Wheel Sensor; Wheel Speed And Modulator Control - Honda CR-V 1997 Service Manual

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 ASS control unit detects
the wheel sensor signal freq uency and thereby detects the wheel speed.
GEAR PUlSER
o
WHEEL SENSOR
at
HIGH SPEED
at lOW SPEED
Wheel Speed and Modulator Control
SPEED
VEHICLE SPEED
REFERENCE VEHICLE SPEED
\ \ ,
: \
WHEEL SPEED
~--C:'='
TIME
PRESSUREI~J~
A. , '
~. ' . = ====~...L--L~======:::j: : ll--~ :
:'t===
li.J
~ . ~
OUTLET
t
VALVE ON
OFF
L-_ ...LO-l--_ _ ---' - ' - ----L..JOL- ' _ _ _ _
'--:----'-0---'--_
VALVE ON . . . . . .
INLET
t
OFF
_~------,--,-I
D. . u . . . I _ _ _ _ --' - 1 L. . I . . . . O . L . . . . . . . I _ _
MOTOR
ON
t
OFF
~_-L
______________________________________________ _
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,
19-31