Vehicle Speed Sensor (VSS)

VSS is a Permanent Magnet (PM) generator mounted in transmission or transfer case. The VSS sends a pulsing signal to the PCM/VCM or Digital Ratio Adapter Controller (DRAC), which passes the signal on to the PCM/VCM. The PCM/VCM then converts this signal into miles per hour by monitoring the time interval between pulses. PCM/VCM uses this sensor input in controlling Torque Converter Clutch (TCC) engagement, shift speed, etc.