How to tell if inertia switch is tripped? 5 Important Steps Before Resetting the Fuel Cutoff Switchīefore pushing the "red button" of the fuel pump shut off switch, make sure to check if there might be some other problem preventing the engine to start. The inertia switch is a security measure implemented by car manufacturers to shut off the fuel supply in case of a car crash or accident where a vehicle comes to a sudden stop. Many vehicles come with fuel pump shut off switches. This device is analog to an electric fuse, but for fuel, not electricity. What is Fuel Pump Emergency Cut Off Switch? To start with, I'm going to explain what is "fuel pump emergency shut off switch."