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 connectors OK?

YES | - | Go to Step 2 .
NO | - | Reconnect the connector, then go to Step 18 .

1. Turn the ignition switch ON (II).

1. Clear the DTC with the HDS.

1. Start the engine.

1. 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

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

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

Is DTC P16BC indicated?

YES | - | Go to Step 8 .
NO | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the alternator.■

1. Turn the ignition switch OFF.

1. Disconnect the alternator 4P connector.

1. Turn the ignition switch ON (II).

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

Is there battery voltage?

YES | - | Go to Step 12 .
NO | - | Repair open in the wire between the alternator (IG1 line) and the No. 18 ACG (15 A) fuse in the under-dash fuse/relay box, then go to Step 18 .

1. 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 13 .

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

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

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

1. Check for coutinuity between ECM/PCM connector terminal B13 and body ground.

Is there continuity?

YES | - | Go to Step 26 .
NO | - | Repair open in the wire between the ECM/PCM (B13) and the alternator, then go to Step 18 .

1. Reconnect all connectors.

1. Turn the ignition switch ON (II).

1. Reset the ECM/PCM with the HDS.

1. Do the ECM/PCM idle learn procedure.

1. Start the engine.

1. 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

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

1. 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 Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | Troubleshooting is complete.■

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

1. Start the engine.

1. 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

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

1. 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 Step 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. ■