Mazda Training manual — part 101

Dynamic Driving Safety Systems

DSC

Diagnostics

•

The HU/CM can be checked by:

–

Reading out DTCs

–

Checking voltage signals

–

Monitoring / Activating the corresponding PIDs (see below)

PID

Definition Unit/Condition

BOO_ABS

Brake switch

ON/OFF

CCNTABS

Number of detected DTCs

-

ESP_VOLT

IVD/DSC sensor supply voltage

V

LATACCEL#

Initialisation start-up for combined sensor

True / False

LAT_ACCL

Lateral G-force from combined sensor

G

LF_INLET#

LF ABS pressure inlet solenoid valve

ON/OFF

LF_OUTLET#

LF ABS pressure outlet solenoid valve

ON/OFF

LF_TC_PRV#

LF stability control solenoid valve

ON/OFF

LF_TC_SWV#

LF traction control solenoid valve

ON/OFF

LF_WSPD

LF ABS wheel-speed sensor input

km/h, mph

LR_INLET#

LR ABS pressure inlet solenoid valve

ON/OFF

LR_OUTLET#

LR ABS pressure outlet solenoid valve

ON/OFF

LR_WSPD

LR ABS wheel-speed senor input

km/h, mph

MCYL_S_CAL#

Initialisation start-up for brake fluid pressure sensor

True / False

MPREDTDR

Brake fluid pressure

kPa, psi, bar

PMP_MOTOR#

ABS motor

ON/OFF

RF_INLET#

RF ABS pressure inlet solenoid valve

ON/OFF

RF_OUTLET#

RF ABS pressure outlet solenoid valve

ON/OFF

RF_TC_PRV#

RF stability control solenoid valve

ON/OFF

RF_TC_SWV#

RF traction control solenoid valve

ON/OFF

RR_INLET#

RR ABS pressure inlet solenoid valve

ON/OFF

RR_OUTLET#

RR ABS pressure outlet solenoid valve

ON/OFF

RF_WSPD

RF ABS wheel-speed sensor input

km/h, mph

RR_WSPD

RR ABS wheel-speed sensor input

km/h, mph

SWA_POS

Steering angle sensor

°

TCYC_FS

DSC stand by

ON/OFF

TCYC_SW

DSC OFF switch

Pressed/Not pressed

YAW_RATE

Yaw rate value from combined sensor

°/s

L2003_T02019

Mazda3

Curriculum Training

02-63

DSC

Dynamic Driving Safety Systems

Combined Sensor

•

On current Mazda vehicles, the combined sensor is located either below the passenger’s
seat, or below the centre console (MX-5 and Mazda6). As the name implies, it
incorporates a combination of at least two sensors, that measure yaw rate and
transverse acceleration.

•

The combined sensor is either hardwired or connected via a separate CAN to the DSC
HU/CM.

•

The sensors themselves are a special kind of accelerometer built into a microchip (or a
similar type). They operate both mechanically and/or electronically and are used to
detect yaw rate and lateral G force acting on the vehicle. The combined sensor transmits
detected forces either via CAN to the DSC CM or, if hardwired, as a corresponding
voltage signal. These signals are used to assist the DSC CM to distinguish between
stable and unstable driving conditions.

NOTE: The combined sensor is highly sensitive against impacts. Therefore, the sensor has

to be replaced after it fell down.

NOTE: The mounting bolts and nuts of the combined sensor must always be tightened to the

specified torque in the compulsory sequence (refer to W/M). Ensure that the sensor
is correctly aligned, otherwise the measurement results for yaw rate and transverse
acceleration could be affected, causing a malfunction of the DSC.

L2003_02037

1 Combined

sensor

connector

4 Bracket

2 Nut

5 Bolt

3 Combined

sensor

02-64 Curriculum

Training

Dynamic Driving Safety Systems

DSC

Diagnostics

•

The combined sensor can be checked by:

–

Reading out DTCs

–

Checking voltage signals

–

Monitoring / Activating the corresponding PIDs (see below)

PID

Definition Unit/Condition

LATACCEL#

Initalisation start-up for combined sensor

ON/OFF

LAT_ACCL

Lateral G-force from combined sensor

G

YAW_RATE

Yaw rate value from combined sensor

°/s

L2003_T02025

Replacement

•

If a combined sensor needs to be replaced, the new sensor must be initialised with the
aid of the M-MDS (refer to W/M).

Steering Angle Sensor

•

The steering angle sensor is attached to the steering column, and is located between the
clock spring and the combination switch. It is either integrated into the combination
switch or is a separate component.

•

Mazda vehicles are equipped with different types of combination sensors. They always
transmit a steering wheel turn signal allowing the DSC CM to detect any rotation
(degrees and direction) and the neutral position of the steering wheel. The steering angle
sensor is either hardwired or connected via HS-CAN to the DSC HU/CM. Up to three
different voltage signals can be transmitted from a hardwired steering angle sensor,
depending on the model.

•

Signal generation is done either with the aid of a photoelectric barrier, hall element type
sensors, or GMR (Giant Magneto Resistor) type sensors. The operation of the
photoelectric barrier type is explained below.

•

The steering angle sensor on the Mazda3 (BK) is a separate unit. It features a sensor
unit with a photo transistor, positioned opposite a LED straddling a slitted disc, that
rotates together with the steering wheel.

•

As the disc rotates, the LED light, received by the photo transistor, varies due to the slits
on the disc. The photo transistor outputs an ON signal when it receives light and an OFF
signal when the light is blocked. The DSC HU/CM calculates the steering angle and the
turning speed of the steering wheel based on the phase difference between sensor A
and B outputs.

Curriculum Training

02-65

DSC

Dynamic Driving Safety Systems

L2003_02038

1

Vehicle front

5

Steering angle signal A

2

Disc

6

Detection circuit (inside DSC HU/CM)

3 Sensor

unit

7 Slit

4

Steering angle signal B

02-66 Curriculum

Training