In-Tank Fuel Pump (MFI)
Fuel pump is located in fuel pump module. Fuel pump module is located in top of fuel tank. Fuel pump module includes a combination fuel filter/fuel pressure regulator, fuel pump reservoir, a separate in-tank fuel filter, pressure relief/rollover valve, fuel gauge sending unit, and fuel supply line. On 5.9L HD and 8.0L engines and all cab-chassis models, an auxiliary (capped) non-pressurized fuel supply fitting is located on top of fuel module.
Fuel pump is a positive displacement, immersible pump with a permanent magnet electric motor. Fuel is drawn in through a separate filter at bottom of fuel pump module and pushed through electric motor to fuel filter/fuel pressure regulator. Voltage to operate pump is supplied from fuel pump relay controlled by ASD relay. Fuel pump is not serviceable. If fuel pump is faulty, fuel pump module must be replaced.