Fuel Pump Control

When the ignition switch is turned on, the PCM grounds PGM-FI main relay 2 which feeds current to the fuel pump control module. The PCM sends a signal to the fuel pump control module to operate the fuel pump for 2 seconds to pressurize the fuel system. With the engine running, the fuel pump speed is controlled in four levels by the fuel pump control module. The PCM decides the fuel pump speed by the calculation of the injector activation time and engine speed and sends a operation command signal to the fuel pump control module. This operation made possible to decrease fuel pump noise at low engine speed.