Vehicle Speed Sensor: Description and Operation

^ The Vehicle Speed Sensor, located in the speedometer assembly, is an "ON/OFF" switch operated by speedometer cable rotation.
^ Switch cycles four times per cable revolution. ECU monitors this signal and calculates vehicle speed based on frequency of "ON/OFF" cycles.
^ Vehicle speed information is used in ECU calculations for various outputs, including automatic transmission control.
^ Rather than use a separate EC-AT control unit, this vehicle incorporates electronic transmission controls within the main ECU.