Cylinder 11 injector seat or nozzle leaking or stuck partly open; Carbon or debris preventing the injector from sealing fully; Internal injector fault such as a worn needle or failed seals; Fuel pressure too high due to a regulator or pressure control fault, causing injectors to leak; Injector wiring or connector fault causing incorrect injector operation; Outdated or faulty engine control unit calibration, where a known issue exists for the engine; Fault in the engine control unit injector driver.

P02C5

Cylinder 11 - Injector Leaking.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
C5: FaultThe specific fault in that area

What it means

P02C5 is the generic code for a leaking fuel injector on cylinder 11. The engine control unit has detected evidence that the injector is passing fuel when it should be closed, or that cylinder 11 is receiving more fuel than commanded. This is usually spotted through fuel trim, rail pressure decay or combustion monitoring, and the exact detection method depends on the engine. Cylinder 11 only exists on engines with 12 cylinders or more, so this code is rare.

Symptoms

Rough idle or misfire, especially on cylinder 11
Long cranking or hard starting after the engine has been standing, or when hot
Smell of fuel or black smoke from the exhaust
Increased fuel consumption
Malfunction indicator lamp on, possibly flashing under misfire
Fuel dilution of the engine oil, which may smell of petrol or diesel

Possible causes

Cylinder 11 injector seat or nozzle leaking or stuck partly openlikely
Carbon or debris preventing the injector from sealing fullylikely
Internal injector fault such as a worn needle or failed sealspossible
Fuel pressure too high due to a regulator or pressure control fault, causing injectors to leakpossible
Injector wiring or connector fault causing incorrect injector operationpossible
Outdated or faulty engine control unit calibration, where a known issue exists for the enginerare
Fault in the engine control unit injector driverrare

How to diagnose

Read all stored codes and freeze frame data, noting load, temperature and fuel trim values when the code set, and check for related misfire or fuel pressure codes
Check the manufacturer's service information for cylinder numbering and for known issues or bulletins on your engine
Inspect the cylinder 11 injector wiring and connector for damage, corrosion, chafing or poor pin tension
Check for fuel smell, wet injector seals or fuel around the injector, and check the engine oil for fuel dilution
Monitor live data for fuel trims, misfire counters and fuel rail pressure, and look for pressure decay after shutdown
Test fuel pressure and regulator or pressure control operation against specification
Carry out an injector leak-down or balance test on cylinder 11 using the procedure for your engine
Compare injector resistance and waveform with specification and with a neighbouring cylinder

How to fix

Replace the cylinder 11 injector if it is confirmed leaking, and adopt any coding or adaptation the manufacturer requires
Clean or replace the injector seals and correct any carbon build-up where the manufacturer allows it
Repair or replace damaged injector wiring or connectors
Repair the fuel pressure control fault if pressure is out of specification
Change the engine oil and filter if fuel dilution is found
Update the control unit software only where an outdated calibration is a documented cause for that engine

Can I keep driving?

High severity

Avoid driving until it is checked. A leaking injector can wash oil from the cylinder walls, dilute the engine oil and damage the engine or catalytic converter, so only drive it a short distance to a workshop if you must.

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