Mazda 6. Manual - part 243

P–28

ABS/TCS 

ABS (ABS/TCS) HU/CM REMOVAL/INSTALLATION

A6E692143700W01

Caution

• When replacing the ABS (ABS/TCS) HU/CM, configuration procedure must be done before 

removing the ABS (ABS/TCS) HU/CM. If configuration is not completed before removing the ABS 
(ABS/TCS) HU/CM, TCS will not work properly (with TCS model).

• Do not drop the ABS (ABS/TCS) HU/CM. Replace it if it is subjected to an impact.

1. Configurate the ABS (ABS/TCS) HU/CM (when only replacing it). (See 

P–29 ABS (ABS/TCS) or DSC HU/CM 

CONFIGURATION

.)

2. Remove the battery, battery tray and battery tray bracket. (See 

G–3 BATTERY REMOVAL/INSTALLATION

.)

3. Remove the under cover.
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.

.

A6E6921W002

1

Brake pipe

2

Connector
(See 

P–29 Connector Removal Note

)

(See 

P–29 Connector Installation Note

3

ABS HU/CM
(See 

P–29 ABS HU/CM Removal/Installation Note

)

4

Stud

ABS/TCS 

P–29

P

Connector Removal Note

1. Pull the lock lever up and make it unlock.
2. Remove the connector.

ABS HU/CM Removal/Installation Note

1. When removing/installing the ABS HU/CM from/to the vehicle, attach a strip of protective tape on the ABS HU/

CM connector to prevent brake fluid from entering.

Connector Installation Note

1. Verify that the lock lever of the harness connector 

is completely pulled up.

End Of Sie

ABS (ABS/TCS) OR DSC HU/CM CONFIGURATION

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1. Connect the WDS or equivalent to the DLC-2.
2. Input vehicle information following the direction 

on the WDS or equivalent screen.

3. Select “Module programming”.
4. Select “Programmable module installation”.
5. Select “ABS/TCS”.
6. Retrieve DTCs by the WDS or equivalent, then 

verify that there is no DTC present.

• If DTC is present, perform applicable DTC 

inspection.

End Of Sie

ABS (ABS/TCS) HU/CM INSPECTION

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1. Disconnect the negative battery cable.
2. Connect the SST between the ABS (ABS/TCS) 

HU/CM and harness connector with the ignition 
switch off.

3. Attach the tester leads to the SST and inspect 

voltage referring the table below.

A6E6916W006

A6E6916W007

DLC-2

A6E3970W002

A6E6921W005

P–30

ABS/TCS 

Terminal Voltage Table (Reference)
(Engine is idling, and connector is connected unless otherwise indicated.)

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

A
B

RR wheel-speed 

RR wheel-speed 
sensor

Vehicle is stopped

0 (AC)

• Inspect related harness

• Inspect ABS wheel-speed 

sensor

• Inspect by using the wave profile.

(See 

P–31 Inspection Using An 

Oscilloscope (Reference)

)

C

F

LR wheel-speed 

LR wheel-speed 
sensor

Vehicle is stopped

0 (AC)

• Inspect by using the wave profile.

(See 

P–31 Inspection Using An 

Oscilloscope (Reference)

)

G
D

RF wheel-speed 

RF wheel-speed 
sensor

Vehicle is stopped

0 (AC)

• Inspect by using the wave profile.

(See 

P–31 Inspection Using An 

Oscilloscope (Reference)

)

I

E

LF wheel-speed 

LF wheel-speed 
sensor

Vehicle is stopped

0 (AC)

• Inspect by using the wave profile.

(See 

P–31 Inspection Using An 

Oscilloscope (Reference)

)

H

—

—

—

—

—

K

—

—

—

—

—

L

—

—

—

—

—

M

—

—

—

—

—

N

—

—

—

—

—

O

CAN-H

—

—

No need to check

—

P*

1

TCS OFF switch TCS OFF switch

When switch is 
pressed

Below 1.0

• Inspect related harness

• Inspect TCS OFF switch

When switch is not 
pressed

B+

Q

—

—

—

—

—

R

CAN-L

—

—

No need to check

—

S

—

—

—

—

—

T

—

—

—

—

—

U*

2

—

DLC

—

No need to check

—

V

Vehicle speed 
output

Cruise actuator, 

Wiper and washer 

switch, 

Audio unit,

Car-navigation unit, 

Headlight leveling 

actuator

Vehicle is stopped

0

• Inspect related harness

• Inspect ABS wheel-speed 

sensor

W

—

—

—

—

—

X

OBD

KLN terminal of 
DLC-2

It cannot be determined with terminal 
voltage whether the condition is good or 
bad because advanced function 
diagnostic output is performed with 
serial communication. Inspect with 
service codes.

• Inspect related harness

• Inspect ABS/TCS HU/CM

A6E6921W001

ABS/TCS 

P–31

P

*

1

: With  TCS

*

2

: Use this terminal at factory only, not used for inspection and repair at field

Inspection Using An Oscilloscope (Reference)
Wheel speed

•

• ABS/TCS HU/CM terminal:

RR : A ( + ) — B ( - )
LR : C ( + ) — F ( - )
RF : D ( + ) — G ( - )
LF : E ( + ) — I ( - )

• Oscilloscope setting:

1 V/DIV (Y), 2 ms/DIV (X), AC range

• Vehicle condition: Driving 30 km/h (18.6 mph)

Note

• As vehicle speed increases, period of wave 

shortens.

• If there is malfunctioning in the sensor rotor, 

wave profile warps.

Vehicle speed output 

•

• ABS/TCS HU/CM terminal: V( + ) — AC ( - )

• Oscilloscope setting:

1 V/DIV (Y), 5 ms/DIV (X), DC range

• Vehicle condition: Driving 30 km/h (18.6 mph)

Note

• As vehicle speed increases, period of wave 

shortens.

End Of Sie

TCS (DSC) OFF SWITCH REMOVAL/INSTALLATION

A6E692167650W02

1. Press the hooks of the TCS OFF switch and pull the switch out.
2. Disconnect the connector.
3. Install in the reverse order of removal.

End Of Sie

Y

Brake switch

Brake switch

Brake pedal is 
depressed

10—14

• Inspect related harness

Brake pedal is 
released

Below 0.5

Z

Power supply

Ignition switch

—

B+

• Inspect related harness

AA

Power supply 
(Solenoid valve)

Battery

—

B+

• Inspect related harness

AB

Power supply 
(ABS motor)

Battery

—

B+

AC

Ground

Ground

—

0

• Inspect related harness

AD

Ground

Ground

—

0

• Inspect related harness

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

Z3U0413W201

Z3U0413W202

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