Fuel Pump Control
PURPOSE^ When the ignition switch is initially turned on, the Engine Control Module (ECM) supplies ground to the Programmed Fuel Injection (PGM-FI) main relay that supplies current to the fuel pump for two seconds to pressurize the fuel system.
^ When the engine is running, the ECM supplies ground to the PGM-FI main relay that supplies current to the fuel pump.
^ When the engine is not running and the ignition is on, the ECM cuts ground to the PGM-FI main relay which cuts current to the fuel pump.