DTC 12

DTC 12: Motor Driver Module (MCM) Voltage Problem
1. Check to see if the battery module switch is ON.
Is the switch ON?
YES- Go to step 2.
NO- Turn the battery module switch ON.
2. Reset the MCM.
3. Turn the ignition switch ON (II).
4. Watch the IMA system indicator.
Is DTC 79 indicated?
YES- Do the DTC 79 troubleshooting and recheck.
NO- Go to step 5.
5. Watch the IMA system indicator.
Is DTC 74 indicated?
YES- Do the DTC 74 troubleshooting and recheck.
NO- Go to step 6.
6. Watch the IMA system indicator.
Is DTC 12 indicated?
YES- Go to step 8.
NO- Go to step 7.
7. Start the engine, and hold the engine at 4,000 rpm for 2 seconds.
Is DTC 12 indicated?
YES- Replace the battery module.
NO- Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the high voltage connector, high voltage contactor relay, BCM module, battery module and at the MCM.
8. Turn the ignition switch OFF.
9. Turn the battery module switch OFF.
10. Remove the IPU lid.
11. Check for connection at the BCM module C (20P) connector.
Is connection OK ?
YES- Go to step 12.
NO- Repair as necessary.
12. Turn the ignition switch ON (II).





13. Measure voltage between BCM module connector terminals C9 and C10.
Is there about 140 V or more?
YES- Replace the MPI module, the voltage converter module and BCM modules
NO- Go to step 14.
14. Turn the battery module switch ON.
15. Turn the ignition switch ON (II).
16. Measure voltage between the main output terminals on the junction board.
Is there about 140 V or more?
YES- Replace the MPI module, the voltage converter module and BCM module.
NO- Go to step 17.





17. Measure voltage between the high voltage contactor 2P connector terminals No. 1 and No. 2.
Is there battery voltage?
YES- Replace the battery module.
NO- Go to step 18.
18. Check the high voltage contactor control relay.
Is the relay OK?
YES- Go to step 19.
NO- Replace the high voltage contactor control relay.





19. Check for continuity between the high voltage contactor control relay 4P connector terminal No. 3 and body ground.
Is there continuity?
YES- Go to step 20.
NO- Repair open in the wire between the high voltage contactor control relay and G502.
20. Turn the ignition switch ON (II).





21. Measure voltage between MCM connector terminals (A21) and body ground.
Is there battery voltage?
YES- Repair open in the wire between the MCM (A21) and the high voltage contactor control relay.
NO- Substitute a known-good MCM and recheck. If normal voltage is indicated, replace the original MCM.