DTC Troubleshooting: P16BB (116) (K20Z: M/T)

DTC Troubleshooting: P16BB (116)

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.

1.Turn the ignition switch 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 (min-1) (in Park or neutral) for 1 minute.

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

Is DTC P16BB indicated?


YES - Go to 7.


NO - Intermittent failure, 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.n


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 8.


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

8.Check for an open in the wire between the alternator and under-hood fuse/relay box at the starter subharness.

Is the harness OK?


YES - Replace the alternator, then go to 9.


NO - Repair open in the wire between the alternator and the under-hood fuse/relay box, then go to 9.


9.Turn the ignition switch ON (II).

10.Reset the ECM/PCM with the HDS.

11.Do the ECM/PCM 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 (min-1) (in Park or neutral) for 1 minute.

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

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P16BB is indicated, check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n