What does it mean?
When the control module energises the cold start fuel injection circuit, the voltage on that driver output has to collapse toward ground so that current can flow through the solenoid. P02FD is stored when the module commands the circuit on but keeps measuring a high voltage on the line, meaning the expected current never appears. Electrically this points to an open circuit, a high resistance joint, or unwanted battery voltage feeding the control line from somewhere else, rather than to any mechanical fuel system problem. Because the additional cold start fuelling cannot be delivered, cold start quality suffers until the engine warms up and the normal injection strategy takes over.
Symptoms
- Hard starting when the engine is cold, sometimes needing several attempts
- Rough running and stumbling in the first minutes after start-up
- MIL on with the code stored, normally logged during a cold start
- Increased warm-up emissions and a slow-to-clear exhaust haze
- No noticeable problem once the engine reaches operating temperature
- Hunting idle speed until coolant temperature rises on some vehicles
Likely causes
- Open or high resistance in the control wire between the module and the cold start injector
- Corroded, loose or backed-out terminals in the injector or module connector
- Control circuit shorted to battery voltage through chafed insulation or a wiring error
- Open winding in the cold start injector solenoid
- Poor ground for the device or for its driver reference
- Faulty module output stage, evaluated only after the wiring has been proven good
How to fix it
- Check the freeze frame data for coolant temperature and engine state at the moment the code set
- Inspect and clean the connectors at the injector and the module, testing terminal tension with a matching probe
- With the ignition on, measure the voltage at the control pin; battery voltage that will not pull down when commanded confirms the condition
- Perform a voltage drop test along the control wire and verify continuity from the module pin to the device pin
- Measure the solenoid winding resistance and compare it with specification
- Check the ground path and the supply feed, including the fuse and relay that serve the circuit
- Repair the wiring fault or renew the injector, then clear the code and verify with a genuine cold start