P2C5F — Cylinder 7 Fuel Injector B Offset Learning At Max Limit

Diagnostic algorithm

1. Retrieve stored codes and freeze-frame data; record injector offset/adaptive values and misfire counts.
2. Visually inspect wiring and connector for injector 7. Repair any damage or corrosion, then clear codes and retest.
3. With a scan tool, monitor injector offset and fuel trims at idle and under load. Note whether offset is maxed continually or only under conditions.
4. Measure injector electrical resistance and compare to other injectors. If out of range, replace the injector.
5. Perform a fuel pressure and flow test to confirm adequate rail pressure and regulator operation.
6. If electrical values are normal, swap injector 7 with another cylinder’s injector and re-run the test to see if the offset follows the injector (confirms hydraulic/mechanical injector fault).
7. If the code stays on cylinder 7 after swapping, perform compression/leak-down test to check for mechanical issues in that cylinder.
8. Check for intake manifold or vacuum leaks, and test MAF/MAP sensors for correct operation if trims indicate intake metering error.
9. If wiring and mechanical checks pass, inspect PCM grounds and consider re-flashing PCM software or performing adaptive memory reset per manufacturer procedure.
10. After repairs, clear codes, perform a road test and confirm injector offset values return to within normal adaptive range and misfires/trims normalize.