Diagnostic Aids
Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:
- Fuel Pump Relay
- Inertia Fuel Shutoff (IFS) Switch
- Wiring Harness Circuits (B+, FP, FPM, FP PWR, GND, LFP & VPWR)
- Powertrain Control Module (PCM)
Fig 1: Identifying Fuel System Circuits (Blackwood, Crown Victoria, Econoline, Escape, Expedition, Grand Marquis, Navigator & Pickup - Except F150 Lightning 5.4L SC)
Fig 2: Identifying Fuel System Circuits & Connector Terminals (Explorer, Explorer Sport, Explorer Sport Trac, Mountaineer, Ranger & Windstar)
NOTE:
On F150 Lightning 5.4L SC, Inertia Fuel Shutoff (IFS) switch relay may also be referred to as crash fuel shutoff relay.