The design of the fuel pump inertia switch causes it to turn off the fuel pump if a vehicle is involved in an accident. However, in certain incidents such as a blown tire or hitting a pothole in the road, the switch has the potential to trip. If an automobile is not operating correctly, the manufacturer recommends that the switch be checked.
Ford installs inertia switches in all its fuel-injected vehicles. It prevents potentially dangerous fuel leaks if an accident severs a fuel line. In passenger cars, the switch is typically located in the trunk and is identifiable by the red button on its top. A sudden stop or change in direction activates the switch. When it is in the open position, this button raises. This stops power to the electric fuel pump. If the vehicle starts, it only runs a few seconds before the engine dies. Further attempts to start the vehicle are usually unsuccessful. Resetting the switch restores power to the fuel pump. To reset the switch, car owners should push the red button in toward the housing of the switch. Once the power is restored to the switch, the car receives the fuel it needs to start and operate again.