DTC Troubleshooting: P16BC (116)

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

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

Are the connections OK?


YES - Go to 2.


NO - Reconnect the connector, then go to 18.


2.Turn the ignition switch ON (II).

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 at 2,000 rpm (min-1) (in Park or neutral) for 1 minute.

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

Is DTC P16BC indicated?


YES - Go to 8.


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


8.Turn the ignition switch OFF.

9.Disconnect the alternator 4P connector.

10.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Go to 12.


NO - Repair open in the wire between the alternator (IG1 line) and the No. 4 ACG (10 A) fuse in under-dash fuse/relay box, then go to 18.


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

 

Is there about 5 V?


YES - Replace the rear housing assembly of alternator, then go to 18.


NO - Go to 13.

13.Turn the ignition switch OFF.

14.Jump the SCS line with the HDS.

15.Disconnect ECM/PCM connector B (24P).

16.Connect alternator 4P connector terminal No. 4 to body ground with a jumper wire.

 

17.Check for continuity between ECM/PCM connector terminal B13 and body ground.

 

Is there continuity?


YES - Go to 26.


NO - Repair open in the wire between the ECM/PCM (B13) and the alternator, then go to 18.

18.Turn the ignition switch ON (II).

19.Reconnect all connectors.

20.Reset the ECM/PCM with the HDS.

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

25.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 teminals 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

26.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM .

27.Start the engine.

28.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

29.Hold the engine speed at 2,000 rpm (min-1) (in Park or neutral) for 1 minute.

30.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