OBD-II · Engine and powertrain (P)
P0382
Glow plug/heater circuit B fault
What it means
Glow plug circuit B has a fault. Which plugs or relay belong to circuit B depends on the car.
Symptoms
- harder starting when cold
- rough running and white smoke for the first moments after a cold start
- glow plug light may flash
- possibly no symptoms in warm weather
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | failed glow plug(s) on circuit B |
| 02 | glow plug relay or module output fault |
| 03 | blown fuse |
| 04 | wiring or connector damage |
What to check, step by step
- 01Identify circuit B in the wiring diagram.
- 02Measure resistance or current of the glow plugs on that circuit.
- 03Check fuse, relay/module supply and wiring.
- 04When replacing glow plugs, work on a warm engine with the correct torque; if one feels seized, stop - a snapped glow plug means removing the cylinder head or drilling it out.