Inertia Fuel Shutoff (Ifs) Switch
The IFS switch is used in conjunction with the electric fuel pump. The IFS switch shuts off the fuel pump if a collision occurs. It consists of an inverted pendulum mass that is retained in a conical cone through a set of linear springs. When a sharp impact occurs, the pendulum shifts out of the conical cone, opens the circuit and shuts off the electric fuel pump. Once the switch is open, it must be manually reset before restarting the vehicle.
Typical IFS Switch