Inspection and Verification

WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .

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 Customer Access for schematic and connector information.

Visually inspect for obvious signs of mechanical or electrical damage.
Verify BJB fuse F91 (10A).
Check the battery condition and state of charge. REFER to: Battery .
If an obvious cause for an observed or reported concern is found, correct the cause before proceeding to the next step.
Using a diagnostic scan tool, RETRIEVE all CM DTC.
If the GFM2 fails the network test, REFER to: Communications Network .
If any diagnostic trouble codes (DTCs) are retrieved, REFER to DTC Charts
If no diagnostic trouble codes (DTCs) were retrieved, REFER to Symptom Chart