Fuel Pump Relay: Description and Operation

DESCRIPTION
When the ignition switch is turned to the "ON" position (before engaging starter), the Powertrain Control Module (PCM) energizes the fuel pump relay for two seconds causing the fuel pump to pressurize the fuel system. If the PCM does not receive ignition reference pulses (engine cranking or running) within two seconds, it shuts "OFF" the fuel pump relay, causing the fuel pump to stop.