Mazda 2007 CX-9, Service Highlights

Page: 216 / 614

DYNAMIC STABILITY CONTROL/ROLL STABILITY CONTROL
04-18–28
Operation
Front and rear (AWD)
•
As the ABS sensor rotor rotates, magnetic flux
formed from the permanent magnet varies and
alternating current is formed with an
electromagnetic conductor. Using this alternating
current, rotation speed is expressed as a varying
proportional cycle and from detection of this cycle
the control module (CM) part of the dynamic
stability control (DSC)/roll stability control (RSC)
hydraulic unit (HU)/CM can then detect the wheel
rotation speed. While the structures of the front
and rear ABS wheel-speed sensor differ, the
operation is the same.
Rear (2WD)
•
As the rear ABS sensor rotor rotates, the magnetic flux between the rear ABS wheel-speed sensor and the rear
ABS sensor rotor change periodically. This periodic change is in proportion to the rotation speed.
•
The semiconductor element in the wheel speed sensor detects the change in magnetic flux, and the active
drive circuit converts it to a rectangular wave signal for the current, which is transmitted to the DSC/RSC HU/
CM.
•
For every single rotation of the ABS sensor rotor, 44 rectangular wave pulse signals are output. The CM in the
DSC/RSC HU/CM calculates the wheel speed from the periodicity of these pulses.
End Of Sie
NG: COMBINED SENSOR
V
OUTPUT VOLTAGE WAVEFORM
AT LOW SPEED
AT HIGH SPEED
ac9uun00000398
DETECTION PRINCIPLE
ABS WHEEL-SPEED SENSOR
ACTIVE DRIVE CIRCUIT
SEMICONDUCTOR
ELEMENT
MAGNETIC RUBBER
(MAGNETIC ENCODER)
ABS SENSOR ROTOR
OUTPUT WAVE PATTERN
ACTIVE DRIVE CIRCUIT
HI
LO
RECTANGULAR
WAVE SIGNAL
SEMICONDUCTOR
ELEMENT
ac9uun00000399
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