DTC Troubleshooting

DTC Troubleshooting: P16BB

DTC P16BB: Alternator B Terminal Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

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

2. Clear the DTC with HDS.

3. Start the engine.

4. Check under these conditions:
- A/C on

- Temperature control at maximum cool

- Blower fan at maximum speed

- Rear window defogger on

- Headlights on high beam

5. Hold the engine speed at 2,000 rpm (in neutral) for 1 minute.

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

Is DTC P16BB indicated?
YES - Go to step 7.

NO - Intermittent failure, the system is OK at this time Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box, and check the battery performance.. Testing and Inspection


7. Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box (+B line).

Are the connections and terminals OK?
YES - Go to step 8.

NO - Repair the connectors or terminals, then go to step 9.


8. Check for an open in the wire (+B line) between the alternator and under-hood fuse/relay box (+B line).

Is the harness OK?
YES - Replace the alternator, Removal and Replacement then go to step 9.

NO - Repair open in the wire (+B line) between the alternator and the under-hood fuse/relay box (+B line), then go to step 9.


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

10. Reset the ECM with the HDS.

11. Do the ECM idle learn procedure. ECM Idle Learn Procedure

12. Start the engine.

13. Check under these conditions:
- A/C on

- Temperature control at maximum cool

- Blower fan at maximum speed

- Rear window defogger on

- Headlights on high beam

14. Hold the engine speed at 2,000 rpm (in neutral) for 1 minute.

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

Is DTC P16BB indicated?
YES - Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box, 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.