📌 What does the P0380 code mean?
The P0380 code is a generic OBD-II code related to the glow plug system in diesel engines. It indicates that the PCM (powertrain control module) has detected an electrical fault in the circuit “A” of the glow plug system, often due to a faulty glow plug or a wiring issue.
⚠️ Do not confuse with the P0382 code, which concerns the circuit “B” of the glow plug system.
⚠️ Common symptoms:
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Engine light (MIL) on
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Glow plug indicator stays on abnormally long or continuously
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Hard starting, especially in cold weather
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Possible white smoke at startup
🔍 Possible causes:
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Glow plug burned out or worn
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Fuse blown
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Glow plug relay faulty
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Glow plug control module defective
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Wiring or connectors damaged (short circuit, break, corrosion)
🛠️ Diagnostic steps and possible solutions:
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Check the fuses related to the glow plugs, replace if necessary.
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Test the glow plug relay: if it’s faulty, replace it.
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Visually inspect the connectors, wiring, and glow plugs for signs of corrosion, broken wires, or loose connectors.
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Measure the resistance of each glow plug using a multimeter (DVOM). A functioning glow plug typically shows low resistance (often < 1 ohm).
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Check the supply voltage at the glow plug terminals when the ignition is on.
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Practical test: remove the glow plug and briefly supply it with 12V (quick test with caution) → if it glows red quickly, it’s working.
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Consult the technical service bulletins (TSB) for your vehicle: some models have known issues.
🧰 Practical tip:
Always replace glow plugs in pairs or as a full set to ensure uniform operation.
📚 Glow plug related codes:
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P0381 to P0384: various circuit failures
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P0670 to P0682: specific faults per cylinder
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P068X: issues with glow plug relays or modules