Fuel Pump Relay: Description and Operation
PURPOSEProvides the powertrain control module engine (PCME) with the ability to control fuel pump operation based on PCME inputs.
OPERATION
The relay gets battery power from the main relay when the ignition is turned ON. It is energized when the PCME completes the circuit to ground through the relay coil. The relay in turn supplies power from the main relay to the electric fuel pump. As a safety feature, the relay is only energized when the engine is running or being cranked by the starter motor. If the engine dies (no engine speed signal), the PCME turns the relay OFF.