1. Check the Fuses and Relays:
* Locate the fuse box(es): Your Malibu likely has an underhood fuse box and one inside the cabin (often under the dash). Consult your owner's manual for the exact locations and a fuse/relay diagram.
* Identify the fuel pump fuse and relay: The owner's manual will specify which fuse and relay are responsible for the fuel pump. Look for fuses labeled "Fuel Pump," "EFI," or similar. Relays may be labeled similarly.
* Inspect the fuses: Check for blown fuses (a broken filament inside). Replace any blown fuses with fuses of the *same amperage*. If a fuse blows immediately after replacement, you have a short circuit somewhere in the system. Don't just keep replacing the fuse!
* Inspect the relay: Visually inspect the relay for any signs of damage. You can often swap relays with similar-looking ones (check your manual, some relays may be interchangeable for things like the horn, etc.) to see if the problem moves with the relay.
2. Check the Fuel Pump's Power:
* With the ignition ON (but engine OFF): You'll need a multimeter (or test light). Locate the fuel pump's wiring harness connector. The owner's manual might show its location, otherwise, you may have to trace the wires from the fuel pump back to a more easily accessible location. Be careful when working near fuel lines.
* Check for power at the connector: Turn the ignition to the "ON" position. With the multimeter set to DC voltage, check for power at the connector's positive wire. You should read a voltage close to the battery voltage (around 12V). If there's no power, the problem lies in the wiring, fuse, or relay leading to the pump. If there is power, the problem could be the pump itself.
* Check for a good ground: Test for a good ground connection at the connector using the multimeter. It should show a very low resistance (near zero) between the ground wire and a known good ground point on the chassis.
3. Check the Fuel Pump Inertia Switch:
* This safety device cuts power to the fuel pump in the event of a collision. It's usually found under the dash or in the engine compartment. It might look like a small, button-like switch, often red.
* Locate the switch and push the button to reset it. Sometimes this will solve a simple, temporary issue.
4. Check the Fuel Pump Driver Module (PDM):
* In some models, the fuel pump is controlled by a Power Distribution Module (PDM). A faulty PDM can prevent the pump from activating. This is a more advanced diagnosis and may require a professional mechanic or specialized diagnostic tools.
5. Check the Fuel Pump itself (if power is present at the connector):
* If you have power at the fuel pump connector and the ground is good but the pump still doesn't run, the fuel pump itself is likely faulty and needs replacement. This is the most expensive option. You'll likely need to drop the fuel tank to access and replace it.
Important Safety Precautions:
* Disconnect the negative battery terminal before working with any electrical components.
* Work in a well-ventilated area when working near fuel lines or the fuel tank.
* Do not smoke near fuel.
* If you are unsure about any step, consult a qualified mechanic.
By following this systematic approach, you should be able to pinpoint the cause of the problem. Remember to consult your owner's manual for specific details about your vehicle's fuse box, relay locations, and fuel system components.
