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Home >> Honda >> 2012 >> Odyssey EX >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Active Control Engine Mount (ACM) System >> DTC Troubleshooting >> DTC P16C5: Engine Mount Actuator Control Power Circuit Stuck ON
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DTC P16C5: Engine Mount Actuator Control Power Circuit Stuck ON

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. Check the ACM UNIT SUPPLY VOLTAGE and ACM CONTROL RELAY in the DATA LIST with the HDS.

    Does the ACM UNIT SUPPLY VOLTAGE indicate battery voltage when the ACM CONTROL RELAY indicates OFF? 

    YES  -Go to step 3.

    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.

  3. Turn the ignition switch to LOCK (0).
  4. Disconnect the active control engine mount (ACM) control relay.
  5. Disconnect engine mount control unit 16P connector.
  6. Check for continuity between engine mount control unit 16P connector terminal No. 16 and body ground.
    Fig 1: Checking Continuity Between Engine Mount Control Unit 16P Connector Terminal No. 16 And Body Ground
    G06966336Courtesy 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. 16 and active control engine mount (ACM) control relay 4P socket terminal No. 4, then go to step  12.

    NO  -Go to step 7.

  7. Turn the ignition switch to ON (II).
  8. Measure the voltage between engine mount control unit 16P connector terminal No. 6 and body ground.
    Fig 2: Measuring Voltage Between Engine Mount Control Unit 16P Connector Terminal No. 6 And Body Ground
    G06966337Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Repair a short to power in the wire between engine mount control unit 16P connector terminal No. 6 and active control engine mount (ACM) control relay 4P socket terminal No. 2, then go to step  12.

    NO  -Go to step 9.

  9. Turn the ignition switch to LOCK (0).
  10. Reconnect active control engine mount (ACM) control relay.
  11. Measure the voltage between engine mount control unit 16P connector terminal No. 6 and body ground.
    Fig 3: Measuring Voltage Between Engine Mount Control Unit 16P Connector Terminal No. 6 And Body Ground
    G06966338Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Replace the active control engine mount (ACM) control relay, then go to step 12.

    NO  -Replace the engine mount control unit (see ENGINE MOUNT CONTROL UNIT REPLACEMENT  ), then go to step 12.

  12. Reconnect all connectors.
  13. Turn the ignition switch to ON (II).
  14. Clear the DTC with the HDS (see DTC CLEAR  ).
  15. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P16C5 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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