P2E5B — Cylinder 3 Alternative Fuel Misfire Detected

Diagnostic algorithm

1. Safety: Park on level surface, set parking brake, chock wheels, and work on a cool engine. Use PPE when handling fuels.
2. Capture codes and live data: Use a scan tool to record misfire counters, freeze frame, fuel system status, and fuel pressure during the fault.
3. Inspect wiring and connectors: Visually and physically check connectors, pins and harness to cylinder 3 injector and ignition components for corrosion, damage or loose contact.
4. Swap test components: Swap the cylinder 3 injector and/or coil with a known-good cylinder. Re-test for code presence to determine if the fault follows the component.
5. Verify alternative fuel supply: Measure alternative fuel rail/line pressure and regulator operation under idle and load. Check for blockages or leaks specific to cylinder 3 feed or nozzle.
6. Fuel injector/flow check: Test injector electrical operation and perform flow/cleaning or replacement if suspect (use procedures appropriate for the particular alternative fuel system).
7. Ignition and spark verification: If system uses spark, inspect spark plug condition, resistances, and check spark (with appropriate tool) on cylinder 3.
8. Compression/leak-down test: Perform compression or leak-down on cylinder 3 to rule out mechanical issues.
9. Sensor verification: Check crank and cam sensor signals for irregularities that may cause false misfire detection.
10. Clear codes and re-test: After repairs or isolation, clear codes and run the vehicle through a complete drive cycle on the alternative fuel to confirm resolution.
11. Software/calibration: If all hardware checks good, check for ECM/alternative fuel module updates or recall TSBs and consider reprogramming or calibration.