* Faulty Fuel Gauge Sender: This is the most probable cause. The sender unit, located in the fuel tank, measures the fuel level and sends a signal to the gauge. If the sender is malfunctioning, it'll report an empty tank even when it's full. The engine, however, might still be getting fuel.
* Fuel Pump Relay or Fuse: A blown fuse or a faulty relay prevents the fuel pump from activating. Check the fuse box (both under the hood and inside the cabin) for a blown fuse related to the fuel pump. Locate the fuel pump relay (consult your owner's manual) and try swapping it with a known good relay of the same amperage.
* Fuel Pump itself: The fuel pump could be failing. It might be weak, intermittently working, or completely dead. This is less likely if the gauge shows empty (suggesting a signal issue), but it's still a possibility. A mechanic might need to check fuel pressure.
* Wiring Issues: A break or short in the wiring between the fuel pump, the relay, and the gauge could be interfering with the signal and/or power supply. This would require careful inspection of the wiring harness.
* Inertia Switch: Some vehicles have an inertia switch that cuts power to the fuel pump in the event of a collision. This switch might have tripped, even if there wasn't an accident. Locate this switch (usually under the dash or in the engine bay) and reset it if it's tripped.
* Immobilizer System (if equipped): A malfunctioning immobilizer system could prevent the engine from starting, even if all other systems are functioning correctly. This system ties starting to a transponder key.
Troubleshooting Steps:
1. Check fuses and relays: This is the easiest and quickest first step.
2. Check the inertia switch: Simple to check and reset.
3. Listen for the fuel pump: Turn the ignition key to the "on" position (without cranking the engine). You should hear a brief humming sound from the fuel pump in the back of the vehicle. If you don't hear it, the pump or its power supply is likely the problem.
4. Have fuel pressure tested: A mechanic can easily test the fuel pressure to determine if the fuel pump is delivering fuel.
Important Note: If you're not comfortable working with automotive systems, it's best to take your Jeep to a qualified mechanic for diagnosis and repair. Working with fuel systems can be dangerous if not done properly.
