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DTC P1673 (22): Motor Control Module (MCM) Relay Stays Activated

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
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 (55).
  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 (22) 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 DISCONNECTING THE MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR  ).
  7. Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION  ).
  8. Remove MCM relay 1 (A).
    Fig 1: Identifying MCM Relay 1
    G06429887Courtesy 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 3 And 4
    G00496910Courtesy of AMERICAN HONDA MOTOR CO., INC.

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

    YES  -go to step 10.

    NO  -go to step  11.

  10. Check 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
    G06429889Courtesy 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 DISCONNECTING THE MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR  ).
  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 (22) indicated? 

    YES  -go to step  1.

    NO  -go to step 21.

  21. Monitor the OBD STATUS for DTC P1673 (22) in the DTCs MENU with the HDS.

    Does the screen 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 screen indicates FAILED, go to step  1. If the screen 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 DISCONNECTING THE MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR  ).
  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 (22) 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 (22) in the DTCs MENU with the HDS.

    Does the screen 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 screen 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 screen indicates NOT COMPLETED: go to step  26.
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