What Does P02F1 Mean?
The ECM has detected that the Cylinder 4 fuel injector circuit is operating outside the expected electrical range or performance parameters. The injector driver current, voltage, or response characteristics deviate from calibrated values, indicating the Cylinder 4 injector or its circuit has degraded beyond acceptable tolerances.
Common Causes
35%
Degraded Cylinder 4 fuel injector with altered coil impedance or mechanical response affecting circuit performance
25%
High-resistance wiring or connector issues in the Cylinder 4 injector circuit
20%
ECM injector driver circuit fault affecting Cylinder 4 output current waveform
20%
Incorrect injector specification installed in Cylinder 4 position
Diagnostic Steps
1
Step 1: Measure Cylinder 4 injector coil resistance and compare to specification and to the other cylinder injectors. Deviation beyond 10% indicates injector degradation.
2
Step 2: Capture the Cylinder 4 injector current waveform using an oscilloscope and current clamp. Analyze for correct peak current, hold current, and switching transient timing.
3
Step 3: Inspect Cylinder 4 injector connector and wiring for corrosion, heat damage, or mechanical damage. Verify terminal tension and proper connector locking.
4
Step 4: Swap the Cylinder 4 injector with a known-good cylinder, clear codes, and monitor. The fault following the injector confirms a component-level failure.
5
Step 5: Verify the correct injector part number and any required injector coding or calibration values are programmed in the ECM for Cylinder 4.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
The ECM has detected that the Cylinder 4 fuel injector circuit is operating outside the expected electrical range or performance parameters. The injector driver current, voltage, or response characteristics deviate from calibrated values, indicating the Cylinder 4 injector or its circuit has degrade...
The most common cause of P02F1 (Cylinder 4 Injector Circuit Range/Performance) is: Degraded Cylinder 4 fuel injector with altered coil impedance or mechanical response affecting circuit performance
Typical repair costs for P02F1 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Cylinder 4 injector circuit performance deviations cause imprecise fueling, potential misfire, elevated emissions, and risk of catalytic converter damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P02F1 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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