Circuit/System Description

The engine control module (ECM) provides ignition voltage to the fuel pump power control module whenever the engine is cranking or running. The control module enables the fuel pump power control module as long as the engine is cranking or running, and ignition system reference pulses are received. While this enable voltage is being received, the fuel pump power control module supplies a varying voltage to the in-tank fuel pump module in order to maintain the desired fuel line pressure.