Pinpoint Test H : DTC P163C, P163D: Notes
DTC P163C, P163D
Refer to Charging System for schematic and connector information.
Normal Operation and Fault Conditions
The PCM monitors the generator output via the generator monitor (GENMON2) circuit (generator field terminal circuit). If the PCM cannot read the GENMON2 circuit due to an open or short to ground, when the engine speed is greater than 2, 000 rpm, the generator defaults to a steady voltage of 13.5 volts and the PCM sends a request to the IPC to illuminate the charging system warning indicator. A GENMON2 duty cycle of 3% or less indicates a short to ground fault is present and results in DTC P0625 setting in the PCM A GENMON2 duty cycle of 98% or more indicates an open or short to voltage fault is present and results in DTC P163C setting in the PCM.
Diagnostic Trouble Code (DTC) Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P163C | Generator "B" Field Terminal Circuit Low | The PCM sets this DTC if the GENMON2 circuit is shorted to ground, the "A" sense circuit is open or the B+ circuit is open. This DTC also sets by a faulted PCM or generator. |
| P163D | Generator "B" Field Terminal Circuit High | The PCM sets this DTC if the GENMON2 circuit is open or shorted to power. This DTC can also be set by a faulted PCM or generator. |
Possible Sources
- Battery
- Fuses or Fusible Links
- Secondary Generator
- PCM
- Wiring, terminals or connectors
Visual Inspection and Diagnostic Pre-checks
- Inspect for abnormal ignition-off current drain(s).
- Inspect the BJB for loose or corroded connections.