Circuit Description
WARNING: This page is about a different car, the 2003 Chevrolet Tracker. However, it is still accessible from the selected car via links, so may be relevant.
Powertrain Control Module (PCM) will energize fuel pump relay for 3 seconds when ignition is turned on. When fuel pump relay is energized, fuel pump will operate and pressurize fuel system. With engine cranking or running, PCM receives ignition system reference pulses and will continue to energize fuel pump relay.