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Home >> Acura >> 2003 >> MDX Base >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306: Random Misfire and Any Combination of the Following; No. 1 Cylinder Misfire Detected; No. 2 Cylinder Misfire Detected; No. 3 Cylinder Misfire Detected; No. 4 Cylinder Misfire Detected; No. 5 Cylinder Misfire Detected; No. 6 Cylinder Misfire Detected

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306: Random Misfire and Any Combination of the Following; No. 1 Cylinder Misfire Detected; No. 2 Cylinder Misfire Detected; No. 3 Cylinder Misfire Detected; No. 4 Cylinder Misfire Detected; No. 5 Cylinder Misfire Detected; No. 6 Cylinder Misfire Detected

Special Tools Required 

NOTE:
  • Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  • If the misfire is frequent enough to trigger detection of increased emissions during 2 consecutive driving cycles, the MIL will come on, and DTC P0300 (and some combination of P0301 through P0306) will be stored.
  • If the misfire is frequent enough to damage the catalyst, the MIL will blink whenever the misfire occurs, and DTC P0300 (and some combination of P0301 through P0306) will be stored. When the misfire stops, the MIL will remain on.
  • Troubleshoot the following DTCs first if any of them were stored along with the random misfire DTC(s):

P0107, P0108, P1128, P1129: Manifold absolute pressure (MAP) sensor

P0171, P0172: Fuel system

P0335, P0339, P0385, P0389: Crankshaft position (CKP) sensor A/B

P0506, P0507: Idle control system

P0340, P0344: Camshaft position (CMP) sensor

P0401, P0404, P0406, P2413: Exhaust gas recirculation (EGR) system

  1. Clear the DTC with the HDS.
  2. Start the engine, and let it idle without load (in Park or neutral).
  3. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS.

    Does the screen indicate FAILED? 

    1. YES  - Go to step  8.
    2. NO  - If the screen indicates PASSED, go to step 4. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, wait for several minutes, and recheck.
  4. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

    Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? 

    1. YES  - Go to step  8.
    2. NO  - Go to step 5.
  5. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • Engine speed
    • Vehicle speed
    • Throttle position
    • CLV (calculated load value)
    • Gear position
    • Engine coolant temperature
  6. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS.

    Does the screen indicate FAILED? 

    1. YES  - Go to step  8.
    2. NO  - If the screen indicates PASSED, go to step 7. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step  5 and recheck.
  7. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

    Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? 

    1. YES  - Go to step 8.
    2. NO  - Intermittent failure, system is OK at this time.
  8. Turn the ignition switch OFF.
  9. Check fuel quality.

    Is the quality good? 

    1. YES  - Go to step 10.
    2. NO  - Drain the tank and fill it with a known-good fuel, then go to step  19.
  10. Clean all the spark plugs.
  11. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • Engine speed
    • Vehicle speed
    • Throttle position
    • CLV (calculated load value)
    • Gear position
    • Engine coolant temperature
  12. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

    Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? 

    1. YES  - Go to step 13.
    2. NO  - Go to step  19.
  13. Check the fuel pressure (see FUEL PRESSURE TEST ).

    Is the fuel pressure OK? 

    1. YES  - Go to step 14.
    2. NO  -
  14. Turn the ignition switch OFF.
  15. Remove the rocker arm oil pressure switch (VTEC oil pressure switch) (A), and install the special tools as shown in Fig 1, then install the rocker arm oil pressure switch (VTEC oil pressure switch) (A) in the pressure gauge adapter (B).
    NOTE: Install the part in the reverse order of removal with a new O-ring.
    Fig 1: Removing Rocker Arm Oil Pressure (VTEC Oil Pressure Switch) And Installing Special Tools
    G03639732Courtesy of AMERICAN HONDA MOTOR CO., INC.
  16. Reconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.
  17. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on.
  18. Check the oil pressure at engine speeds of 1,000 and 2,000 rpm. Keep the measuring time as short as possible (less than 1 minute) because the engine is running without load.

    Is the oil pressure below 49 kPa (0.5 kgf/cm 2  , 7 psi)? 

    1. YES  - Check for air in the fuel line (see FUEL LINE INSPECTION ), then go to step 19.
    2. NO  - Inspect the rocker arm oil control solenoid (VTEC solenoid valve), then go to step 19.
  19. Turn the ignition switch ON (II).
  20. Reset the PCM with the HDS.
  21. Clear the CKP PATTERN with the HDS.
  22. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  23. Do the CKP pattern learn procedure (see CKP PATTERN CLEAR/CKP PATTERN LEARN ).
  24. Test-drive the vehicle for several minutes in the range of the recorded freeze data.
  25. Check for Temporary DTCs or DTCs with the HDS.

    Are any Temporary DTCs or DTCs indicated? 

    1. YES  - If DTC P0301, P0302, P0303, P0304, P0305, or P0306 are indicated, check for poor connections or loose terminals at the ignition coil, the injector, and the PCM, then go to troubleshooting DTC P0301, P0302, P0303, P0304, P0305, or P0306 (see DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected; DTC P0305: No. 5 Cylinder Misfire Detected; DTC P0306: No. 6 Cylinder Misfire Detected  ). If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
    2. NO  - Go to step 26.
  26. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS.

    Does the screen indicate PASSED? 

    1. YES  - Troubleshooting is complete.
    2. NO  - If the screen indicates FAILED, go to step  1 and recheck. If the screen indicates EXECUTING, keep the driving condition continually until a result comes on. If the screen indicates OUT OF CONDITION, go to step  24 and recheck.
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