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Home >> Honda >> 2017 >> Odyssey EX >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Active Control Engine Mount (ACM) System >> DTC Troubleshooting >> DTC P16C4: Engine Mount Actuator Control Power Circuit Stuck OFF
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DTC P16C4: Engine Mount Actuator Control Power Circuit Stuck OFF

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshots, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION  ).
  1. Turn the ignition switch to ON (II).
  2. Clear the DTCs with the HDS (see DTC CLEAR  ).
  3. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P16C4 indicated? 

    YES  -Go to step 4.

    NO  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the engine mount control unit and the active control engine mount (ACM) control relay.

  4. Turn the ignition switch to LOCK (0).
  5. Inspect the No. D3 (10 A) and the No. D20 (7.5 A) fuses in the passenger's under-dash fuse/relay box.

    Are the fuses OK? 

    YES  -Go to step  14.

    NO  -

    • If the No. D3 fuse is blown, go to step 6.
    • If the No. D20 fuse is blown, go to step  10.
  6. Remove the glove box (see GLOVE BOX REMOVAL/INSTALLATION ).
  7. With navigation: Remove the stereo amplifier (see AUDIO DISPLAY UNIT REMOVAL/INSTALLATION ).
  8. Disconnect engine mount control unit 16P connector.
  9. Check for continuity between engine mount control unit 16P connector terminal No. 6 and body ground.
    Fig 1: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 6 And Body Ground
    G06966331Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire between engine mount control unit 16P connector terminal No. 6 and passenger's under-dash fuse/relay box terminal No. A4. Also replace the No. D3 (10 A) fuse, then go to step  21.

    NO  -Replace the engine mount control unit (see ENGINE MOUNT CONTROL UNIT REPLACEMENT  ). Also replace the No. D3(10 A) fuse, then go to step  21.

  10. Remove the glove box (see GLOVE BOX REMOVAL/INSTALLATION ).
  11. With navigation: Remove the stereo amplifier (see AUDIO DISPLAY UNIT REMOVAL/INSTALLATION ).
  12. Disconnect engine mount control unit 16P connector.
  13. Check for continuity between engine mount control unit 16P connector terminal No. 9 and body ground.
    Fig 2: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 9 And Body Ground
    G06966332Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire between engine mount control unit 16P connector terminal No. 9 and passenger's under dash fuse/relay box terminal No. A6. Also replace the No. D20 (7.5 A) fuse, then go to step  21.

    NO  -Replace the engine mount control unit (see ENGINE MOUNT CONTROL UNIT REPLACEMENT  ). Also replace the No. D20 (7.5 A) fuse, then go to step  21.

  14. Test the active control engine mount (ACM) control relay in the passenger's under-dash fuse/relay box (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Leave the relay disconnected and go to step 15.

    NO  -Replace the active control engine mount (ACM) control relay, then go to step  18.

  15. Remove the glove box (see GLOVE BOX REMOVAL/INSTALLATION ).
  16. With navigation: Remove the stereo amplifier (see AUDIO DISPLAY UNIT REMOVAL/INSTALLATION ).
  17. Disconnect engine mount control unit 16P connector.
  18. Check for continuity between engine mount control unit 16P connector terminal No. 6 and passenger's under-dash fuse/relay box terminal No. A4.
    Fig 3: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 6 And Passenger's Under-Dash Fuse/Relay Box Terminal No. A4
    G06966333Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 19.

    NO  -Repair an open in the wire between engine mount control unit 16P connector terminal No. 6 and passenger's under-dash fuse/relay box terminal No. A4, then go to step  21.

  19. Check for continuity between engine mount control unit 16P connector terminal No. 16 and passenger's under-dash fuse/relay box terminal No. A1.
    Fig 4: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 16 And Passenger's Under-Dash Fuse/Relay Box Terminal No. A1
    G06966334Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 20.

    NO  -Repair an open in the wire between engine mount control unit 16P connector terminal No. 16 and passenger's under-dash fuse/relay box terminal No. A1, then go to step  21.

  20. Check for continuity between engine mount control unit 16P connector terminal No. 9 and passenger's under-dash fuse/relay box terminal No. A6.
    Fig 5: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 9 And Passenger's Under-Dash Fuse/Relay Box Terminal No. A6
    G06966335Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Replace the engine mount control unit (see ENGINE MOUNT CONTROL UNIT REPLACEMENT  ), and reinstall the relay, then go to step 21.

    NO  -Repair an open in the wire between engine mount control unit 16P connector terminal No. 9 and passenger's under-dash fuse/relay box terminal No. A6, then go to step 21.

  21. Reconnect all connectors.
  22. Turn the ignition switch ON (II).
  23. Clear the DTC with the HDS.
  24. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P16C4 indicated? 

    YES  -Check for poor connections or loose terminals at the engine mount control unit and the active control engine mount (ACM) control relay, 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 .

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