in cold conditions. This code appears when the circuit is open, shorted, or the glow plugs are not heating properly.
Common causes
The cause is almost always one of a few things. Here they are — P0380 rarely comes from anything outside this list:
- Faulty or worn glow plugs
- Damaged glow plug relay or control module
- Broken or corroded wiring/connectors in glow plug circuit
- Blown fuse related to glow plug system
Where to start
In the order a sensible mechanic would work — the cheap checks first, the expensive replacements only after:
- Check and replace blown fuses in glow plug circuit
- Inspect and repair wiring and connectors for damage or corrosion
- Test glow plug relay and replace if faulty
- Test glow plugs individually and replace any that fail
That is what holds for P0380 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.
Why TorqFix for your car?
Above is what the code means and why it appears. TorqFix goes further — it gives you specific procedures, torque values, wiring diagrams and pinouts for your exact engine, not generic steps for every car. Real workshop data (127,000+ diagrams, 10,000+ procedures), interpreted by AI in your language.
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Code breakdown
🔧 Related repair procedures
- AUDI: Removing and installing ignition coils with output stages
- AUDI: Removing and installing ignition coils with output stages, cylinder bank 2 (left-side)
- VW: Checking ignition coils with output stage
- AUDI: Checking ignition coils and output stages
- AUDI: Injection and ignition system (8-cyl. 5-valve injection engine) — Removing and installing ignition coils
- AUDI: Removing and installing ignition coils N323/N324/N325/N326 (cylinder bank 2 left-side)
- AUDI: Removing and installing ignition coils with output stages, cylinder bank 1 (right-side)
- AUDI: Removing and installing ignition coils N70/N127/N291/N292 (cylinder bank 1 right-side)
- AUDI: Removing and installing ignition coils with output stage
- VW: Removing and installing ignition coils with output stages
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
The same code can mean different things on different makes. Match the meaning to your make before acting on it.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
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