Fuel System

Fuel System

The Mechanical Returnless Fuel System (MRFS) consists of:

- a fuel rail.

- a saddle-type fuel tank on All-Wheel Drive (AWD) vehicles or an L-shaped fuel tank on Front Wheel Drive (FWD) vehicles.

- fuel, vapor and brake tubes in an integrated bundle assembly.

- a fuel tank filler pipe assembly, which cannot be modified in any way.

- Easy Fuel(TM) (capless) fuel tank filler pipe assembly.

- an Fuel Pump Control Module (FPCM).

- a Fuel Pump (FP) module containing:
- the electric FP (Fuel Pump), which provides pressurized fuel to the fuel rail.

- the fuel level sensor.

- a check valve, which maintains system pressure after the FP (Fuel Pump) is shut off.

- a pressure relief valve for overpressure protection in the event of restricted fuel flow.

- an in-tank fuel filter providing filtration to protect the fuel injectors from foreign material.


All vehicles have a fuel level sensor on the FP (Fuel Pump) module. AWD (All-Wheel Drive) vehicles have an additional fuel level sensor located in the RH side of the fuel tank.

The engines are equipped with sequential MFI (Multi-Port Fuel Injection) injection.

The fuel pressure is regulated to a constant pressure by a fuel pressure regulator.

Fuel System Shutoff Feature

In the event of a moderate to severe collision, the vehicle is equipped with a Fuel Pump (FP) shut-off feature that is initiated by the event notification signal.

The event notification signal is a signal provided by the Restraints Control Module (RCM) to the Fuel Pump Control Module (FPCM). The FPCM (Fuel Pump Control Module) will then shut-off power to the FP (Fuel Pump) module. The RCM (Restraints Control Module) will also send a fuel shut-off signal to the Powertrain Control Module (PCM). The PCM (Powertrain Control Module) will then send a signal to the FPCM (Fuel Pump Control Module) to shut-off the FP (Fuel Pump) module.

Should the vehicle shut-off after a collision due to this feature, the vehicle may be restarted by first turning the ignition switch to the OFF position and then turn the ignition switch to the ON position. In some instances the vehicle may not start the first time and may take one additional key cycle.