How to Troubleshoot a Fuel Pump in Vehicles

by Contributing WriterUpdated June 12, 2017

The fuel pump on a Vehicles Chevy Vehicles is located in the fuel tank. It is mounted in tandem with the fuel level sending unit. The computer (the engine control module or ECM) actuates the relay Vehicles two seconds unless it senses an engine start and increase in rpm. If it does not sense an engine start and increase in rpm, the computer breaks the connection after two seconds, thus shutting the fuel pump off. This is a safety precaution to prevent the fuel pump from pumping fuel into an engine that is off or not working properly.

Under The Hood:

 How to Troubleshoot a Fuel Pump in a 1999 Dodge Durango

Check the fuel pump fuse under the dash. Open the dash fuse panel box and locate the fuse for the fuel pump. Place the teeth of the supplied fuse puller over the end of the fuse and pull the fuse straight out. Inspect the fuse to see if the fuse has popped. If the fuse is fine, then put the fuse back into place.

Turn your Durango's ignition to the "II" position. Do not crank the engine.

Listen for a slight humming sound. When you turn the key in the ignition to the "II" position, the fuel pump relay will energize and cause a faint hum. The sound should be coming from the rear of the Durango, where the fuel pump is located.

Attempt to start the Durango. If you did not hear the relay energize, you should not be able to start your vehicle. If this is the case, you must replace your fuel pump and relay.

Items you will need

  • Small flat blade screwdriver

  • Clean rag

 How to Troubleshoot a Fuel Pump on a 1994 Camaro

Check the fuel pump fuse in the fuse/relay box by taking the cover off and examining the diagram under the cover. Locate the fuse and the relay for the fuel pump. Check and replace the fuse if it is blown and try to start the vehicle. If the fuse was blown and replaced but the Camaro still will not start, proceed to the next step.

Remove the air duct between the air cleaner element and the throttle body, using a screwdriver to loosen the clamps. Open the throttle body by pushing the throttle linkage on the side of the throttle body. Spray a one-second squirt of carburetor cleaner into the throttle body. Close the valve and attempt to start the vehicle. If it starts for a few seconds, the fuel pump or the fuel pump relay is bad.

Locate the fuel pump relay and pull it out. Notice that the relay has four legs. There are four female terminals in the relay box. Use the voltmeter, with its black lead connected to a good ground and the red lead as a probe. There should be one terminal with battery power with the key off when probing the terminals. Employ a helper for this next test. Have a helper cycle the ignition key on and off every few seconds while you probe the remaining three terminals for power. The circuit is good if there is power present (as shown on the voltmeter) when cycling the key.

Connect the two jumper wires to the battery terminals--one on the positive terminal and one on the negative terminal. Make sure to keep these wires from touching each other. Connect the red positive jumper to a leg of the relay, and touch the opposite leg with the black ground wire. The relay should click audibly if it works. If you do not hear a click, switch to the next two terminal legs. If you do not hear a click, replace the relay. If the fuel pump still malfunctions, replace the fuel pump.

Items you will need

  • Volt meter

  • Small pocket screwdriver

  • 2 short jumper wires with alligator clips

  • Can of carburetor cleaner

 How to Troubleshoot the Fuel Pump on a 2003 Malibu

Check the fuse block for a blown fuse. There are three fuse blocks in the Chevrolet Malibu. The fuel pump fuse is located in the trunk. It's accessed through the trunk panel on the driver's side. The fuel pump fuse is in Location 25. That's the bottom right-most fuse.

Remove the existing fuse with the included tweezer tool. Look at the wire inside the fuse. If it's broken, the fuse needs replacing. Replace it by inserting a new fuse in the same location. Be sure to match color and amperage. Check that the fuel pump operates.

Replace the relay if the fuel pump still doesn't work. The relay is in the same block. It's the bottom right-most relay, right next to the fuel pump fuse. Pull the relay out from the harness and snap a new one in place. Try the fuel pump again.

Items you will need

  • Spare fuses

  • Spare relay

 How to Troubleshoot the Fuel Pump in a 2002 Nissan Sentra

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.

Items you will need

  • Volt meter

  • Electrical tape

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