P2E5E — Cylinder 6 Alternative Fuel Misfire Detected

Diagnostic algorithm

1. Retrieve DTCs and freeze-frame data; confirm vehicle operating on alternative fuel during code occurrence.
2. Clear codes and road test to reproduce; record misfire counters and fuel system data with a scan tool.
3. Inspect spark plug and coil for cylinder 6; replace or swap with a known-good unit to see if code follows.
4. Inspect and test the alternative-fuel injector/valve for cylinder 6: check electrical continuity, resistance, and operation (use a scope or noid light where appropriate).
5. Check alternative-fuel supply: verify regulator/vaporizer output, fuel rail pressure, filters and solenoids. Confirm fuel composition sensor (E85 sensor) if equipped is reading correctly.
6. Perform a compression test and/or cylinder leak-down test on cylinder 6 and compare to adjacent cylinders; repair mechanical issues if found.
7. Use an oscilloscope or secondary ignition tester to verify healthy ignition secondary waveform and correct spark energy on cylinder 6.
8. Check for intake manifold leaks or vacuum leaks near cylinder 6, and inspect wiring harness and connectors for corrosion or damage.
9. Swap the injector and/or coil between cylinder 6 and another cylinder (if allowed by manufacturer) and retest to determine if fault follows component.
10. If tests point to sensors, verify crank/cam sensor signals and update PCM software or apply manufacturer technical service bulletins if available.
11. After repairs, clear codes and perform a prolonged drive cycle on the alternative fuel to verify the misfire monitor completes and the code does not return.