Wiring fault in the cylinder 3 injector circuit, such as chafing, high resistance, or a short to earth or supply; Corroded, loose or damaged injector connector or terminals at cylinder 3; Cylinder 3 injector with faulty internal winding or mechanical sticking, giving out-of-range electrical behaviour; Poor earth or low supply voltage affecting the injector circuit, for example from a weak battery or charging fault; Fault in the engine control unit injector driver stage; Outdated or faulty control unit software where a manufacturer bulletin lists it as a known cause.

P02F0

Cylinder 3 Injector Circuit Range/Performance.

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)
F0: FaultThe specific fault in that area

What it means

P02F0 is a generic powertrain code meaning the engine control unit has found the cylinder 3 fuel injector circuit operating outside its expected range or performance. The control unit monitors the injector driver, its current or voltage behaviour and the response of the circuit, and it set this code because the readings did not match what it expected. The exact monitoring method and set conditions vary by manufacturer and engine, so check the vehicle-specific information.

Symptoms

Engine misfire or rough running, mainly on cylinder 3
Rough idle or hesitation under load
Reduced power or the car going into limp mode
Poor fuel economy or a fuel smell
Malfunction indicator lamp on, possibly flashing during a misfire
Hard starting or occasional stalling

Possible causes

Wiring fault in the cylinder 3 injector circuit, such as chafing, high resistance, or a short to earth or supplylikely
Corroded, loose or damaged injector connector or terminals at cylinder 3likely
Cylinder 3 injector with faulty internal winding or mechanical sticking, giving out-of-range electrical behaviourlikely
Poor earth or low supply voltage affecting the injector circuit, for example from a weak battery or charging faultpossible
Fault in the engine control unit injector driver stagerare
Outdated or faulty control unit software where a manufacturer bulletin lists it as a known causerare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine load, temperature and battery voltage when the fault set, and check for other injector or misfire codes
Check battery condition and charging voltage, as low voltage can upset injector circuit monitoring
Visually inspect the cylinder 3 injector connector, terminals and wiring harness for damage, corrosion, moisture, oil contamination or heat damage
Check the injector coil resistance against the manufacturer's specification, with the connector disconnected and the ignition off
Test the injector circuit wiring for continuity, short to earth and short to supply between the injector and the control unit, following the wiring diagram
With a suitable scope or injector test function, compare the cylinder 3 injector waveform or activation with another cylinder
Swap the cylinder 3 injector with another cylinder, if the engine design allows, and see whether the fault follows it
Check for manufacturer software updates or technical bulletins for this engine, and refer to model-specific procedures for the injector type

How to fix

Repair or replace damaged wiring in the cylinder 3 injector circuit and secure the harness away from heat and abrasion
Clean or replace the corroded or damaged connector and terminals
Replace the cylinder 3 injector if its resistance, waveform or operation is out of specification, following the correct procedure for the engine (some systems need injector coding or adaptation)
Repair the battery, charging system or earth fault causing low or unstable voltage
Replace or repair the control unit only after all wiring and injector checks have been passed and the driver fault is confirmed
Update the control unit software only if a bulletin identifies it as the cause

Can I keep driving?

Medium severity

The car can usually be driven carefully for a short time to reach a workshop, but get it checked soon. Avoid heavy loads, and stop driving if the engine runs very roughly, the warning light flashes or you smell fuel, as a misfire can damage the catalytic converter and a leaking injector can damage the engine.

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