P16BC

DTC P16BC: Alternator FR Terminal circuit/IGP Circuit Low Voltage

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

1. Check for poor connections or loose terminals at the alternator 4P connector.

Are the connections and terminals OK?

YES - Go to step 2.

NO - Repair the connector or terminals, then go to step 18.

2. Check the alternator mounting surface for corrosion.

Is the mounting surface corroded?

YES - Remove the alternator. Clean all mounting surfaces and reinstall the alternator, then go to step 18.

NO - Go to step 3.

3. Turn the ignition switch ON (II).
4. Clear the DTC with the HDS.
5. Start the engine.
6. 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

7. Hold the engine speed 2,000 rpm (in neutral) for 1 minute.
8. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P16BC indicated?

YES - Go to step 9.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator.

9. Turn the ignition switch OFF.
10. Disconnect the alternator 4P connector.
11. Turn the ignition switch ON (II).




12. Measure voltage between alternator 4P connector terminal No. 1 and body ground.

Is there battery voltage?

YES - Go to step 13.

NO - Repair open in the wire between the alternator (IG1 line) and the No. 3 ALTERNATOR (10 A) fuse in the under-dash fuse/relay box, then go to step 18.




13. Measure voltage between alternator 4P connector terminal No. 4 and body ground.

Is there about 5 V?

YES - Replace the alternator, then go to step 18.

NO - Go to step 14.

14. Turn the ignition switch OFF.
15. Jump the SCS line with the HDS.
16. Disconnect ECM connector B (44P).




17. Check for continuity between alternator 4P connector terminal No. 4 and ECM connector terminal B43.

Is there continuity?

YES - Go to step 27.

NO - Repair open in the wire between the ECM (B43) and the alternator, then go to step 18.

18. Turn the ignition switch OFF.
19. Reconnect all connectors.
20. Turn the ignition switch ON (II).
21. Reset the ECM with the HDS.
22. Do the ECM idle learn procedure.
23. Start the engine.
24. 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

25. Hold the engine speed 2,000 rpm (in neutral) for 1 minute.
26. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P16BC is indicated, check for poor connections or loose terminals at the alternator and the ECM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.

27. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
28. Start the engine.
29. 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

30. Hold the engine speed 2,000 rpm (in neutral) for 1 minute.
31. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P16BC indicated?

YES - Check for poor connections or loose terminals at the alternator and the ECM. If the ECM was updated, substitute a known-good ECM, then go to step 28. If the ECM was substituted, go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.