Worn, clogged or sticking cylinder 10 fuel injector delivering more or less fuel than commanded; Wiring or connector fault on the cylinder 10 injector circuit, such as high resistance or corrosion; Injector leaking or dripping fuel into the cylinder; Fuel pressure problem, such as a weak pump, restricted filter or faulty regulator, affecting delivery; Air leak or mechanical fault on cylinder 10, such as low compression or intake leak, causing the ECU to over-trim fuel; Outdated or faulty ECU calibration affecting injector learning; Internal fault in the ECU injector driver.

P02DF

Cylinder 10 Fuel Injector A Offset Learning 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)
DF: FaultThe specific fault in that area

What it means

P02DF means the engine control unit has found that the learned offset for the cylinder 10 fuel injector (circuit or bank A) has reached its maximum adjustment limit. The ECU trims each injector to correct for small differences in flow or response, and it can no longer compensate for cylinder 10 within its permitted range. This code only applies to engines with ten or more cylinders, and the exact injector learning method varies by manufacturer and engine.

Symptoms

Engine management warning light on
Rough idle or misfire felt mainly at low speed
Hesitation or reduced power under load
Poor fuel economy
Occasional hard starting or uneven running when cold
Possible smell of unburnt fuel

Possible causes

Worn, clogged or sticking cylinder 10 fuel injector delivering more or less fuel than commandedlikely
Wiring or connector fault on the cylinder 10 injector circuit, such as high resistance or corrosionpossible
Injector leaking or dripping fuel into the cylinderpossible
Fuel pressure problem, such as a weak pump, restricted filter or faulty regulator, affecting deliverypossible
Air leak or mechanical fault on cylinder 10, such as low compression or intake leak, causing the ECU to over-trim fuelpossible
Outdated or faulty ECU calibration affecting injector learningrare
Internal fault in the ECU injector driverrare

How to diagnose

Read all stored and pending codes and note any misfire, fuel trim or injector circuit codes alongside P02DF
Review freeze frame data and live fuel trims to see whether the correction is on one cylinder or across the bank
Inspect the cylinder 10 injector connector and wiring for damage, corrosion, chafing and poor pin tension
Measure the injector circuit resistance and supply voltage against the manufacturer's specification
Check fuel pressure and volume against specification, and look for fuel filter restrictions where fitted
Check for intake air leaks and inspect vacuum hoses and manifold seals near cylinder 10
Compare injector balance or cylinder contribution figures with other cylinders, using the method suited to the engine
Carry out a compression or leak-down test on cylinder 10 if the fuel system checks out fine

How to fix

Repair or replace damaged wiring or connectors on the cylinder 10 injector circuit
Clean or replace the faulty cylinder 10 injector, then perform the injector learning or adaptation reset as the manufacturer specifies
Correct fuel pressure faults by replacing the failing pump, filter or regulator as diagnosed
Repair any intake air leaks found
Repair the mechanical fault on cylinder 10 if compression or sealing is poor
Update the ECU calibration only if the manufacturer lists an outdated or faulty calibration as a known cause

Can I keep driving?

Medium severity

Short, gentle journeys are usually possible, but get it checked soon. A faulty injector can cause misfires, wash oil from the bores and damage the catalytic converter, so avoid heavy loads and stop driving if the engine runs roughly or the warning light flashes.

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