Fuel Pump

Control of the fuel pump relay is an output function of the PCM. The main relay provides operating power for the fuel pump relay. After the initial ignition ON input, the PCM provides a ground for the fuel pump control circuit. The circuit is maintained with the presence of the engine speed signal. The fuel pump relay supplies operating power to the in-tank mounted fuel pump.

All systems except V12 engine systems use a single submersed (in fuel tank) fuel pump. The V12 configuration consists of 2 redundant fuel supply systems. The pump primes the system when the ignition is switched on, and will run continuously when the engine control module senses engine RPM via the crankshaft position sensor. The pump supplies constant fuel volume to the injection system. The pickup for the pump is protected by a mesh screen.