LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2012 >> Insight Base >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Testing and Diagnosis >> IMA System >> DTC Troubleshooting >> DTC P1673: Motor Control Module (MCM) Relay Stays Activated
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

DTC P1673: Motor Control Module (MCM) Relay Stays Activated

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 DTC cannot be cleared, do the troubleshooting for DTC U1204.
  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS (see DTC CLEAR ).
  3. Turn the ignition switch to LOCK (0), and wait at least 40 seconds. Turn the ignition switch to ON (II) again.
  4. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P1673 indicated? 

    YES  -Go to step 5.

    NO  -Intermittent failure, the system is OK at this time.

  5. Turn the ignition switch to LOCK (0).
  6. Turn the battery module switch OFF (see TURNING OFF AND ON POWER TO THE HIGH VOLTAGE CIRCUIT ).
  7. Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION ).
  8. Remove MCM relay 1 (A).
    Fig 1: Identifying MCM Relay 1
    G08092893Courtesy of AMERICAN HONDA MOTOR CO., INC.
  9. Measure the voltage between MCM relay 1 4P connector terminals No. 3 and No. 4.
    Fig 2: Measuring Voltage Between MCM Relay 1 4P Connector Terminals No. 3 And No. 4
    G08092894Courtesy of AMERICAN HONDA MOTOR CO., INC.

    When you turn the ignition switch from ON (II) to LOCK (0), does the voltage change from 10 V or more down to 0 V? 

    YES  -Go to step 10.

    NO  -Go to step  11.

  10. Test MCM relay 1 (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Repair a short to power in the wire between MCM relay 1 and the MCM (A1), then go to step  14.

    NO  -Replace MCM relay 1, then go to step  14.

  11. Remove the PCU lid, the PCU busplate, and the PCU cover (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
  12. Disconnect MCM connector A (31P).
  13. Check for continuity between body ground and MCM connector terminal A7.
    Fig 3: Checking Continuity Between Body Ground And MCM Connector Terminal A7
    G08092895Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire between MCM relay 1 and the MCM (A7), then go to step 14.

    NO  -Go to step  22.

  14. Reconnect all connectors.
  15. If removed, reinstall the PCU cover, the PCU busplate, and the PCU lid (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
  16. If removed, 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 ).
  17. Turn the ignition switch to ON (II).
  18. Clear the DTC with the HDS (see DTC CLEAR ).
  19. Turn the ignition switch to LOCK (0), and wait at least 40 seconds. Turn the ignition switch to ON (II) again.
  20. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P1673 indicated? 

    YES  -Go to step  1.

    NO  -Go to step 21.

  21. Monitor the OBD STATUS for DTC P1673 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step  20, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -If the HDS indicates FAILED, go to step  1. If the HDS indicates NOT COMPLETED, go to step  19.

  22. Reconnect all connectors.
  23. Reinstall the PCU cover, the PCU busplate, and the PCU lid (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
  24. 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 ).
  25. 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 ).
  26. Turn the ignition switch to ON (II), and then to LOCK (0), then wait at least 40 seconds. Turn the ignition switch to ON (II) again.
  27. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P1673 indicated? 

    YES  -If the MCM was updated, substitute a known-good MCM (see SUBSTITUTING THE MCM ), and recheck. If the MCM was substituted, go to step  1.

    NO  -Go to step 28.

  28. Monitor the OBD STATUS for DTC P1673 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -If the MCM was updated, troubleshooting is complete. If the MCM was substituted, replace the original MCM (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ). If any other Pending or Confirmed DTCs were indicated in step  27, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -

    • If the HDS indicates FAILED: If the MCM was updated, substitute the MCM (see SUBSTITUTING THE MCM ), and recheck. If the MCM was substituted, go to step  1.
    • If the HDS indicates NOT COMPLETED: Go to step  26.
scientia non olet · About LEMON Manuals