Electronic Returnless Fuel System
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The hybrid vehicle uses the electronic returnless fuel system. The system consists of a fuel tank with reservoir, the fuel pump, the fuel filter, the fuel supply line, the fuel rail pressure temperature (FRPT) sensor, the fuel rail, the fuel pump driver module (FPDM), and the fuel injectors. Operation of the system is as follows:
- The fuel delivery system is enabled during crank or running mode once the PCM receives a crankshaft position (CKP) sensor signal.
- The fuel pump logic is defined in the fuel system control strategy and is executed by the PCM.
- The PCM commands a duty cycle to the FPDM.
- The FPDM modulates the voltage to the fuel pump (FP) required to achieve the proper fuel pressure. Voltage for the fuel pump is supplied by the FPDM. For additional information on FPDM operation, refer to FUEL PUMP (FP) and FUEL PUMP MONITOR (FPM) .
- The FRPT sensor provides the PCM with the current fuel rail pressure and temperature. The PCM uses this information to vary the duty cycle output to the FPDM to compensate for varying loads.
- The fuel injector is a solenoid operated valve that meters the fuel flow to each combustion cylinder. The fuel injector is opened and closed a constant number of times per crankshaft revolution. The amount of fuel is controlled by the length of time the fuel injector is held open. The injector is normally closed and is operated by VPWR from the power relay. The ground signal is controlled by the PCM.
- There are 3 filtering or screening devices in the fuel delivery system. The intake sock is a fine, nylon mesh screen mounted on the intake side of the fuel pump. There is a fuel filter screen located at the fuel rail side of the fuel injector. The fuel filter assembly is located between the fuel pump and the fuel rail.
- The fuel pump (FP) module is a device that contains the fuel pump and the fuel sender assembly. The fuel pump is located inside the reservoir and supplies fuel through the fuel pump module manifold to the engine and the fuel pump module jet pump.
- The front inertia fuel shut-off (IFS) switch is used to de-energize the fuel delivery secondary circuit in the event of a collision. The IFS switch is a safety device that should only be reset after a thorough inspection of the vehicle following a collision.