Diagnostic Aids
Perform this test when directed by QUICK TEST or if directed by other test procedures. This test is used to diagnose:
- Chassis Components
- Engine Vacuum Systems
- Fuel Pressure
- Fuel Filter
- Fuel Return
- Fuel Supply
- Fuel Injector
Fuel System Identification
- Electronic Returnless Fuel System
Electronic Returnless Fuel System (ERFS) does not return fuel to fuel tank by means of a fuel return line. Vehicle does not incorporate a fuel pressure regulator. Fuel pressure is controlled by continuously varying fuel pump speed through Fuel Pump Driver Module (FPDM). - Mechanical Returnless Fuel System
Mechanical Returnless Fuel System (MRFS) does not return fuel to fuel tank by means of a fuel return line. Excess fuel is returned by fuel pressure regulator mounted on fuel pump module located in fuel tank. - Returnable System
Fuel is returned to fuel tank by means of return line from fuel rail.
FUEL SYSTEM IDENTIFICATION
| Application | Fuel System |
|---|---|
| Continental, Cougar, Escape, Escort, Focus, LS, Mustang, Sable, Taurus & Thunderbird | Electronic Returnless |
| Econoline 5.4L (Gasoline), Excursion 5.4L, Expedition 5.4L, Explorer, Explorer Sport, Explorer Sport Trac, Mountaineer, Pickup 5.4L (Gasoline), Ranger | Mechanical Returnless |
| All Others | Returnable |
WARNING:
Always refer to safety procedures to reduce possibilty of injury. See FUEL SYSTEM SAFETY PRECAUTIONS
.