DTC 48
DTC P0A94 (48): DC-DC Converter Output Low Voltage1. Turn the ignition switch ON (II).
2. Check for IMA system Temporary DTCs or DTCs with the HDS.
Is DTC U1221 (35) or P0562 (94) indicated?
YES - Do the troubleshooting for DTC U1221 (35), or DTC P0562 (94).
NO - Go to step 3.
3. Check under these conditions:
^ Headlights on high beam
^ Blower fan at maximum speed
^ Rear window defogger on
4. Start the engine, and let it idle 2 minutes.
5. Monitor the OBD STATUS for DTC P0A94 (48) 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, system is OK at this time. Check for poor connections or loose terminals at the DC-DC converter, the +B terminal (on the under-hood fuse/relay box), and the MCM. If the screen indicates NOT COMPLETED, go to step 3 and recheck.
6. Check the DC-DC CONVERTER INFORMATION in the DATA LIST with the HDS.
Does the screen indicate NORMAL?
YES - Go to step 7.
NO - Replace the DC-DC converter, then go to step 15.
7. Start the engine.
8. Measure voltage between the 12 V battery terminals.
9. Compare the 12 V battery voltage and the MCM BACK UP VOLTAGE in the DATA LIST with the HDS.
Is there more than 2.2 V difference between the 12 V battery voltage and MCM BACK UP VOLTAGE?
YES - Go to step 23.
NO - Go to step 10.
10. Turn the ignition switch OFF.
11. Check the under-hood fuse/relay box +B terminal (A) (BLK wire) connection.
Is the connection OK?
YES - Go to step 13.
NO - Repair the connection in the wire +B terminal at the under-hood fuse/relay box, then go to step 15.
12. Turn the battery module switch OFF.
13. Remove the IPU lid.
14. Check the +B connector (A) on the DC-DC converter.
Is the connection OK?
YES - Go to step 15.
NO - Repair the +B connector on the DC-DC converter as necessary, then go to step 15.
15. Reconnect all connectors.
16. Reinstall the IPU lid, then turn the battery module switch ON.
17. Turn the ignition switch ON (II).
18. Reset the MCM with the HDS.
19. Check under these conditions:
^ Headlights on high beam
^ Blower fan at maximum speed
^ Rear window defogger on
20. Start the engine, and let it idle 2 minutes.
21. Check for IMA system Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC P0A94 is indicated, check for poor connections or loose terminals at the DC-DC converter, under-hood fuse/relay box, and the MCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO - Go to step 22.
22. Monitor the OBD STATUS for DTC P0A94 (48) in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the DC-DC converter, +B terminal (on the under-hood fuse/relay box), and the MCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 19 and recheck.
23. Reinstall the IPU lid, then turn the battery module switch ON.
24. Update the MCM if it does not have the latest software, or substitute a known-good MCM.
25. Check under these conditions:
^ Headlights on high beam
^ Blower fan at maximum speed
^ Rear window defogger on
26. Start the engine, and let it idle 2 minutes.
27. Check for IMA system Temporary DTCs or DTCs with the HDS.
Is DTC P0A94 (48) indicated?
YES - Check for poor connections or loose terminals at the DC-DC converter, the +B terminal (on the under-hood fuse/relay box), and the MCM. If the MCM was updated, substitute a known-good MCM, then go to step 25. If the MCM was substituted, go to step 1.
NO - If no Temporary DTCs or DTCs are indicated, go to step 28. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
28. Monitor the OBD STATUS for DTC P0A94 (48) 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.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the DC-DC converter, the +B terminal (on the under-hood fuse/relay box), and the MCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 25.