P0625 Generator Field F Terminal Circuit Low

OBD2 Code: P0625

Description: Generator Field F Terminal Circuit Low

Definition: This code indicates that the powertrain control module (PCM) has detected a low voltage condition in the generator field “F” terminal circuit. The “F” terminal is responsible for controlling the alternator’s output by regulating the current flow to the rotor, which affects the magnetic field and subsequently, the charging system’s performance.

P0625 – Generator Field “F” Terminal Circuit Low

Typical Severity: Moderate

Common Causes

P0625 – Generator Field “F” Terminal Circuit Low

Common causes:

• Faulty generator field control module
• Open or short circuit in the wiring for the generator field terminal
• Loose or poor connection at the generator field terminal
• Defective generator (alternator)

 

Common Misdiagnosis

OBD2 Code: P0625

Description: Generator Field F Terminal Circuit Low

Common Misdiagnosis: Replacing the alternator without checking for wiring issues or poor connections in the circuit.

 

Common Diagnostic Steps

OBD2 Code: P0625

Description: Generator Field F Terminal Circuit Low

Common Diagnostic Steps:

• Check the battery voltage and ensure it is fully charged.
• Inspect the generator (alternator) connections for corrosion or looseness.
• Examine the wiring harness and connectors for damage or poor connections in the generator field circuit.
• Test the generator output to ensure it is within specifications.
• Use a multimeter to check for continuity in the field terminal circuit from the PCM to the alternator.
• Verify that there are no blown fuses related to the charging system.
• If equipped, inspect and test any fusible links associated with the alternator circuit.
• Perform a diagnostic scan to check for additional trouble codes that may indicate other issues with the charging system or PCM.
• If all checks pass, consider testing or replacing the alternator if it appears faulty based on output tests and visual inspection.