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 the HDS.

3. Start the engine.

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

- Temperature control on 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 P or N) for 1 minute.

6. Check for Pending or Confirmed 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 B terminal and the under-hood fuse/relay box terminal (T101).

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

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


8. Check for an open in the cable (+B line) between the alternator B terminal and under-hood fuse/relay box terminal (T101).

Is the cable OK?
YES - Replace the alternator, then go to step 9.

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


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

10. Reset the PCM with the HDS.

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

12. Start the engine.

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

- Temperature control on 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 P or N) for 1 minute.

15. Check for Pending or Confirmed 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 Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.