Clogged, restricted, or leaking cylinder 1 fuel injector; Carbon buildup on the cylinder 1 intake valve or port causing uneven airflow; Failed or contaminated engine oil leading to a sticking injector pintle; Wiring harness damage or poor electrical connection at the cylinder 1 injector; Low fuel pressure or a restricted fuel filter affecting all injectors but most noticeable on cylinder 1; Worn spark plug or ignition coil on cylinder 1 creating a false fuel trim correction; Engine control module software calibration issue requiring a reflash

DTC codes / P02xx · Fuel and air metering (injector circuits) / P02CC

P02CCCylinder 1 Fuel Injector A Offset Learning At Min Limit

Q: What does code P02CC mean?

Cylinder 1 Fuel Injector A Offset Learning At Min Limit. P02CC indicates that the engine control module has learned a fuel injector offset correction for cylinder 1 that has reached its minimum allowable limit. The computer commands a specific fuel delivery and monitors the resulting crankshaft speed or air-fuel ratio feedback, and the learned correction needed to keep cylinder 1 balanced has hit the bottom of its adjustment window.

P02CC indicates that the engine control module has learned a fuel injector offset correction for cylinder 1 that has reached its minimum allowable limit. The computer commands a specific fuel delivery and monitors the resulting crankshaft speed or air-fuel ratio feedback, and the learned correction needed to keep cylinder 1 balanced has hit the bottom of its adjustment window.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or a slight shake that is more pronounced when the engine is cold
Intermittent misfire sensation or hesitation during light acceleration
Slightly elevated fuel consumption as the engine compensates for the imbalance
A faint fuel odor from the exhaust if the injector is delivering too much fuel

Common causes, most likely first

Clogged, restricted, or leaking cylinder 1 fuel injector
Carbon buildup on the cylinder 1 intake valve or port causing uneven airflow
Failed or contaminated engine oil leading to a sticking injector pintle
Wiring harness damage or poor electrical connection at the cylinder 1 injector
Low fuel pressure or a restricted fuel filter affecting all injectors but most noticeable on cylinder 1
Worn spark plug or ignition coil on cylinder 1 creating a false fuel trim correction
Engine control module software calibration issue requiring a reflash

How to diagnose and fix it

Connect a scan tool and record all freeze-frame data and fuel trim values for cylinder 1
Perform a visual inspection of the cylinder 1 injector connector and wiring for chafing or corrosion
Check fuel pressure and volume against the manufacturer's specification
Run a cylinder contribution or power balance test to confirm the injector is the weak cylinder
Remove and inspect the cylinder 1 spark plug for fouling or incorrect gap
Swap the cylinder 1 injector with another cylinder and see if the offset limit code follows the injector
Replace the faulty injector and clear the adaptive learning, then road-test to verify the correction returns to the normal range

Why cylinder 1 offset codes mislead

A min-limit offset does not always mean the injector is bad; a vacuum leak or exhaust restriction can skew the learned correction on one cylinder.
Technicians often replace the injector without checking the intake valve for carbon, which can mimic a rich injector by restricting airflow.
The adaptive offset can hit its limit from a dirty mass airflow sensor that biases the entire fuel trim before individual cylinder learning occurs.
After injector replacement, the engine control module must relearn the offset; clearing codes alone without a drive cycle may leave the code pending.
A weak ignition coil on cylinder 1 can cause unburned fuel that the oxygen sensor reads as rich, driving the offset to its minimum limit.

Can I keep driving with P02CC?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration and prolonged idling because a rich cylinder can wash oil from the cylinder wall and overheat the catalytic converter. If the check engine light begins flashing, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.