Inertia Fuel Shutoff Switch: Description and Operation
ENGINE CONTROL COMPONENTSInertia Fuel Shut-off (IFS) Switch
The IFS switch is used in conjunction with the electric fuel pump. The purpose of the IFS switch is to shut off the fuel pump if a collision occurs. It consists of an inverted pendulum mass that is retained in a conical cone via 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:
