P02C2
Cylinder 11 - Fuel Trim at Max Limit.
- 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)
- C2
- FaultThe specific fault in that area
What it means
P02C2 means the engine control unit has found that the fuel trim correction for cylinder 11 has reached its maximum limit. The unit is adjusting the fuel delivery to that one cylinder as far as it is allowed to, yet still cannot bring the air-fuel mixture back to target. This points to a fault affecting that cylinder, such as a fuelling, air or mechanical problem, and the code applies only to engines with at least eleven cylinders using individual cylinder trim.
Symptoms
- Engine management light on
- Rough running or a noticeable misfire at idle
- Reduced power and hesitation under load
- Poor fuel economy
- Rough or unstable idle
- Possible smell of fuel or raw exhaust
Possible causes
- Faulty or leaking fuel injector on cylinder 11 (clogged, stuck open or poor spray pattern)likely
- Damaged wiring, poor connector contact or high resistance in the injector circuit for cylinder 11likely
- Vacuum or intake leak affecting cylinder 11 only, such as a split manifold gasket or intake runner sealpossible
- Exhaust leak or fault close to the oxygen sensor covering cylinder 11, giving a false mixture readingpossible
- Mechanical problem in cylinder 11 such as low compression, a worn valve or a burnt valve seatpossible
- Faulty or contaminated oxygen sensor or air-fuel ratio sensor for the relevant bankpossible
- Fault inside the engine control unit driver circuitrare
How to diagnose
- Read all stored and pending codes and note the freeze frame data, including engine load, temperature and fuel trim values at the time the fault set.
- Check for other related codes such as misfires, other cylinder trim codes or sensor faults, and deal with those first as they may be the root cause.
- Visually inspect the injector wiring, connectors and earth connections for cylinder 11, looking for damage, corrosion, chafing or heat damage.
- Inspect the intake manifold, hoses and gaskets for leaks, and carry out a smoke test if a leak is suspected.
- Check live data for fuel trims and misfire counters, and compare cylinder 11 against the other cylinders on the same bank.
- Test the injector on cylinder 11 for correct resistance and operation, and check its drive signal, following the procedure for that engine.
- Inspect for exhaust leaks upstream of the relevant sensor and check the sensor response in live data.
- Carry out a compression or leak-down test on cylinder 11 if the fuelling and air side check out.
How to fix
- Clean or replace the faulty fuel injector on cylinder 11 as the test results indicate.
- Repair or replace damaged wiring, connectors or terminals in the injector circuit.
- Replace leaking intake gaskets, seals or hoses to remove the air leak.
- Repair the exhaust leak or replace the faulty oxygen or air-fuel ratio sensor.
- Repair the mechanical fault in cylinder 11, such as valve or sealing faults, once confirmed by testing.
- Clear the code after repair and road test to confirm the fuel trim has returned to normal.
Can I keep driving?
The car can usually be driven short distances to get it checked, but it should be looked at soon. A continuing misfire or over-rich running can damage the catalytic converter and cause further engine wear, so avoid heavy loads and stop if the engine runs very roughly or the warning light flashes.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.