Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSFORD2018F-450 SUPER DUTY LARIAT, 4D PICKUP CREW CAB, 4WDREPAIR AND DIAGNOSIS (SINGLE PAGE)ACCESSORIES & EQUIPMENTCOMMUNICATION DEVICESMULTIFUNCTION ELECTRONIC MODULESDIAGNOSIS AND TESTINGGENERIC FUNCTION MODULE 2 (GFM2)SYMPTOM CHART
2018 Ford F-450 Super Duty Lariat, 4D Pickup Crew Cab, 4WD
Symptom Chart
2018 Ford F-450 Super Duty Lariat, 4D Pickup Crew Cab, 4WDSECTION Symptom Chart
| Symptom | Possible Sources | Action |
|---|---|---|
| No GFM2 controlled systems are operational | Refer to pinpoint test. | GO to Pinpoint Test A |
| Some GFM2 controlled systems are operational | Upfitter fuses Upfitter relays Upfitter wiring Upfitter devices GFM2 |
REFER to upfitter wiring and check upfitter relays, wiring and devices. If no concerns are found with upfitter relays, wiring or devices, INSTALL a new GFM2. REFER to: Generic Function Module 2 (GFM2) . |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.