DTC P0301-DTC P0304: Cylinder Misfire Detected: Notes

Turn ignition off. Disconnect PCM connector. Connect scan tool. Retrieve DTC(s). If no other DTCs exist, go to next step. If DTC(s) P0101, P0102, P0103, P0116, P0117, P0125, P0261, P0262, P0264, P0265, P0267, P0268, P0270, or P0271 exist, diagnose affected DTC(s). DO NOT diagnose misfire DTC.
Clear PCM memory using scan tool. Start engine and drive vehicle for more than 10 minutes. If MIL illuminates or flashes, go to step 4). If MIL does not illuminate, go to next step.
Determine if vehicle has run out of fuel in the recent past. If vehicle has run out of fuel, engine has no abnormality. Finish diagnostics operation. If vehicle has not been run out of fuel, check for abnormalities in ignition system including the following:
- Open Circuit Between PCM & Injectors
- Ignition Coil Connector
- Ignitor Connector
- Injector Connector
- PCM Connector
Repair as necessary. If ignition system is okay, finish diagnostics operation.
Inspect air intake system for air leaks or air suction caused by loose or missing nuts or bolts. Check for cracks or loose connections of any hoses in system and repair as necessary. If no leaks are found, go to next step.

Perform diagnosis according to items in SYMPTOM CHECK table.

SYMPTOM CHECK

If engine idle is rough, observe minimum EGR pressure display on scan tool. If EGR pressure is less than one kPa, clean EGR valve. Ensure valve operates smoothly and valve seat area is completely clean. Replace EGR valve if required. If EGR pressure value is more than one kPa, diagnose using DTC P0170 and retest.