POST UPDATED IN September, 2020
For its acronym in English Vehicle Speed Sensor, the VSS sensor is a magnetic sensor that is located in the transaxle of the speedometer cable. It is responsible for informing the Engine Control Module (ECM) of the speed of the vehicle, and thus controls the speedometer and odometer, also controls the adjustment of the TCC (Torque Converter Clutch) and automatic transmissions. It has a magnet, which rotates and generates a sine wave AC (Alternating current) directly and in proportion to the speed of the vehicle. At each turn of the shaft 8 cycles are generated and the resistance should be between 190 and 240 ohms.
Its essential function is to send a signal regarding the evolution of the wheels in relation to the car. The VSS sensor sends an AC (Alternating Current) signal to the Engine Control module (ECM) and this interprets it as the vehicle speed. When the speed of the vehicle increases, the frequency and voltage do the same. From there, the ECM (Motor Control Module) converts that voltage into Km / h and is used for its calculations.