DTC Troubleshooting
DTC Troubleshooting: P16C4
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 Initial Inspection and Diagnostic Overview.
1. Turn the ignition switch to ON (II).
2. Check the ACM UNIT SUPPLY VOLTAGE in the DATA LIST with the HDS.
Is there battery voltage?
YES -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the engine mount control unit and the driver's under-dash fuse/relay box (active control engine mount (ACM) control relay).�
NO -
Go to step 3.
3. Turn the ignition switch to LOCK (0).
4. Inspect the No. B14 ACM (10 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to step 9.
NO -
Go to step 5.
5. Remove the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal/Installation.
6. Disconnect driver's under-dash fuse/relay box connector G (13P).
7. Disconnect the engine mount control unit 16P connector.
8. Check for continuity between engine mount control unit 16P connector terminal No. 6 and body ground.
Is there continuity?
YES -
Repair a short to ground in the wire between engine mount control unit 16P connector terminal No. 6 and the driver's under-dash fuse/relay box (ACM control relay). Also replace the No. B14 ACM (10 A) fuse, then go to step 25.
NO -
Check the driver's under-dash fuse/relay box, and replace it if needed. Also replace the No. B14 ACM (10 A) fuse, then go to step 25.
9. Remove the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal/Installation.
10. Disconnect the engine mount control unit 16P connector.
11. Turn the ignition switch to ON (II).
12. Measure the voltage between engine mount control unit 16P connector terminal No. 16 and body ground.
Is there battery voltage?
YES -
Go to step 16.
NO -
Go to step 13.
13. Turn the ignition switch to LOCK (0).
14. Disconnect driver's under-dash fuse/relay box connector G (13P).
15. Check for continuity between engine mount control unit 16P connector terminal No. 16 and driver's under-dash fuse/relay box connector G (13P) terminal No. 7.
Is there continuity?
YES -
Replace the driver's under-dash fuse/relay box; USA models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation, Canada models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada models), then go to step 25.
NO -
Repair an open in the wire between engine mount control unit 16P connector terminal No. 16 and driver's under-dash fuse/relay box connector G terminal No. 7, then go to step 25.
16. Turn the ignition switch to LOCK (0).
17. Connect engine mount control unit 16P connector terminal No. 16 and body ground with a jumper wire.
18. Turn the ignition switch to ON (II).
19. Measure the voltage between engine mount control unit 16P connector terminal No. 6 and body ground.
Is there battery voltage?
YES -
Go to step 23.
NO -
Go to step 20.
20. Turn the ignition switch to LOCK (0).
21. Disconnect driver's under-dash fuse/relay box connector G (13P).
22. Check for continuity between engine mount control unit 16P connector terminal No. 6 and driver's under-dash fuse/relay box connector G (13P) terminal No. 4.
Is there continuity?
YES -
Replace the driver's under-dash fuse/relay box; USA models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation, Canada models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada models), then go to step 25.
NO -
Repair an open in the wire between engine mount control unit 16P connector terminal No. 6 and driver's under-dash fuse/relay box connector G terminal No. 4, then go to step 25.
23. Turn the ignition switch to LOCK (0).
24. Check for continuity between engine mount control unit 16P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Replace the engine mount control unit Service and Repair, then go to step 25.
NO -
Repair an open in the wire between engine mount control unit 16P connector terminal No. 4 and body ground G302, then go to step 25.
25. Reconnect all connectors.
26. Turn the ignition switch ON (II).
27. Clear the DTC with the HDS.
28. 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 driver's under-dash fuse/relay box (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.�