Switch, Inertia: Operation

The inertia switch is intended to disable the fuel pump after an heavy impact. A small loose weight (mass) is trapped within a spring-loaded cage. A shock in any direction will cause movement of the mass relative to the cage, and if sufficiently shocked. The cage will spring open, disconnecting the signal wire to the fuel pump relay. The switch is reset by pressing the cage closed through the flexible top cover, retrapping the mass.

When the switch in open. The PCM signal is redirected to the BCM. The BCM activates the light on the dash advising that the inertia switch has been initialized.