Passport 4WD V6-3.2L SOHC (6VD1) (1994)
Vehicle Speed Sensor: Description and Operation
Circuit Description
The vehicle speed sensor generates a signal which indicates the vehicle speed to the speedometer. The speedometer consists of a vehicle speed sensor, an
ammeter (needle movement), stepper motor (odometer), and a driving circuit (printed circuit board).
The vehicle speed sensor is mounted to the transmission. The transmission pinion shaft rotates and generates four pulses per one rotation. The rate at
which the pulses are generated indicates the vehicle speed. The vehicle speed sensor (in the speedometer) uses the pulses to control needle movement,
and sends vehicle speed information to the ECM and the cruise control unit. The speedometer sends 4096 pulses per mile; the frequency of these pulses
indicates the vehicle speed.