Cylinder 9 injector partially blocked by deposits or contamination; Injector internal wear or a sticking pintle or needle reducing flow; Low fuel pressure or restricted fuel supply affecting the injector's delivery; Wiring, connector or terminal fault on the cylinder 9 injector circuit giving weak or intermittent operation; Intake air leak or vacuum leak near cylinder 9 causing a lean reading that is wrongly attributed to the injector; Fault in the engine control unit injector driver; Poor quality or contaminated fuel.

P02BC

Cylinder 9 - Injector Restricted.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
BC: FaultThe specific fault in that area

What it means

P02BC is the generic code for a restricted fuel injector on cylinder 9. The engine control unit has judged that the cylinder 9 injector is delivering less fuel than it commands. It usually reaches this conclusion from fuel trim, cylinder balance or exhaust oxygen sensor data for that cylinder or its bank. The code only applies to engines with at least nine cylinders, and the cylinder numbering and detection method depend on the manufacturer and engine.

Symptoms

Rough idle or misfire felt mainly at low speed
Hesitation or reduced power under load
Malfunction indicator lamp on
Poor fuel economy
Hard starting or uneven running when cold
Lean running on one bank

Possible causes

Cylinder 9 injector partially blocked by deposits or contaminationlikely
Injector internal wear or a sticking pintle or needle reducing flowlikely
Low fuel pressure or restricted fuel supply affecting the injector's deliverypossible
Wiring, connector or terminal fault on the cylinder 9 injector circuit giving weak or intermittent operationpossible
Intake air leak or vacuum leak near cylinder 9 causing a lean reading that is wrongly attributed to the injectorpossible
Fault in the engine control unit injector driverrare
Poor quality or contaminated fuelrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting load, engine temperature and fuel trim values when the fault was set
Confirm which physical cylinder is cylinder 9 for this engine using the manufacturer's firing order and numbering information
Check for other fuel trim, misfire or lean codes that point to a wider problem such as an air leak or low fuel pressure
Inspect the cylinder 9 injector connector, terminals and wiring for damage, corrosion, looseness or heat damage
Look for intake leaks, split hoses and loose connections on the intake side near cylinder 9, and check for exhaust leaks ahead of the oxygen sensors
Check fuel pressure and delivery against the manufacturer's specification, which varies by engine and fuel system type
Measure the injector's electrical resistance and observe its drive signal, then compare with the specification and with neighbouring injectors
Run an injector balance or flow test, or use live data on cylinder contribution, to confirm that cylinder 9 delivers less fuel than the others

How to fix

Clean or replace the cylinder 9 injector if it is blocked or its flow is out of specification
Repair or replace damaged wiring, terminals or the connector on the injector circuit
Restore correct fuel pressure by addressing the fuel filter, pump or pressure regulator, depending on what the engine uses
Repair any intake or vacuum leaks that are skewing the fuel trim
Drain and replace contaminated fuel, then recheck the injector after refuelling
Replace the engine control unit only after all other causes are ruled out and the driver fault is confirmed

Can I keep driving?

Medium severity

The car can usually be driven short distances, but book it in soon. A lean or misfiring cylinder can overheat the catalyst and may damage the engine if it is ignored, so avoid heavy loads and stop if the engine runs very roughly or the warning lamp flashes.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.