Fuel Pump Drive Control Circuit Inspection

Fuel Pump Drive Terminal:

NOTE: The following tests should be performed only after a fuel delivery problem has been verified, no fuel pressure or low pump output.


OPERATION TEST

NOTE: Power to the fuel pump is controlled by the ECM through the MFI relay.

1. Using a scan tool, activate the fuel pump. Pump operating sound should be heard coming from fuel tank, and pulsations should be felt in fuel return line.


2. To test the pump operation, connect a 12 Volt power source to the pump test connector (located on the firewall).

3. Remove the fuel cap and listen through the fuel filler neck for the sound of the pump.

- If the pump operates during the operational test, check the wing harness for continuity between MFI relay and pump.

- If no pump sound is heard, check the ground circuit and test the MFI relay.

- If no faults are found in the ground circuit or the MFI relay, replace the fuel pump.