P02CF

What it means

P02CF means the engine control unit has learned an offset correction for the cylinder 2 fuel injector (bank or injector A circuit) and that correction has reached its maximum allowed limit. The control unit trims each injector to match its actual delivery against what it expects, and it can no longer compensate for the difference. This is most often seen on direct injection systems, and the exact learning method depends on the engine.

Symptoms

• Engine management light on
• Rough idle or uneven running, especially when cold
• Misfire or hesitation on cylinder 2
• Poor fuel economy
• Hard starting or extended cranking
• Loss of power or reduced performance

Possible causes

• Worn, sticking or leaking cylinder 2 fuel injector delivering more or less fuel than commandedlikely
• Carbon or deposit build-up on the injector tip or in the combustion chamber of cylinder 2likely
• Wiring or connector fault on the cylinder 2 injector circuit (high resistance, corrosion, poor pin tension)possible
• Low or unstable fuel rail pressure affecting injector delivery, for example a weak pump or pressure regulation faultpossible
• Air leak, compression loss or mechanical fault on cylinder 2 causing the control unit to over-correctpossible
• Fault within the engine control unit injector driver or an outdated calibration where the manufacturer has issued an updaterare

How to diagnose

1. Read all stored and pending codes plus freeze frame data, noting engine temperature, load and fuel trims when the code set
2. Check for other related codes such as misfires, rail pressure or fuel trim faults, and deal with those first
3. Inspect the cylinder 2 injector connector and wiring for damage, corrosion, chafing and a secure fit
4. View live data for injector offset or learned correction values and fuel trims, comparing cylinder 2 with the others if the system allows
5. Check fuel rail pressure against specification at idle and under load, and check fuel quality and filter condition where applicable
6. Carry out a cylinder balance or misfire test and check compression and for intake air leaks on cylinder 2
7. Test the injector electrical resistance and operation, following the manufacturer procedure for your engine
8. After repair, clear the codes and perform the relevant learning or adaptation procedure, then road test and recheck

How to fix

• Replace the cylinder 2 injector if it is faulty, and carry out any required injector coding or learning afterwards
• Clean or remedy carbon deposits using a suitable manufacturer-approved procedure
• Repair or replace damaged wiring, terminals or the connector on the injector circuit
• Correct fuel pressure faults by repairing or replacing the failed fuel delivery or pressure control component
• Repair the mechanical or air leak problem on cylinder 2 that is causing the over-correction
• Apply a manufacturer calibration update if one is known to address this fault

Can I keep driving?

Nearby codes

• P02CEGenericCylinder 2 Fuel Injector A Offset Learning At Min Limit
• P02D0GenericCylinder 3 Fuel Injector A Offset Learning At Min Limit