DTC Troubleshooting

DTC Troubleshooting: P15AB

DTC P15AB: Engine Mount Control Unit Power Source Circuit Low Voltage

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 for Temporary DTCs or DTCs with the HDS.

Is DTC P16C5 indicated?
YES - Do the troubleshooting for the DTC P16C5. P16C5

NO - Go to step 3.


3. Clear the DTC with the HDS.

4. Start the engine, and let it idle 10 seconds.

5. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P15AB indicated?
YES - Go to step 6.

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 body ground (G302).


6. Turn the ignition switch to LOCK (0).

7. Inspect the No. 7 ACG fuse in the driver's under-dash fuse/relay box.

Is the fuse OK?
YES - Go to step 8.

NO - Repair short to ground in the wire between the No. 7 ACG fuse and engine mount control unit 16P connector terminal No. 5. Also replace the No. 7 ACG fuse, then go to step 14.


8. Check for poor connections or loose terminals at the engine mount control unit 16P connector.

Are the connections and terminals OK?
YES - Go to step 9.

NO - Repair the connections or terminals, then go to step 14.


9. Disconnect engine mount control unit 16P connector.

10. Turn the ignition switch to ON (II).

11. Measure the voltage between engine mount control unit 16P connector terminal No. 5 and body ground.

Is there battery voltage?
YES - Go to step 12.

NO - Repair open in the wire between the No. 7 ACG fuse and engine mount control unit 16P connector terminal No. 5, then go to step 14.






12. Turn the ignition switch to LOCK (0).

13. Check for continuity between engine mount control unit 16P connector terminal No. 3 and body ground.

Is there continuity?
YES - Replace the engine mount control unit, Service and Repair then go to step 14.

NO - Repair open in the wire between engine mount control unit 16P connector terminal No. 3 and body ground (G302), then go to step 14.






14. Reconnect all connectors.

15. Turn the ignition switch to ON (II).

16. Clear the DTC with the HDS.

17. Start the engine, and let it idle 10 seconds.

18. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P15AB indicated?
YES - Check for poor connections or loose terminals at the engine mount control unit and body ground (G302), then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.