Pinpoint Test E: P065B: Notes
Diagnostic Overview
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Service Information for more information.
Refer to Charging System for schematic and connector information.
Normal Operation and Fault Conditions
With the engine running, the PCM monitors and expects to receive a valid generator monitor (GENMON) signal with a duty cycle greater than 5% and less than 98%. The PCM also monitors the state of the generator command (GENCMD) signal line to make sure it is not stuck high or stuck low. A DTC sets if the GENMON or GENCMD signal fluctuates between out-of-valid range, stuck high, stuck low, or some combination and normal. When the engine speed is greater than 2, 000 Revolutions Per Minute (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.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P065B | Generator Control Circuit Range/Performance | The PCM sets this DTC if the input frequency was continuously less than 80 Hz or more than 200 Hz. Additionally, if the signal shows a faulted condition the PCM tracks the fluctuations between faulted and normal conditions. This DTC can also set if the fluctuations occur frequently within a short amount of time. This fault can be caused by intermittent wiring connections. |
Possible Sources
- Battery
- Engine, generator and battery grounds
- Fuses
- Generator
- PCM
- Wiring, terminals or connectors
Visual Inspection and Diagnostic Pre-checks
- Inspect for loose or corroded connections.
- Inspect high current BJB for loose or corroded connections.