[13C] MULTIPORT FUEL INJECTION (MPI) <4G69> - - TROUBLESHOOTING - INSPECTION PROCEDURE FOR DIAGNOSIS CODES - Code No. P0304: No. 4 Cylinder Misfire Detected | PRINT PAGE / INDEX / PRIOR / NEXT

Code No. P0304: No. 4 Cylinder Misfire Detected
OPERATION Refer to Code No. P0204 No. 4 Injector System .
FUNCTION If a misfire occurs while the engine is running, the engine speed changes for an instant. The engine-A/T-ECU checks for such changes in engine speed.
TROUBLE JUDGMENT Check Conditions Engine speed is 500 - 6,500 r/min. Engine coolant temperature is -10°C or higher. Barometric pressure is 76 kPa or higher. Volumetric efficiency is between 30% and 55%. Adaptive learning is complete for the vane which generates a crankshaft position signal. While the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching. The throttle deviation is -0.06 V/10 ms to +0.06 V/10 ms. Judgment Criteria (change in the angular acceleration of the crankshaft is used for misfire detection). Misfire has occurred more frequently than the limit during the last 200 revolutions (when the catalyst temperature has been 950°C or higher). or Misfire has occurred 15 times or more in the last 1,000 revolutions (that has been equivalent to approximately 1.5 times the emission standard).
PROBABLE CAUSE Ignition system related part(s) failed Low compression pressure Failed engine-A/T-ECU
| DIAGNOSIS PROCEDURE
| STEP 1. Check the ignition coil spark. Q: Is the check result normal? YES: Go to Step 2 . NO: Check ignition Circuit System (Refer to Inspection Procedure 31 ).
| STEP 2. Connector check: B-05 No. 4 injector connector
| Q: Is the check result normal? YES: Go to Step 3 . NO: Repair.
| STEP 3. Check No. 4 injector itself. Check Injector itself (Refer to ). Q: Is the check result normal? YES: Go to Step 4 . NO: Replace No. 4 injector.
| STEP 4. Connector check: B-17X engine control relay connector and C-134 engine-A/T-ECU connector
| Q: Is the check result normal? YES: Go to Step 5 . NO: Repair.
| STEP 5. Check harness between B-17X (terminal No. 1) engine control relay connector and B-05 (terminal No. 1) No. 4 injector connector.
| Check power supply line for damage. Q: Is the check result normal? YES: Go to Step 6 . NO: Repair.
| STEP 6. Check harness between B-05 (terminal No. 2) No. 4 injector connector and C-134 (terminal No. 21) engine-A/T-ECU connector.
| Check output line for damage. Q: Is the check result normal? YES: Go to Step 7 . NO: Repair.
| STEP 7. Fuel pressure measurement. Fuel pressure measurement (Refer to Fuel Pressure Test ) Q: Is the check result normal? YES: Go to Step 8 . NO: Repair.
| STEP 8. Check the trouble symptoms. Q: Does trouble symptom persist? YES: Replace engine-A/T-ECU. NO: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points).

[13C] MULTIPORT FUEL INJECTION (MPI) <4G69> - - TROUBLESHOOTING - INSPECTION PROCEDURE FOR DIAGNOSIS CODES - Code No. P0304: No. 4 Cylinder Misfire Detected | PRINT PAGE / INDEX / PRIOR / NEXT

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