3.2TL TYPE S V6-3.2L SOHC (2002)
Wheel Speed Sensor: Description and Operation
VSA
Wheel Sensor
The wheel sensors are the magnetic contactless type. As the gear pulser teeth rotate past the wheel sensor's magnetic coil, AC current is generated. The
AC frequency changes in accordance with the wheel speed. The VSA control unit detects the wheel sensor signal frequency and thereby detects the
wheel speed.
Wheel Speed and Modulator Control (ABS)
When the wheel speed drops sharply below the vehicle speed, the outlet valve opens momentarily to reduce the caliper fluid pressure. The pump
motor starts at this time. As the wheel speed is restored, the inlet valve opens momentarily to increase the caliper fluid pressure.
Steering Angle Sensor
The steering angle sensor detects the steering wheel turning angle. A disk with evenly spaced slits is positioned between the facing parts of a Light
Emitting Part (LED), and a light receiving part (photo transistor). As the disk rotates, it interrupts the light from the LED. The light which passes
through a slit is converted into the electric current by the photo transistor, and the waveform of this electric current is converted by the comparator into
a square wave output of the disk's rotation.
The output signal is a 2-phase output (A-phase and B-phase), and the steering wheel turning angle and the turning direction are calculated by the VSA
