DTC P0301 (CYL1), DTC P0302 (CYL2), DTC P0303 (CYL3), DTC P0304 (CYL4): Cylinder Misfire Detected
- Turn ignition off. Disconnect ECM connector. Connect SSM. Retrieve DTC(s). If DTC 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. If no other DTCs exist, go to next step.
- Turn ignition off. Set SSM to function mode F42 to read minimum EGR system pressure value and note for future use. Turn ignition on. Record any displayed values. Clear ECM memory using SSM. 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 empty of fuel, check for abnormalities in ignition system. 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, or cracks or loose connection of any hoses in system and repair as necessary. If no leaks are found, go to next step.
- Turn ignition off. Set SSM to function mode FB1. Perform diagnosis according to items in the SYMPTOM CHECK table.SYMPTOM CHECK
DTC Go To Step Only One Misfiring Cylinder "a" P0301 & P0302 "b" P0303 & P0304 "c" P0301 & P0303 "d" P0302 & P0304 "e" Random Misfire "f" "a" - Only One Cylinder. Check following items for that cylinder:
- Spark plug
- Spark plug wire
- Fuel injector
- Compression
Repair or replace as needed. If no problems are found, go to step 6).
"b" - Group Of Cylinders No. 1 & 2. Check following items for cylinders No. 1 and 2:
- Spark plugs
- Fuel injectors
- Igniters, ignition coils, etc.
Repair or replace as needed. If no problems are found, go to step 6).
"c" - Group Of Cylinders No. 3 & 4. Check following items for cylinders No. 3 and 4:
- Spark plugs
- Fuel injectors
- Igniters, ignition coils, etc.
Repair or replace as needed. If no problems are found, go to step 6).
"d" - Group Of Cylinders No. 1 & 3. Check following items for cylinders No. 1 and 3:
- Spark plugs
- Fuel injectors
- Skipped/jumped timing belt
Repair or replace as needed. If no problems are found, go to step 6).
"e" - Group Of Cylinders No. 2 & 4. Check following items for cylinders No. 2 and 4:
- Spark plugs
- Fuel injectors
- Skipped/jumper timing belt teeth
Repair or replace as needed. If no problems are found, go to step 6).
"f" - Cylinder At Random
- If engine idle is not rough, go to DTC P0170 and retest.
- If engine idle is rough, refer to minimum EGR pressure (function mode F42) noted in step 2). 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.CAUTION: DO NOT use solvent when cleaning EGR valve assembly, as it can damage diaphragm.