Fuel Pump Control Unit: Description and Operation

DESCRIPTION
This engine utilizes a two speed fuel pump control module. The fuel pump control module is located on the left-wheel house flange in the trunk.

OPERATION
The fuel pump control module can vary the fuel pump output depending on the reference pulses received by the PCM. When the ignition is first turned On, the PCM energizes the fuel pump relay which applies power to the fuel pump control module. Based on engine fuel demand, the PCM sends a signal to the fuel pump control module to change the fuel pump control module voltage output. The fuel pump will then pressurize the fuel system. The fuel pump relay will remain On as long as the engine is running or cranking and the PCM is receiving reference pulses. If no reference pulses are present the PCM de-energizes the fuel pump relay within two seconds after the ignition is turned On, or the engine is stopped.

Refer to Fuel Pump Relay Circuit Diagnosis for further description and diagnosis of the fuel pump electrical circuit.