Circuit Description

With the ignition test ON (II) or START (III), battery voltage is supplied through fuse 24 and the BLK/YEL wire to the Vehicle Speed Sensor (VSS). The sensor is grounded by the BLK wire to G101. The speedometer and the other control units in the circuit supply about 5 volts to the YEL/WHT wire. The vehicle speed sensor (VSS) intermittently grounds the YEL/WHT wire which generates a pulsed signal in it. The number of pulses per minute increases/decreases with the speed of car.