P0381: Glow plug indicator light circuit fault
Fault in the dashboard glow plug warning light circuit. The car runs as normal, but the light no longer shows properly when it is ready to start.
| Code | P0381 |
|---|---|
| System | Engine and transmission |
| Group | P03xx, Ignition and misfires |
| Type | Generic: it means the same on every make |
| Can you keep driving? | Yes, no rush |
What P0381 means
On diesels, the coil-shaped light on the dashboard comes on with the ignition and goes out when the glow plugs are ready for starting. This code means the ECU has found a fault in the circuit that switches that light, not in the glow plugs themselves. Some manufacturers also use this light to warn of other engine faults.
Most common causes
- Poor contact at the instrument cluster or wiring connector
- Warning light wire broken or shorted to earth
- Blown bulb or LED
- Instrument cluster fault
- ECU or glow plug control unit fault
Symptoms
- Glow plug light does not come on with the ignition
- Light stays on all the time
- Engine warning light on
- No change in how the car drives
Can you drive with P0381?
Yes, no rush You can drive normally. When cold, wait a few seconds with the ignition on before starting, as the light will not tell you reliably.
How to check it
Turn the ignition on without starting and see whether the coil light comes on for a few seconds: if it never lights up, tell the garage, as that points to the light or its wiring rather than the glow plugs.
How to read and clear P0381 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0381 with this same explanation and whether it’s confirmed, pending or permanent.
With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.
Similar codes
- P0356 Ignition coil F circuit fault
- P0365 Camshaft position sensor B circuit fault (bank 1)
- P0366 Camshaft position sensor B signal out of range (bank 1)
- P0380 Glow plug circuit A fault
- P0382 Glow plug circuit B malfunction
- P0300 Random or multiple cylinder misfire
- P0301 Misfire detected in cylinder 1
- P0302 Misfire detected in cylinder 2
- P0303 Misfire detected in cylinder 3
P0381 is a generic code, so it means the same on any make, for example on BMW, Fiat, Ford, Mazda, Peugeot, Volkswagen. See what Final OBD does on your car in makes and models.
What does code P0381 mean?
On diesels, the coil-shaped light on the dashboard comes on with the ignition and goes out when the glow plugs are ready for starting. This code means the ECU has found a fault in the circuit that switches that light, not in the glow plugs themselves. Some manufacturers also use this light to warn of other engine faults.
Can you drive with P0381?
You can drive normally. When cold, wait a few seconds with the ignition on before starting, as the light will not tell you reliably.
How do you clear P0381?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0381 comes back.
Read it on your car
Final OBD reads the faults of every control unit for free, including each make’s own codes, and with Pro explains each one in plain English. Free clears engine faults at no cost.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com