Nissan X-Trail 32. Manual - part 141

BRC-30

< SYSTEM DESCRIPTION >

[WITH VDC (ESP)]

SYSTEM

SYSTEM

System Description

INFOID:0000000010723631

• The system switches fluid pressure of each brake to increase, to hold or to decrease according to signals

from control unit in ABS actuator and electric unit (control unit). This control system is applied to VDC func-
tion, TCS function, ABS function, EBD function, brake limited slip differential (BLSD) function, brake assist
function, brake force distribution function, hill start assist function and advanced hill descent control function
(4WD models with gasoline engine).

• Fail-safe function is available for each function and is activated by each function when system malfunction

occurs.

SYSTEM DIAGRAM

NOTE:
• 4WD control unit is applied to 4WD models.
• TCM is applied to CVT models.
• hill descent control switch is applied to 4WD models with gasoline engine.

INPUT SIGNAL AND OUTRET SIGNAL

Major signal transmission between each unit via communication lines is shown in the following table.

JSFIA2365GB

SYSTEM

BRC-31

< SYSTEM DESCRIPTION >

[WITH VDC (ESP)]

C

D

E

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H

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A

B

BRC

N

O

P

Component parts

Signal description

Combination meter

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Parking brake switch signal
• Brake fluid level switch signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via 
CAN communication.
• ABS warning lamp signal
• VDC OFF indicator lamp signal
• VDC warning lamp signal
• Brake warning lamp signal
• hill start assist indicator lamp signal

• hill descent control indicator lamp signal

*1

Mainly receives the following signals from ABS actuator and electric unit (control unit) via 
chassis control module via CAN communication.
• hill start assist display request signal

• hill descent control display request signal

*1

TCM

*2

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• N range signal
• P range signal
• R range signal
• Current gear position signal
• Shift position signal
• TCM malfunction signal

ECM

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Accelerator pedal position signal
• Engine speed signal
• Engine status signal
• ECM malfunction signal

IPDM E/R

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Ignition switch ON signal

BCM

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Stop lamp switch signal
• Brake pedal position switch signal
• Cranking signal
• Ignition switch ON signal

Chassis control module

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Active trace control signal
• Active ride control signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via 
CAN communication.
• hill start assist display request signal

• hill descent control display request signal

*1

Mainly transmits the following signals to combination meter via CAN communication.
• hill start assist display request signal

• hill descent control display request signal

*1

Electric parking brake control module

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Electric parking brake operation signal

4WD control unit

*3

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• 4WD malfunction signal
• 4WD operation signal

Steering angle sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication.
• Steering angle sensor signal

BRC-32

< SYSTEM DESCRIPTION >

[WITH VDC (ESP)]

SYSTEM

*1: 4WD models with gasoline engine
*2: CVT models
*3: 4WD models

VALVE OPERATION [VDC FUNCTION, TCS FUNCTION, BRAKE LIMITED SLIP DIFFERENTIAL
(BLSD) FUNCTION, BRAKE ASSIST FUNCTION, BRAKE FORCE DISTRIBUTION FUNCTION, hill
start assist FUNCTION AND ADVANCED hill descent control FUNCTION (4WD MODELS WITH
GASOLINE ENGINE)]

Each valve is operated and fluid pressure of brake is controlled.

VDC Function, TCS Function, Brake Limited Slip Differential (BLSD) Function, Brake Assist Function, Brake force
distribution Function, hill start assist Function and Advanced hill descent control Function (4WD Models with Gaso-
line Engine) are in Operation (During Pressure Increases)

During pressure front RH brake increases

• Brake fluid is conveyed to the pump from the master cylinder through suction valve 1 and is pressurized by

the pump operation. The pressurized brake fluid is supplied to the front RH brake through the ABS IN valve.
For the left brake, brake fluid pressure is maintained because the pressurization is unnecessary. The pres-
surization for the left brake is controlled separately from the right brake.

During pressure front LH brake increases

• Brake fluid is conveyed to the pump from the master cylinder through suction valve 2 and is pressurized by

the pump operation. The pressurized brake fluid is supplied to the front LH brake through the ABS IN valve.

JSFIA1735GB

Component parts

Not activated

When pressure increases

Cut valve 1

Power supply is not supplied (open)

Power supply is supplied (close)

Cut valve 2

Power supply is not supplied (open)

Power supply is supplied (close)

Suction valve 1

Power supply is not supplied (close)

Power supply is supplied (open)

Suction valve 2

Power supply is not supplied (close)

Power supply is supplied (open)

ABS IN valve

Power supply is not supplied (open)

Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Power supply is not supplied (close)

Each brake (fluid pressure)

—

Pressure increases

SYSTEM

BRC-33

< SYSTEM DESCRIPTION >

[WITH VDC (ESP)]

C

D

E

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M

A

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BRC

N

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P

For the right brake, brake fluid pressure is maintained because the pressurization is unnecessary. The pres-
surization for the right brake is controlled separately from the left brake.

During pressure rear RH brake increases

• Brake fluid is conveyed to the pump from the master cylinder through suction valve 2 and is pressurized by

the pump operation. The pressurized brake fluid is supplied to the rear RH brake through the ABS IN valve.
For the left brake, brake fluid pressure is maintained because the pressurization is unnecessary. The pres-
surization for the left brake is controlled separately from the right brake.

During pressure rear LH brake increases

• Brake fluid is conveyed to the pump from the master cylinder through suction valve 1 and is pressurized by

the pump operation. The pressurized brake fluid is supplied to the rear LH brake through the ABS IN valve.
For the right brake, brake fluid pressure is maintained because the pressurization is unnecessary. The pres-
surization for the right brake is controlled separately from the left brake.

VDC Function, TCS Function, Brake Limited Slip Differential (BLSD) Function, Brake Assist Function, Brake force
distribution Function, hill start assist Function and Advanced hill descent control Function (4WD Models with Gaso-
line Engine) are in Operation (During Pressure Holds)

During pressure front RH brake holds

• Since the cut valve 1 and the suction valve 1 are closed, the front RH brake, master cylinder, and reservoir

are blocked. This maintains fluid pressure applied on the front RH brake. The pressurization for the left
brake is controlled separately from the right brake.

JSFIA1736GB

Component parts

Not activated

When pressure holds

Cut valve 1

Power supply is not supplied (open)

Power supply is supplied (close)

Cut valve 2

Power supply is not supplied (open)

Power supply is supplied (close)

Suction valve 1

Power supply is not supplied (close)

Power supply is not supplied (close)

Suction valve 2

Power supply is not supplied (close)

Power supply is not supplied (close)

ABS IN valve

Power supply is not supplied (open)

Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Power supply is not supplied (close)

Each brake (fluid pressure)

—

Pressure holds