DTC Troubleshooting
DTC Troubleshooting: 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 Initial Inspection and Diagnostic Overview.
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 connections or terminals, then go to step 18.
2. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
3. Clear the DTC with the HDS.
4. Start the engine.
5. 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
6. Hold the engine speed 2,000 rpm (in P or N) for 1 minute.
7. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P16BC indicated?
YES -
Go to step 8.
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator.�
8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
9. Disconnect the alternator 4P connector.
10. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
11. Measure the voltage between alternator 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 12.
NO -
Repair an open in the wire between the alternator (IG1 line) and the No. 13 ACG (15 A) fuse in the driver's under-dash fuse/relay box, then go to step 17.
12. Measure the voltage between alternator 4P connector terminal No. 4 and body ground.
Is there about 5 V?
YES -
Replace the alternator Removal and Replacement, then go to step 17.
NO -
Go to step 13.
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
14. Jump the SCS line with the HDS.
15. Disconnect PCM connector C (49P).
16. Check for continuity between alternator 4P connector terminal No. 4 and PCM connector terminal C44.
Is there continuity?
YES -
Go to step 26.
NO -
Repair an open in the wire between the PCM(C44) and the alternator, then go to step 17.
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
18. Reconnect all connectors.
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
20. Reset the PCM with the HDS.
21. Do the PCM idle learn procedure PCM Idle Learn Procedure.
22. Start the engine.
23. 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
24. Hold the engine speed at 2,000 rpm (in P or N) for 1 minute.
25. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P16BC indicated?
YES -
Check for poor connections or loose terminals at the alternator and the PCM, 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.�
26. Reconnect all connectors.
27. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
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 P or N) for 1 minute.
31. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P16BC indicated?
YES -
Check for poor connections or loose terminals at the alternator and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 28. If the PCM was substituted, go to step 1.
NO -
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�