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 ABS control unit detects
the wheel sensor signal frequency and thereby detects the wheel speed
at LOW SPEED
wheel Sp€od and Modulatot Control
VEHICLE SPEED
VEHICLE SPEED
WHEEL SPEED
PRESSU
OUTLETVALVE ON
OFF
INLETVALVE ON
OFF
MOTOR
ON
OFF
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 caliDer fluid oressure.
F
GEAR PULSER
19-31
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