Fuel Pump: Testing and Inspection

NOTE: The fuel system wiring diagrams should be used in conjunction with the following test to correctly diagnose the problem.

1. Connect an ohmmeter and check that the fuel pump ground circuit has continuity. If there is no continuity, follow the flow from the fuel pump back to the chassis and perform necessary repairs. If there is continuity, go to step 2.
2. Turn the ignition switch to the ON position.
3. Connect a voltmeter to the DG/BK wire of the fuel pump electrical connector, and check that that there is 12 volts for approximately 2 to 3 seconds. The Auto Shutdown (ASD) relay will only operate the fuel pump for 2 to 3 seconds under a key ON engine OFF condition.
4. If there is voltage to the fuel pump, and the fuel pump still does not operate, the fuel pump is defective and needs to be replaced.
5. If there is no or low voltage at the fuel pump connector, connect a voltmeter to the DG/BK wire (terminal no. 87) of the ASD relay, and check for 12 volts. If there is voltage, repair the DG/BK wire between the ASD relay and the electrical connector of the fuel pump. If there is no voltage, test the Auto Shutdown (ASD) relay.