Neutral Safety Switch

A neutral safety switch is a mechanism that prevents the car engine from turning on when the transmission is in gear. It allows the engine to start only if the gearshift is in the 'park' or 'neutral' position. Without this switch, the engine would start whenever the key is turned in the ignition, and if the transmission was left in gear, this could make the vehicle shoot out from a stationary position, possibly injuring the occupant and/or whoever is near the car. In some models, the neutral safety switch is also responsible for turning on the back-up lights while reversing.