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Home >> Honda >> 2011 >> CR-Z Base, Automatic CVT >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Testing and Diagnosis >> IMA System >> DTC Troubleshooting >> DTC U0038: IMA-CAN Malfunction (BUS-OFF (Motor Control Module (MCM))); DTC U1204: IMA-CAN Malfunction (Powertrain Control Module (PCM) - Motor Control Module (MCM))
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DTC U0038: IMA-CAN Malfunction (BUS-OFF (Motor Control Module (MCM))); DTC U1204: IMA-CAN Malfunction (Powertrain Control Module (PCM) - Motor Control Module (MCM))

NOTE: Before you troubleshoot, record all freeze data, and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION  ).
  1. Turn the ignition switch to ON (II).
  2. Check for ENGINE COOLANT TEMPERATURE in the IMA DATA LIST with the HDS.

    Is 419°F (215°C) indicated? 

    YES  -Go to step  3.

    NO  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ECM/PCM and the MCM.

  3. Jump the SCS line with the HDS.
  4. Turn the ignition switch to LOCK (0).
  5. Disconnect ECM/PCM connector A (44P).
  6. Measure the resistance between ECM/PCM connector terminals A38 and A39.
    Fig 1: Measuring Resistance Between ECM/PCM Connector Terminals A38 And A39
    G06950479Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 120 Ω? 

    YES  -Go to step  21.

    NO  -Go to step  7.

  7. Measure the resistance between ECM/PCM connector terminals A38 and A39.
    Fig 2: Measuring Resistance Between ECM/PCM Connector Terminals A38 And A39
    G06950480Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 0 Ω? 

    YES  -Go to step  8.

    NO  -Go to step  14.

  8. Turn the ignition switch to LOCK (0).
  9. Turn the battery module switch OFF (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT  ).
  10. Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ).
  11. Remove the PCU lid, the PCU busplate, and the PCU cover (see IPU CASE REMOVAL/INSTALLATION  ).
  12. Disconnect MCM connector A (31P).
  13. Check for continuity between MCM connector terminals A1 and A2.
    Fig 3: Checking Continuity Between MCM Connector Terminals A1 And A2
    G06950481Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short in the wire between MCM connector terminals A1 and A2, then go to step  35.

    NO  -Go to step  41.

  14. Turn the ignition switch to LOCK (0).
  15. Turn the battery module switch OFF (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT  ).
  16. Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ).
  17. Remove the PCU lid, the PCU busplate, and the PCU cover (see IPU CASE REMOVAL/INSTALLATION  ).
  18. Disconnect MCM connector A (31P).
  19. Check for continuity between MCM connector terminal A2 and ECM/PCM connector terminal A38.
    Fig 4: Checking Continuity Between MCM Connector Terminal A2 And ECM/PCM Connector Terminal A38
    G06950482Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step  20.

    NO  -Repair an open in the wire between the ECM/PCM (A38) and the MCM (A2), then go to step  35.

  20. Check for continuity between MCM connector terminal A1 and ECM/PCM connector terminal A39.
    Fig 5: Checking Continuity Between MCM Connector Terminal A1 And ECM/PCM Connector Terminal A39
    G06950483Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step  41.

    NO  -Repair an open in the wire between the ECM/PCM (A39) and the MCM (A1), then go to step  35.

  21. Turn the ignition switch to LOCK (0).
  22. Turn the battery module switch OFF (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT  ).
  23. Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ).
  24. Remove the PCU lid, the PCU busplate, and the PCU cover (see IPU CASE REMOVAL/INSTALLATION  ).
  25. Disconnect MCM connector A (31P).
  26. Turn the ignition switch to ON (II).
  27. Check for continuity between MCM connector terminal A2 and body ground.
    Fig 6: Checking Continuity Between MCM Connector Terminal A2 And Body Ground
    G06950484Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire between the ECM/PCM (A38) and the MCM (A2), then go to step  35.

    NO  -Go to step  28.

  28. Check for continuity between MCM connector terminal A1 and body ground.
    Fig 7: Checking Continuity Between MCM Connector Terminal A1 And Body Ground
    G06950485Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire between the ECM/PCM (A39) and the MCM (A1), then go to step  35.

    NO  -Go to step  29.

  29. Turn the ignition switch to ON (II).
  30. Measure the voltage between MCM connector terminal A2 and body ground.
    Fig 8: Measuring Voltage Between MCM Connector Terminal A2 And Body Ground
    G06950486Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5-12 V? 

    YES  -Repair a short to power in the wire between the ECM/PCM (A38) and the MCM (A2), then go to step  35.

    NO  -Go to step  31.

  31. Measure the voltage between MCM connector terminal A1 and body ground.
    Fig 9: Measuring Voltage Between MCM Connector Terminal A1 And Body Ground
    G06950487Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5-12 V? 

    YES  -Repair a short to power in the wire between the ECM/PCM (A39) and the MCM (A1), then go to step  35.

    NO  -Go to step  32.

  32. Turn the ignition switch to LOCK (0).
  33. Reconnect ECM/PCM connector A (44P).
  34. Measure the resistance between MCM connector terminals A1 and A2.
    Fig 10: Measuring Resistance Between MCM Connector Terminals A1 And A2
    G06950488Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 120 Ω? 

    YES  -Go to step  41.

    NO  -Update the ECM/PCM if it does not have the latest software (see ELD REPLACEMENT ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ), then go to step  35.

  35. Reconnect all connectors.
  36. Reinstall the PCU cover, the PCU busplate, and the PCU lid (see IPU CASE REMOVAL/INSTALLATION  ).
  37. Reinstall the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ), then turn the battery module switch ON (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT  ).
  38. Turn the ignition switch to ON (II).
  39. Clear the DTC with the HDS (see DTC CLEAR  ).
  40. Check for Pending or Confirmed DTCs in the IMA SYSTEM with the HDS.

    Is DTC U0038 or U1204 indicated? 

    YES  -Check for poor connections or loose terminals at the ECM/PCM and the MCM, then go to step  1.

    NO  -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC'S TROUBLESHOOTING .

  41. Reconnect all connectors.
  42. Reinstall the PCU cover, the PCU busplate, and the PCU lid (see IPU CASE REMOVAL/INSTALLATION  ).
  43. Reinstall the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ), then turn the battery module switch ON (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT  ).
  44. Update the MCM if it does not have the latest software (see MOTOR CONTROL MODULE (MCM) UPDATE  ), or substitute a known-good MCM (see SUBSTITUTING THE MCM  ).
  45. Turn the ignition switch to ON (II).
  46. Check for Pending or Confirmed DTCs with the HDS in the IMA SYSTEM.

    Is DTC U0038 or U1204 indicated? 

    YES  -Check for poor connections or loose terminals at the ECM/PCM and the MCM. If the MCM was updated, substitute a known-good MCM (see SUBSTITUTING THE MCM  ), then recheck. If the MCM was substituted, go to step  1.

    NO  -If the MCM was updated, troubleshooting is complete. If the MCM was substituted, replace the original MCM (see IPU CASE REMOVAL/INSTALLATION  ). If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC'S TROUBLESHOOTING .