DTC Troubleshooting: P16BC (116) (K20Z: M/T)

DTC Troubleshooting: P16BC (116)

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 terminal OK?


YES - Go to 2.


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


2.Check the alternator mounting surface for corrosion.

Is the mounting surface corroded?


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


NO - Go to 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 (min-1) (in Park or neutral) for 1 minute.

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

Is DTC P16BC indicated?


YES - Go to 9.


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


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 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 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 18.


NO - Go to 14.


14.Turn the ignition switch OFF.

15.Jump the SCS line with the HDS.

16.Disconnect ECM/PCM connector B (44P).

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

 

Is there continuity?


YES - Go to 27.


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


18.Turn the ignition switch OFF.

19.Reconnect all connectors.

20.Turn the ignition switch ON (II).

21.Reset the ECM/PCM with the HDS.

22.Do the ECM/PCM 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 (min-1) (in Park or 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/PCM, 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


27.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/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 (min-1) (in Park or neutral) for 1 minute.

31.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/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n