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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 372 (Engine Controls - System & Component Testing - 3.4L) >> Fuel Systems >> Fuel Pump Electrical Circuit Diagnosis (ALERO & Grand Am) >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

When the ignition switch is turned to RUN position, the Powertrain Control Module (PCM) enables the fuel pump relay which powers the fuel pump ON. The fuel pump remains ON as long as the engine is cranking or running and the PCM receives ignition reference pulses. If there are no ignition reference pulses, the PCM shuts the fuel pump OFF within 2 seconds after the ignition was switched to the RUN position or if the engine stops.