The Transmission Range sensor encompasses all functions of a Park/Neutral Position switch, although the term PNP switch remains commonly used among various manufacturers. This sensor prevents the engine from starting in any gear position other than PARK or NEUTRAL, while also monitoring the selector lever position and sending a signal to the Transmission Control Module, which utilizes this information to determine the appropriate pressure for the electronic pressure control system of the transmission. Housed inside the transmission at the valve body, any diagnostic trouble codes indicating an issue with this component or related components suggest that repairs should be conducted at a dealership service department or a qualified transmission repair shop. If the engine starts when the shift lever is in any position other than Park or Neutral, it may be necessary to consider shift cable adjustment before seeking professional repair services.