DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P16BB

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 How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS.

-3. Start the engine.

-4. Check under these conditions:
* A/C on
* Temperature control at maximum cool
* Blower fan at maximum speed
* Headlights on high beam
* Rear window defogger on

-5. Hold the engine speed at 2,000 rpm (in neutral) for 1 minute.

-6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P16BB indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box. Also check the battery performance.

2. +B terminal check:

+B terminal check
-1. 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 step 3.
-NO- Repair the connections or the terminals, then do the repair verification.

3. Open wire check (+B line):

Open wire check (+B line)
-1. Check for an open in the wire between the alternator and the under-hood fuse/relay box at the engine harness.

Is the harness OK?
-YES- Replace the alternator Removal and Replacement, then do the repair verification.
-NO- Repair an open in the +B wire between the alternator and the under-hood fuse/relay box, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to ON (II).

-2. Reset the ECM with the HDS. How To Troubleshoot The Fuel And Emissions Systems

-3. Do the ECM idle learn procedure. ECM/PCM Idle Learn Procedure

-4. Start the engine.

-5. Check under these conditions:
* A/C on
* Temperature control at maximum cool
* Blower fan at maximum speed
* Headlights on high beam
* Rear window defogger on

-6. Hold the engine speed at 2,000 rpm (in neutral) for 1 minute.

-7. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P16BB indicated?
-YES- Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box, 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.