DTC Troubleshooting
DTC P1437 (41): MCM Circuit ShortedNOTE:
- Before you troubleshoot, record all freeze data, and review the general troubleshooting information.
- Information marked with an asterisk (*) applies to the 06-07 models.
1. Turn the ignition switch ON (II).
2. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0AA6 (59), P1440 (57), or P15A5 (85) indicated?
YES - Go to the indicated DTC's troubleshooting.
NO - Go to step 3.
3. Turn the ignition switch OFF, and wait 1 minute.
4. Start the engine, and let it idle.
5. Monitor the OBD STATUS for DTC P1437 (41) in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 6.
NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MCM. If the screen indicates NOT COMPLETED, go to step 1.
6. Turn the ignition switch OFF.
7. Turn the battery module switch OFF.
8. Remove the IPU lid.
9. Remove the BCM module.
10. Disconnect the MCM 2OP connector.
11. Connect the BCM module connectors.
12. Turn the ignition switch ON (111, then measure voltage between MCM 20P connector terminal No. 18, No. 19 and body ground within 1 second.
Is there battery voltage on both terminals?
YES - Go to step 22.
NO -
- Repair the connection in the MCM connector, then go to step 13.
- Repair open or short in the wire between the No. 61 +B IMA 2 (10 A) fuse, MCM relay 2, and the MCM, then go to step 13.
13. Turn the ignition switch OFF.
14. Reconnect all connectors.
15. Reinstall the IPU lid, then turn the battery module switch ON.
16. Turn the ignition switch ON (II).
17. Clear the DTC with the HDS.
18. Turn the ignition switch OFF, and wait 1 minute.
19. Start the engine, and let it idle.
20. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1437 (41) indicated?
YES - Check for poor connections or loose terminals at the MCM, then go to step 1.
NO - Go to step 21.
21. Monitor the OBD STATUS for DTC P1437 (41) 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 20, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the DC-DC converter and the MCM, then go to step 1. If the screen indicates NOT COMPLETED, keep the ignition switch ON (II) until a result comes on.
22. Turn the ignition switch OFF.
23. Reconnect all connectors.
24. Reinstall the IPU lid, then turn the battery module switch ON.
25. Update the MCM if it does not have the latest software, or substitute a known-good MCM.
26. Turn the ignition switch OFF, and wait 1 minute.
27. Start the engine, and let it idle.
28. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1437 (41) indicated?
YES - Check for poor connections or loose terminals at DC-DC converter and the MCM. 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 29.
29. Monitor the OBD STATUS for DTC P1437 (41) 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 28, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at DC-DC converter and the MCM. If the MCM was updated, substitute 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.