P0380
Glow Plug/Heater Circuit "A"
- Severity
- Low
- Driving
- Drivable — book it in
A fault in glow plug or heater circuit "A". Glow plugs preheat the combustion chambers of a diesel engine so it will start when cold. A fault here often goes unnoticed in warm weather and then becomes obvious on the first cold morning, when the engine cranks for a long time, starts roughly, and produces white smoke.
Possible causes
- CommonOne or more failed glow plugs
- CommonFailed glow plug relay or control module
- CommonCorroded connections at the glow plugs
- PossibleBlown fuse on the glow plug circuit
- PossibleDamaged wiring in the glow plug harness
What you might notice
- Hard starting when cold
- White smoke on a cold start
- Rough running for the first minute from cold
- Glow plug light behaving oddly
- No symptom at all in warm weather
What to check, in order
- Test in cold weather, or at least on a fully cold engine. In summer a diesel will often start acceptably with several dead glow plugs, which is why these faults go unnoticed.
- Measure each glow plug individually. They usually fail one at a time, and the code may be set by just one of them.
- Check the relay or glow plug control module and the fuse.
- Inspect the connections at the plugs for corrosion - they sit in a hot, dirty part of the engine.
- Be aware that seized glow plugs are common on high-mileage engines and can break off during removal. That turns a cheap job into an expensive one, so it is worth knowing before starting rather than halfway through.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Ignition system or misfire
P0300P0301P0302P0303P0304P0305P0306P0307P0308P0309P0310P0311P0312P0313P0314P0315P0316P0317P0318P0319P0320P0321P0322P0323P0324P0325P0326P0327P0328P0329P0330P0331P0332P0333P0334P0335P0336P0337P0338P0339P0340P0341P0342P0343P0344P0345P0346P0347P0348P0349P0350P0351P0352P0353P0354P0355P0356P0357P0358P0359P0360P0361P0362P0363P0364P0365P0366P0367P0368P0369P0370P0371P0372P0373P0374P0375P0376P0377P0378P0379P0380P0381P0382P0383P0384P0385P0386P0387P0388P0389P0390P0391P0392P0393P0394