P0380Glow Plug/Heater Circuit A
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P0380 concerns glow plug circuit A – depending on the manufacturer the first group of plugs, glow relay 1 or feedback line A of the glow plug control module. Saab's 3.0 TiD (9-5, 2002) has two feedback lines from the control module; if line A at the engine module stays above 4.0 V for more than 3 s while glowing, the module is reporting a plug or circuit fault, checked once per drive cycle with the warning lamp on. In Saab's 1.9 TiD (EDC16) the glow plug control module drives two pairs of plugs, monitors them itself and reports faults over a diagnostic line that should switch inversely to the activation line. The 2010/11 Saab 9-5 2.0 TiD sets P0380 for implausible feedback or a missing supply of the module, there without check engine light. Newer GM and Ford diesels report single plugs under P0671 ff instead.
- What you may notice
- Hard starting when cold, long cranking
- White or blue smoke and rough running after a cold start
- Glow plug light or check engine light on or flashing
- Likely causes
- LikelyGlow plug(s) in circuit A burnt out
- PossibleGlow plug control module or glow relay faulty
- PossibleWiring or connector fault (feedback line, plug connector, supply)
- RareMissing battery or ignition supply of the control module (fuse)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.