FixVault

Pinpoint Test A: GFM2 (Generic Function Module 2) Controlled Systems Are Inoperable

  1. NOTE: Except for GFM2 power, ground and HS-CAN, all wiring is provided by an upfitter. REFER to upfitter documentation for wiring and system operation.

    Refer to Wiring Diagrams CUSTOMER ACCESS for schematic and connector information.

    Normal Operation and Fault Conditions 

    REFER to: Generic Function Module 2 (GFM2) .

    Possible Sources 

    • Wiring, terminals or connectors
    • Fuse(s)
    • Auxiliary relays
    • Auxiliary devices
    • GFM2

    Visual Inspection and Pre-checks 

    • Verify AJB fuse F47 (10A).
    • Inspect the GFM2 for loose or corroded connections.

  2. A1 CHECK FOR CHARGING SYSTEM DIAGNOSTIC TROUBLE CODES (DTCS) SET IN OTHER MODULES

    • Ignition ON.

    • Connect the diagnostic tool.

    • Using a diagnostic scan tool, retrieve all Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Are any charging system DTCs recorded? 

    Yes  DIAGNOSE the charging system concern. Refer to the appropriate Battery and Charging System article.
    No  GO to  A2
  3. A2 CHECK THE BATTERY CONDITION AND STATE OF CHARGE

    • Check the battery condition and verify the battery is fully charged. REFER to: Battery .

    Is the battery OK and fully charged? 

    Yes  GO to  A3
    No  If the battery is discharged, DIAGNOSE the cause of the low battery condition. Refer to the appropriate Battery and Charging System article. If the battery condition fails, INSTALL a new battery. REFER to: Battery - Vehicles With: Dual Batteries .
  4. A3 CHECK GFM2 (GENERIC FUNCTION MODULE 2) POWER

    • Ignition OFF.

    • Disconnect GFM2 C290A.

    • Ignition ON.

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD568062Courtesy of FORD MOTOR COMPANY
      GFD568064Courtesy of FORD MOTOR COMPANY
      GFD568063Courtesy of FORD MOTOR COMPANY

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C290A-1
      GFD568064Courtesy of FORD MOTOR COMPANY
      Ground

    Is the voltage within 0.5 volt of the recorded battery voltage? 

    Yes  GO to  A4
    No  VERIFY AJB fuse F471 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short to ground.
  5. A4 CHECK GFM2 (GENERIC FUNCTION MODULE 2) GROUND

    • Ignition OFF.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C290A-4
      GFD568065Courtesy of FORD MOTOR COMPANY
      Ground

    Is the resistance less than 3 ohms? 

    Yes  INSTALL a new GFM2. REFER to the appropriate Service Information.
    No  REPAIR the circuit.