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Home >> Acura >> 2004 >> MDX Base >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P0301, P0302, P0303, P0304, P0305, P0306: 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 P0301, P0302, P0303, P0304, P0305, P0306: 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

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  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. Remove the intake manifold cover (see step 1 in REMOVAL ).
  10. Start the engine, and listen for a clicking sound at the injector of the problem cylinder.

    Does the injector click? 

    1. YES  - Go to step 11.
    2. NO  - Go to step  21.
  11. Turn the ignition switch OFF.
  12. Exchange the ignition coil from the problem cylinder with one from another cylinder.
  13. 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
  14. 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 15.
    2. NO  - Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time). Make sure the coil connections are secure.
  15. Determine which cylinder had the misfire.

    Does the misfire occur in the cylinder where the ignition coil was moved? 

    1. YES  - Replace the faulty ignition coil (seeIGNITION COIL REMOVAL/INSTALLATION ), then go to step  42.
    2. NO  - Go to step 16.
  16. Turn the ignition switch OFF.
  17. Exchange the spark plug from the problem cylinder with one from another cylinder.
  18. 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
  19. 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 20.
    2. NO  - Intermittent misfire due to spark plug fouling (no misfire at this time).
  20. Determine which cylinder had the misfire.

    Does the misfire occur in the cylinder where the spark plug was moved? 

    1. YES  - Replace the faulty spark plug, then go to step  42.
    2. NO  - Go to step 21.
  21. Turn the ignition switch OFF.
  22. Exchange the injector from the problem cylinder with one from the another cylinder.
  23. Start the engine, and let it idle for 2 minutes.
  24. 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
  25. 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 26.
    2. NO  - Intermittent misfire due to bad contact in the injector connector (no misfire at this time). Check for poor connections or loose terminals at the injector.
  26. Determine which cylinder had the misfire.

    Does the misfire occur in the cylinder where the injector was exchanged? 

    1. YES  - Replace the faulty injector (see INJECTOR REPLACEMENT  ), then go to step  42.
    2. NO  - Go to step 27.
  27. Turn the ignition switch OFF.
  28. Disconnect the ignition coil 3P connector from the problem cylinder.
  29. Turn the ignition switch ON (II).
  30. Measure voltage between ignition coil 3P connector terminal No. 3 and body ground.
    Fig 1: Measuring Voltage Between Ignition Coil 3P Connector Terminal 3 And Body Ground
    G03639733Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  - Go to step 31.
    2. NO  - Repair open in the wire between the ignition coil and the ignition coil relay, then go to step  42.
  31. Turn the ignition switch OFF.
  32. Check for continuity between ignition coil 3P connector terminal No. 2 and body ground.
    Fig 2: Checking Continuity Between Ignition Coil 3P Connector Terminal 2 And Body Ground
    G03639734Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step 33.
    2. NO  - Repair open in the wire between the ignition coil and G101 and G102, then go to step  42.
  33. Turn the ignition switch OFF.
  34. Jump the SCS line with the HDS.
  35. Disconnect PCM connector A (73P).
  36. Check for continuity between body ground and the appropriate PCM connector terminal (see Fig 3 ).
    Fig 3: Checking Continuity Between Body Ground And Appropriate PCM Connector Terminal Chart
    G03639735Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair short in the wire between the PCM and the ignition coil, then go to step  42.
    2. NO  - Go to step 37.
  37. Connect appropriate ignition coil 3P connector terminal No. 1 to body ground with a jumper wire (see Fig 4 ).
    Fig 4: Connecting Ignition Coil 3P Connector Terminal 1 To Body Ground With Jumper Wire Chart
    G03639736Courtesy of AMERICAN HONDA MOTOR CO., INC.
  38. Check for continuity between body ground and the appropriate PCM connector terminal (see Fig 5 ).
    Fig 5: Checking Continuity Between Body Ground And PCM Connector Terminal Chart
    G03639737Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step 39.
    2. NO  - Repair open in the wire between the PCM and the ignition coil, then go to step  42.
  39. Reconnect the ignition coil 3P connector and PCM connector A (73P).
  40. Do an engine compression and a cylinder leakdown test.

    Did the engine pass both tests? 

    1. YES  - Go to step 41.
    2. NO  - Repair the engine, then go to step  42.
  41. Do the VTEC rocker arm test (see VTEC ROCKER ARM TEST ).

    Did the engine pass test? 

    1. YES  - Go to step  50.
    2. NO  - Repair the VTEC rocker arm (see VTEC ROCKER ARM TEST ), then go to step 42.
  42. Turn the ignition switch ON (II).
  43. Reset the PCM with the HDS.
  44. Clear the CKP PATTERN with the HDS.
  45. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  46. Do the CKP pattern learn procedure (see CKP PATTERN CLEAR/CKP PATTERN LEARN ).
  47. 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
  48. 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 P0300: Random Misfire and Any Combination of the Following:; 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 49.
  49. 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  47 and recheck.
  50. Update the PCM if it does not have the latest software, or substitute a known-good PCM (see PCM UPDATING AND SUBSTITUTION FOR TESTING ).
  51. 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
  52. 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 injector, the ignition coil, and the PCM, then go to step  1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
    2. NO  - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT  ).
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