Nissan Pathfinder. Manual - part 238

SYSTEM

BRC-11

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

SYSTEM

System Diagram

INFOID:0000000009177244

System Description

INFOID:0000000009177245

• The system switches fluid pressure of each brake caliper 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 function, TCS function, ABS function, EBD function and hill start assist function.

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

occurs.

INPUT SIGNAL AND OUTPUT SIGNAL

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

VDC function, TCS function, ABS function and EBD function

AWFIA0897GB

Component

Signal description

Yaw rate/side/decel G sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via com-
munication line*

1

:

• Yaw rate signal
• Side G sensor signal
• Decel G sensor 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
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN 
communication.
• Target throttle position signal

TCM

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN 
communication:
• Shift position signal

BRC-12

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

SYSTEM

*1: Communication line between yaw rate/side/decel G sensor and ABS actuator and electric unit (control unit)

VALVE OPERATION (ABS AND EBD)

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

When ordinary brake is applied and ABS is in operation (when pressure increases).

When front RH wheel caliper pressure increases

Steering angle sensor

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

Combination meter

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

Component

Signal description

JPFIC0159GB

Name

Not activated

When Pressure Increases

Cut valve 1

Power supply is not supplied (open)

Power supply is not supplied (open)

Cut valve 2

Power supply is not supplied (open)

Power supply is not 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 caliper (fluid pressure)

—

Pressure increases

SYSTEM

BRC-13

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

C

D

E

G

H

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J

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A

B

BRC

N

O

P

• Motor is activated. Brake fluid is pressurized by pump and is sent to secondary line through cut valve 2. At

the same time, pressurized brake fluid is supplied to front RH caliper through ABS IN valve.

When front LH wheel caliper pressure increases

• Motor is activated. Brake fluid is pressurized by pump and is sent to primary line through cut valve 1. At the

same time, pressurized brake fluid is supplied to front LH wheel caliper through ABS IN valve.

When rear RH wheel caliper pressure increases

• Motor is activated. Brake fluid is pressurized by pump and is sent to primary line through cut valve 1. At the

same time, pressurized brake fluid is supplied to rear RH wheel caliper through ABS IN valve.

When rear LH wheel caliper pressure increases

• Motor is activated. Brake fluid is pressurized by pump and is sent to secondary line through cut valve 2. At

the same time, pressurized brake fluid is supplied to rear LH wheel caliper through ABS IN valve.

When ABS operation starts (when pressure holds)

When front RH wheel caliper pressure holds

• Motor is activated. Brake fluid is pressurized by pump and is sent to secondary line through cut valve 2. At

the same time, because ABS IN valve and ABS OUT valve are closed, fluid pressure holds.

When front LH wheel caliper pressure holds

• Motor is activated. Brake fluid is pressurized by pump and is sent to primary line through cut valve 1. At the

same time, because ABS IN valve and ABS OUT valve are closed, fluid pressure holds.

JPFIC0160GB

Name

Not activated

When pressure holds

Cut valve 1

Power supply is not supplied (open)

Power supply is not supplied (open)

Cut valve 2

Power supply is not supplied (open)

Power supply is not supplied (open)

ABS IN valve

Power supply is not supplied (open)

Power supply is supplied (close)

ABS OUT valve

Power supply is not supplied (close)

Power supply is not supplied (close)

Each caliper (fluid pressure)

—

Pressure holds

BRC-14

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

SYSTEM

When rear RH wheel caliper pressure holds

• Motor is activated. Brake fluid is pressurized by pump and is sent to primary line through cut valve 1. At the

same time, because ABS IN valve and ABS OUT valve are closed, fluid pressure holds.

When rear LH wheel caliper pressure holds

• Motor is activated. Brake fluid is pressurized by pump and is sent to secondary line through cut valve 2. At

the same time, because ABS IN valve and ABS OUT valve are closed, fluid pressure holds.

ABS is in operation (when pressure decreases)

When front RH wheel caliper pressure decreases

• Being supplied to reservoir through ABS OUT valve, the fluid pressure of brake caliper is decreased.

When front LH wheel caliper pressure decreases

• Being supplied to reservoir through ABS OUT valve, the fluid pressure of brake caliper is decreased.

When rear RH wheel caliper pressure decreases

• Being supplied to reservoir through ABS OUT valve, the fluid pressure of brake caliper is decreased.

When rear LH wheel caliper pressure decreases

• Being supplied to reservoir through ABS OUT valve, the fluid pressure of brake caliper is decreased.

Component Parts and Function

JPFIC0161GB

Name

Not activated

When pressure decreases

Cut valve 1

Power supply is not supplied (open)

Power supply is not supplied (open)

Cut valve 2

Power supply is not supplied (open)

Power supply is not supplied (open)

ABS IN valve

Power supply is not supplied (open)

Power supply is supplied (close)

ABS OUT valve

Power supply is not supplied (close)

Power supply is supplied (open)

Each caliper (fluid pressure)

—

Pressure decreases