Is the concern still present?
Yes | CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new PCM. REFER to: Powertrain Control Module (PCM) (303-14C Electronic Engine Controls - 5.0L 32V Ti-VCT/5.0L Ti-VCT V8 (308kW/418PS), Removal and Installation). CLEAR all Diagnostic Trouble Codes (DTCs) in all modules. |
|---|---|
No | The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues. |
DTC P0625 or P0626
Refer to Wiring Diagrams Cell 12 for schematic and connector information.
Normal Operation and Fault Conditions
The PCM monitors the generator output via the generator monitor (GENMON) circuit (generator field terminal circuit). If the PCM cannot read the GENMON 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 GENMON duty cycle of 3% or less indicates a short to ground fault is present and results in DTC P0625 setting in the PCM . A GENMON duty cycle of 98% or more indicates an open or short to voltage fault is present and results in DTC P0626 setting in the PCM.
Diagnostic Trouble Code (DTC) Fault Trigger Conditions
DTC | Description | Fault Trigger Conditions |
|---|---|---|
P0625 Generator Field Terminal Circuit Low | The PCM sets this DTC if the GENMON 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. | |
P0626 Generator Field Terminal Circuit High | The PCM sets this DTC if the GENMON 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 Generator PCM Wiring, terminals or connectors
Visual Inspection and Diagnostic Pre-checks
Inspect for abnormal ignition-off current drain(s). Inspect the high current BJB for loose or corroded connections.
PINPOINT TEST G : DTC P0625 OR P0626
G1 CHECK THE BATTERY CONDITION
Check the battery condition and state of charge. REFER to: Battery (414-01) .
Does the battery pass the condition test?
Yes | GO to G2 |
|---|---|
No | CHARGE or INSTALL a new battery as necessary. REFER to: Battery (414-01 Battery, Mounting and Cables, Removal and Installation). |
G2 CHECK THE GENERATOR CONNECTIONS
Ignition OFF. Disconnect all of the generator connectors and inspect for:
corrosion (install new connector or terminals – clean module pins) damaged or bent pins – install new terminals/pins pushed-out pins – install new pins as necessary
Reconnect the generator connectors. Make sure they seat and latch correctly. Measure and record:
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.