Open or high-resistance wiring in the cold start injector control circuit; Failed cold start fuel injector (open coil or internal short); Corroded, loose, or damaged electrical connector at the injector or PCM; Short to voltage on the control wire between the PCM and the injector; Faulty PCM driver for the cold start injector circuit; Poor engine ground connection affecting the injector return path

DTC codes / P02xx · Fuel and air metering (injector circuits) / P02FD

P02FDCold Start Fuel Injection Control Circuit High

Q: What does code P02FD mean?

Cold Start Fuel Injection Control Circuit High. P02FD indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the cold start fuel injection control circuit, which is used to enrich the fuel mixture during engine warm-up. The PCM monitors the circuit for expected voltage drops when the injector is commanded on, and a sustained high voltage tells the module that the circuit is open, shorted to power, or that the injector driver has failed.

P02FD indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the cold start fuel injection control circuit, which is used to enrich the fuel mixture during engine warm-up. The PCM monitors the circuit for expected voltage drops when the injector is commanded on, and a sustained high voltage tells the module that the circuit is open, shorted to power, or that the injector driver has failed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or stumbling immediately after a cold start
Extended cranking time before the engine fires when cold
Hesitation or flat spot during the first few minutes of driving
Increased fuel consumption during warm-up
In rare cases, a no-start condition when the engine is cold

Common causes, most likely first

Open or high-resistance wiring in the cold start injector control circuit
Failed cold start fuel injector (open coil or internal short)
Corroded, loose, or damaged electrical connector at the injector or PCM
Short to voltage on the control wire between the PCM and the injector
Faulty PCM driver for the cold start injector circuit
Poor engine ground connection affecting the injector return path

How to diagnose and fix it

Connect a scan tool and verify P02FD is current, then check for related codes and freeze-frame data
Inspect the cold start injector connector and wiring for corrosion, chafing, or loose pins
Measure the resistance of the cold start injector with a multimeter and compare to specification
Back-probe the control circuit at the PCM and check for voltage when the injector is commanded on
Perform a voltage drop test on the ground side of the circuit to rule out high resistance
Check for a short to voltage on the control wire by disconnecting both ends and measuring to battery positive
If all wiring and the injector test good, suspect the PCM and perform a driver circuit test before replacement

Cold start circuit checks most techs overlook

A cold start injector that tests good on resistance can still fail intermittently when the engine is cold, so test it at low temperature as well as at operating temperature.
The PCM may set P02FD only during the first cold-start window after a key cycle, so clearing the code and test-driving a warm engine will not reproduce the fault.
Corrosion inside the injector connector often looks clean from the outside but creates enough resistance to trigger a high-voltage code without any visible damage.
A weak battery or poor engine ground can cause the PCM to misread injector circuit voltage during cranking, setting this code even though the injector circuit itself is sound.
This code does not always mean the injector is bad; a short to voltage on the control wire from a rubbed harness near the intake or exhaust is a common hidden cause.

Can I keep driving with P02FD?

You can usually drive the vehicle, but expect rough running and higher fuel use during cold starts, and avoid heavy acceleration until the engine reaches operating temperature. If the engine is hard to start or stalls when cold, have it diagnosed promptly to prevent a no-start situation.

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.