Inertia Fuel Shutoff Switch: Description and Operation

Inertia Fuel Shutoff Switch:

CAUTION: Do not reset the Inertia Fuel Shutoff switch (IFS switch) until the entire fuel system has been inspected for leaks.

An IFS switch is connected in series with the fuel pump circuit and will stop fuel pump operation in the event of a major collision or vehicle rollover.

Typical Inertia Fuel Shutoff (IFS) Switch:

In the event of a collision, the electric contacts in the IFS switch open. With the IFS switch open, the fuel delivery circuit is opened, disabling the fuel system. The engine may continue to run for several seconds after the IFS switch has opened, due to fuel remaining in the fuel supply line. Once the fuel in the supply line has been used, the engine will stall.

The reset button must be pushed to reset the IFS switch once it has been triggered.