P03BC: Combustion in cylinder 4 is not performing as expected
Combustion in cylinder 4 is not performing as expected. Spark plugs or glow plugs, coils, injectors and air intake need checking first.
| Code | P03BC |
|---|---|
| System | Engine and transmission |
| Group | P03xx, Ignition and misfires |
| Type | Generic: it means the same on every make |
How to read and clear P03BC 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 P03BC with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
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 an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P03B8 The cylinder 4 pressure is below normal
- P03B9 The cylinder 4 pressure is above normal
- P03BA The cylinder 4 pressure variation gives a lower signal than normal
- P03BB The cylinder 4 pressure variation gives a higher signal than normal
- P03BD The cylinder 5 pressure sensor has an electrical fault
- P03BE The cylinder 5 pressure sensor gives readings outside the normal range
- P03BF The cylinder 5 pressure sensor gives a lower signal than normal
- P03C0 The cylinder 5 pressure sensor gives a higher signal than normal
- P0300 Random or multiple cylinder misfire
- P0301 Misfire detected in cylinder 1
- P0302 Misfire detected in cylinder 2
- P0303 Misfire detected in cylinder 3
What does code P03BC mean?
Combustion in cylinder 4 is not performing as expected. Spark plugs or glow plugs, coils, injectors and air intake need checking first.
How do you clear P03BC?
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, P03BC comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
