Mazda X-5. Manual — part 62

ANTILOCK BRAKE SYSTEM

04–13–11

04–13

ABS WHEEL-SPEED SENSOR AND ABS SENSOR ROTOR CONSTRUCTION/OPERATION

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Construction
Front

• The front ABS wheel-speed sensor utilizes a

semi-conductor element that contains an active
drive circuit (MR element*). The front sensor is
installed on the front wheel hub.

• The front ABS sensor rotor utilizes a magnetic

encoder system that functions with magnetic
rubber, and is integrated into the wheel hub
component. Therefore, if there is any malfunction
of the front ABS sensor rotor, replace the wheel
hub component.

*

: A magneto-resistive force means that an exterior

magnetic field acts on the element, changing the
resistance of the element.

Caution

• When inspecting the ABS wheel-speed

sensor, do not use a tester to inspect
resistance. It is possible that the voltage
from the tester could damage the
semiconductor inside the ABS wheel-
speed sensor. Inspect using the PID data monitor of the WDS or equivalent.

Note

• Magnetic encoder: A plate that has positive and negative poles (marked out) in a continuous, alternating

line.

Rear

• The rear ABS wheel-speed sensor is installed on

the rear knuckle and the rear ABS sensor rotor is
integrated with the drive shaft. Therefore, if there
is any malfunction on the rear ABS sensor rotor,
replace the drive shaft.

FRONT ABS
SENSOR ROTOR

FRONT ABS WHEEL-
SPEED SENSOR

FRONT WHEEL HUB COMPONENT

E5U413ZS5010

REAR ABS SENSOR ROTOR

COIL

MAGNET

REAR ABS WHEEL-
SPEED SENSOR

DRIVE SHAFT

E5U413ZS5007

ANTILOCK BRAKE SYSTEM

04–13–12

Operation
Front

• As the front ABS sensor rotor rotates, the magnetic flux between the front ABS wheel-speed sensor and the

front 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 ABS HU/CM.

• For every single rotation of the ABS sensor rotor, 44 rectangular wave pulse signals are output. The CM in the

ABS HU/CM calculates the wheel speed from the periodicity of these pulses.

Rear

• 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 CM part of the ABS 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.

End Of Sie

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

C3U0413S015

V

OUTPUT VOLTAGE WAVEFORM

AT LOW SPEED

AT HIGH SPEED

E5U413ZS5008

DYNAMIC STABILITY CONTROL

04–15–1

04–15

04–15

DYNAMIC STABILITY CONTROL

DYNAMIC STABILITY CONTROL (DSC)

OUTLINE . . . . . . . . . . . . . . . . . . . . . . . . 04–15–2

DSC Operation Outline . . . . . . . . . . . . 04–15–2

DYNAMIC STABILITY CONTROL (DSC)

STRUCTURAL VIEW . . . . . . . . . . . . . . 04–15–3

DYNAMIC STABILITY CONTROL (DSC)

CONSTRUCTION . . . . . . . . . . . . . . . . . 04–15–3

DYNAMIC STABILITY CONTROL (DSC)

SYSTEM WIRING DIAGRAM . . . . . . . . 04–15–4

DSC HU/CM CONSTRUCTION. . . . . . . . 04–15–5
DSC HU PART FUNCTION . . . . . . . . . . . 04–15–5
DSC HU PART

CONSTRUCTION/OPERATION . . . . . . 04–15–5

Construction. . . . . . . . . . . . . . . . . . . . . 04–15–5
Operation . . . . . . . . . . . . . . . . . . . . . . . 04–15–7

DSC CM PART FUNCTION . . . . . . . . . . . 04–15–11

Function Table . . . . . . . . . . . . . . . . . . . 04–15–11
Block Diagram . . . . . . . . . . . . . . . . . . . 04–15–12

ABS CONTROL FUNCTION . . . . . . . . . . 04–15–12
EBD CONTROL FUNCTION . . . . . . . . . . 04–15–12
TCS CONTROL OUTLINE . . . . . . . . . . . 04–15–13

Features . . . . . . . . . . . . . . . . . . . . . . . . 04–15–13
Block Diagram . . . . . . . . . . . . . . . . . . . 04–15–13

TCS CONTROL OPERATION . . . . . . . . . 04–15–13
DSC CONTROL OUTLINE . . . . . . . . . . . 04–15–14

Vehicle Condition Determination . . . . . 04–15–14
Oversteer Tendency Determination . . . 04–15–14
Understeer Tendency

Determination. . . . . . . . . . . . . . . . . . . 04–15–14

DSC CONTROL OPERATION. . . . . . . . . 04–15–15

Oversteer Tendency Suppression . . . . . 04–15–15
Understeer Tendency Suppression . . . . 04–15–15

CONTROLLER AREA NETWORK (CAN)

OUTLINE . . . . . . . . . . . . . . . . . . . . . . . . 04–15–16

Data sent. . . . . . . . . . . . . . . . . . . . . . . . 04–15–16
Data received . . . . . . . . . . . . . . . . . . . . 04–15–16

ABS WHEEL-SPEED SENSOR

FUNCTION . . . . . . . . . . . . . . . . . . . . . . . 04–15–16

ABS WHEEL-SPEED SENSOR

CONSTRUCTION/OPERATION . . . . . . . 04–15–16

COMBINED SENSOR FUNCTION . . . . . . 04–15–16
COMBINED SENSOR

CONSTRUCTION/OPERATION . . . . . . . 04–15–16

BRAKE FLUID PRESSURE SENSOR

FUNCTION . . . . . . . . . . . . . . . . . . . . . . . 04–15–17

BRAKE FLUID PRESSURE SENSOR

CONSTRUCTION . . . . . . . . . . . . . . . . . . 04–15–17

STEERING ANGLE SENSOR

FUNCTION . . . . . . . . . . . . . . . . . . . . . . . 04–15–17

STEERING ANGLE SENSOR

CONSTRUCTION . . . . . . . . . . . . . . . . . . 04–15–17

DSC INDICATOR LIGHT FUNCTION. . . . 04–15–17
DSC INDICATOR LIGHT

OPERATION . . . . . . . . . . . . . . . . . . . . . . 04–15–18

DSC Indicator Light Operation . . . . . . . 04–15–18

DSC OFF SWITCH, DSC OFF LIGHT

FUNCTION . . . . . . . . . . . . . . . . . . . . . . . 04–15–18

DSC OFF SWITCH, DSC OFF LIGHT

OPERATION . . . . . . . . . . . . . . . . . . . . . . 04–15–18

End of Toc

DYNAMIC STABILITY CONTROL

04–15–2

DYNAMIC STABILITY CONTROL (DSC) OUTLINE

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• The DSC HU/CM, integrating both the hydraulic unit (HU) and control module (CM), has been adopted,

resulting in a size and weight reduction.

• A combined sensor, integrating both the yaw rate sensor and lateral-G sensor, has been adopted, improving

serviceability.

• The controller area network (CAN) system has been adopted for the steering angle sensor, improving

serviceability and reliability.

• An enhanced malfunction diagnosis system, used with the WDS, has been adopted, improving serviceability.

DSC Operation Outline

• The ABS prevents wheel lock-up during braking. The TCS detects drive wheel spin due to the accelerator pedal

being pressed too hard or similar causes and controls engine speed to suppress wheel spin. With these
systems, safety is assured when driving or stopping.

• Additionally, sudden changes in vehicle attitude, due to evasive steering or road conditions, are controlled by

the DSC. The DSC suppresses vehicle sideslip when driving due to vehicle spin (oversteer) or drift-out
(understeer) by controlling braking and engine speed. At this time, the DSC indicator light illuminates to alert
the driver that the DSC is operating due to a dangerous situation. As a result, the driver can calmly react and is
provided leeway for the next maneuver, resulting in safe driving conditions.

• In this way the combination of DSC + ABS + TCS ensures driving, stopping and turning safety in all aspects.

Results Of DSC Operation

Caution

• While the DSC is a steering safety system, it does not improve normal steering function.

Therefore, always drive carefully, even if the vehicle has DSC, and do not overestimate the DSC
capability.

• The DSC and ABS will not operate normally under the following conditions:

— With tires that are not of the specified size, manufacturer or tread pattern, or not inflated

according to specification

— With tires that have significant comparative wear variation

— With tire chains

WITHOUT DSC

WITH DSC

DRIFT OUT
(UNDERSTEER)

DRIFT OUT (UNDERSTEER) SUPPRESSION

WITH DSC

WITHOUT DSC

VEHICLE SPIN
(OVERSTEER)

VEHICLE SPIN (OVERSTEER) SUPPRESSION

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