Cold start injector or valve faulty internally (open or shorted coil); Wiring damage causing a short to voltage or open circuit in the control wire; Corroded, loose or damaged connector at the injector or control unit; Supply voltage or relay fault feeding the cold start circuit; Another circuit's wire chafing against the control wire and feeding voltage into it; Fault in the injector driver inside the engine control unit.

P02FD

Cold Start Fuel Injection Control Circuit High.

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)
FD: FaultThe specific fault in that area

What it means

P02FD means the engine control unit has detected a high voltage on the control circuit for the cold start fuel injection system, such as a dedicated cold start injector or valve. The voltage was higher than expected when the unit commanded or monitored the circuit, which usually points to a short to voltage, an open circuit or a fault in the driver. Whether the system exists and how it is wired depends on the model and engine.

Symptoms

Engine cranks for longer than normal or is hard to start when cold
Rough or unstable idle after a cold start
Engine management light on
Hesitation or poor running until the engine warms up
Raised fuel consumption or a smell of fuel on cold starts
Normal starting and running once the engine is warm

Possible causes

Cold start injector or valve faulty internally (open or shorted coil)likely
Wiring damage causing a short to voltage or open circuit in the control wirelikely
Corroded, loose or damaged connector at the injector or control unitlikely
Supply voltage or relay fault feeding the cold start circuitpossible
Another circuit's wire chafing against the control wire and feeding voltage into itpossible
Fault in the injector driver inside the engine control unitrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, especially coolant and intake air temperature and whether the engine was cold
Check for related codes covering injectors, fuel pressure or supply voltage, and deal with those first if present
Visually inspect the cold start injector or valve, its wiring and connectors for damage, corrosion, heat damage, chafing and fuel leaks
Check the connector pins for tightness, moisture and bent or pushed-back terminals
Measure the injector or valve coil resistance and compare it with the manufacturer's specification for that engine
With the key on, check the supply voltage and the control wire voltage at the connector against the wiring diagram, looking for voltage where there should be none
Check the control wire for continuity and for a short to voltage, with the control unit connector disconnected as the procedure allows
Check the control signal during a cold start with a scope or suitable test equipment, and only suspect the control unit once wiring and the injector are proven good

How to fix

Replace the cold start injector or valve if its resistance or operation is out of specification
Repair or replace damaged wiring, and secure it so it cannot chafe again
Clean, repair or replace corroded or damaged connectors and terminals
Repair the supply or relay circuit if the voltage is incorrect
Repair or replace the engine control unit only after all other causes are ruled out, following the manufacturer's procedure

Can I keep driving?

Medium severity

The car can usually be driven, but cold starting and running may be poor, and an unresolved fault could leave it hard to start or stalling. Book it in soon, and avoid long journeys if it is struggling to start or running badly.

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