Vehicle Speed Sensor Signal (VSS)
Range: Active/InactiveThis data indicates whether the BCM is acknowledging a vehicle speed sensor (VSS) signal at the instrument cluster via the SPI data line.
When the BCM is measuring a VSS signal message at the instrument cluster via the SPI data line, ACTIVE is displayed.
When the BCM is not measuring a VSS signal message at the instrument cluster via the SPI data line, INACTIVE is displayed.
The PCM constantly receives and converts the discrete A/C voltage signal generated by the automatic transmission output shaft speed sensor into a digital vehicle speed signal. The PCM sends this digital vehicle speed signal information to the BCM. Other modules are also involved via the class 2 serial data line and the instrument cluster via the discrete vehicle speed sensor signal (VSS) line.
The instrument cluster calculates the correct vehicle speed in order to display in km/h (mph). This is based on the vehicle speed sensor signal (VSS) input that drives the speedometer and odometer accordingly.