P02CFCylinder 2 Fuel Injector A Offset Learning At Max Limit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The engine module learns a small-quantity correction for each injector: on overrun it gives one injector a tiny test injection (GM about 1.5 mm³), measures the resulting crankshaft acceleration and corrects the injector's activation time per rail pressure step. P02CF means the learned correction for cylinder 2 has reached its upper limit at at least one pressure step: the injector needs much more activation time than nominal – it delivers too little or opens late, for example from coking. GM diesels set it at limits of roughly ±66–182 µs after two trips. Older GM calibrations (LML) use only this code of the pair, for both directions. It is documented on GM's 6.6 litre L5P and 2.8 litre diesels – on the 2.8 a worn drive belt caused it to return after injector replacement – and on Land Rover's 5.0 V8 petrol, where a software update is the first step. It differs from P01CD (over retarded), which some systems derive from the same learning.
- What you may notice
- Check engine light on
- Often nothing noticeable; possibly rough idle or knocking
- Possibly smoke or loss of power
- Likely causes
- LikelyInjector of cylinder 2 coked or worn (delivers too little)
- PossibleEngine software (update available for some models)
- PossibleInjector correction code not or wrongly programmed after replacement
- RareDisturbed crankshaft signal (worn drive belt, tone wheel, dual-mass flywheel)
- RareLow compression on this cylinder
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €0 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.