How to Troubleshoot the Fuel Pump in a 2002 Nissan Sentra

The car won't start, or it acts like it is trying to stall when being driven. Chances are, you've replaced the fuel filter, given the engine a tune-up, and checked the starter, alternator and battery. Maybe it's the fuel pump. Fuel pumps are expensive, so don't buy one unless it is absolutely necessary. Take the time to troubleshoot the system. After all, spending money on a fuel pump not knowing for sure that the fuel pump is bad is not only a waste of money but a waste of time as well.

Things You'll Need

  • Volt meter
  • Electrical tape
  • Remove the gas cap.

  • Turn the ignition switch to the On position, but do not start the vehicle. The fuel pump makes a whirring noise for a few seconds when it is working. Have someone assist with this step if necessary.

  • Check the fuel pump fuse if no noise is heard. (The fuel pump fuse is located on the lower dash panel near the hood release panel. It is the number 17 fuse.)

  • Replace the fuse if it is blown. (A break or possible burn is noticeable.)

  • Follow the wiring from the fuse panel to the fuel pump if the fuse blows again. Look for open, loose, cut or burnt wiring and replace the harness if necessary.

  • Check the fuel pump relay if the fuse is not blown. The relay is mounted in the relay box under the hood. Connect a ground to terminal 1 and battery voltage terminal 2. You'll hear a click if there is voltage.

  • Remove the fuel pump relays and check for battery voltage to the fuel pump, using a voltmeter.

  • Trace the wiring from the circuit for open, cut, loose or burnt wiring if no voltage is present. If voltage is present and the relays are good, replace the relays.

  • Remove the rear seat. Use the voltmeter to check for power at the fuel pump harness connector. If no power is present, trace the wiring from the relay circuit to the fuel pump harness. Check for damaged wires.

  • Replace the fuel pump if power is reaching the fuel pump and the relays are good.