TCM Speed Sensor, Calculated Speed
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
The control module receives a signal from the transmission speed sensor which is affected by a toothed pulse wheel and calculates the vehicle speed based on the signal. The speed sensor is an "active" sensor, magnet resistive with a current modulated interface. The speed is directly proportional to the frequency.
Measurement range: 0 km/h - top speed