DTC Troubleshooting

DTC P0A3C (39): MCM Overheating

NOTE:
- Before you troubleshoot, record all freeze data, and review the general troubleshooting information.
- If the IPU module fan duct is blocked, DTC POA3C may be detected.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1448 (63) indicated?

YES - Do the troubleshooting for DTC P1448 (63).

NO - Go to step 4.

4. Check the MPI TEMPERATURE in the DATA LIST with the HDS.

Is more than 212 °F (100 °C) indicated?

YES - Go to step 7.

NO - Go to step 5.

5. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: IPU MODULE FAN SPEED VSS (MCM) Motor Speed (MCM)
6. Check the MPI TEMPERATURE in the DATA LIST with the HDS.

Is more than 212 °F (100 °C) indicated?

YES - Go to step 7.

NO - Intermittent failure, the system is OK at this time. Check for a blockage at the IPU module fan inlet duct.

7. Check the IPU module air duct or IPU module fan for disconnections, damage, or obstructions, and check the IPU lid installation.

Are the IPU module air duct, the IPU module fan, and the IPU lid OK?

YES - Go to step 12.

NO - Repair the IPU module air duct, the IPU module fan, or the IPU lid as necessary, then go to step 8.

8. Turn the ignition switch ON (II).
9. Clear the DTC with the HDS.
10. Check for Temporary DTCs or DTCs with the HDS.

Is DTC POA3C (39) indicated?

YES - Check for poor connections or loose terminals at the MCM and the IPU module fan, then go to step 1.

NO - Go to step 11.

11. Monitor the OBD STATUS for DTC POA3C (39) in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 10, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the MCM and the IPU module fan. If the screen indicates NOT COMPLETED, keep the ignition switch ON (II) until a result comes on.

12. Update the MCM if k does not have the latest software, or substitute a known-good MCM.
13. Check for Temporary DTCs or DTCs with the HDS.

Is DTC POA3C (39) indicated?

YES - Check for poor connections or loose terminals at the MCM and the. IPU module fan. If the MCM was updated, substitute a known-good MCM, then recheck. If the MCM was substituted, go to step 1.

NO - Go to step 14.

14. Monitor the OBD STATUS for DTC POA3C (39) in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - If the MCM was updated, troubleshooting is complete. If the MCM was substituted, replace the original MCM. If any other Temporary DTCs or DTCs were indicated in step 13, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the MCM and the IPU module fan. If the MCM was updated, substituted a known-good MCM, then recheck. If the MCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep the ignition switch ON (II) until a result comes on.