Nissan Pathfinder. Manual — part 239

SYSTEM

BRC-15

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

VALVE OPERATION (OTHER THAN ABS AND EBD)

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

NOTE:

There is no operation to hold and increase pressure for functions other than ABS and EBD.

When Pressure Increases

Component

FUNCTION

Reservoir

Temporarily reserves the brake fluid drained from brake caliper, so that pressure efficiently decreas-
es when decreasing pressure of brake caliper.

Pump

Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.

Motor

Drives the pump according to signals from control unit.

ABS IN valve

Switches the fluid pressure line to increase or hold according to signals from control unit.

ABS OUT valve

Switches the fluid pressure line to increase, hold or decrease according to signals from control unit.

Return check valve

Returns the brake fluid from brake caliper to master cylinder by bypassing orifice of each valve when
brake is released.

Cut valve 1
Cut valve 2

Performs the duty control of fluid pressure increased by pump according to signals from control unit.

Pressure Sensor

Detects the brake pedal operation amount.

JPFIC0162GB

BRC-16

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

SYSTEM

When front RH wheel caliper pressure increases

• Motor is activated. Brake fluid from pump is supplied to front RH wheel caliper through ABS IN valve. For

other wheel, ABS IN valve is closed and brakes fluid is not supplied to caliper.

When front LH wheel caliper pressure increases

• Motor is activated. Brake fluid from pump is supplied to front LH wheel caliper through ABS IN valve. For

other wheel, ABS IN valve is closed and brakes fluid is not supplied to caliper.

When rear RH wheel caliper pressure increases

• Motor is activated. Brake fluid from pump is supplied to front RH wheel caliper through ABS IN valve. For

other wheel, ABS IN valve is closed and brakes fluid is not supplied to caliper.

When rear LH wheel caliper pressure increases

• Motor is activated. Brake fluid from pump is supplied to front LH wheel caliper through ABS IN valve. For

other wheel, ABS IN valve is closed and brakes fluid is not supplied to caliper.

Name

Not activated

When Pressure Increases

Cut valve 1

Power supply is not supplied (open)

Wheel other than the one that the pressure
is to be increased: Power supply is not sup-

plied (open)

Only wheel that the pressure is to be in-

creased: Power supply is supplied (close)

Cut valve 2

Power supply is not supplied (open)

Wheel other than the one that the pressure
is to be increased: Power supply is not sup-

plied (open)

Only wheel that the pressure is to be in-

creased: Power supply is supplied (close)

ABS IN valve

Power supply is not supplied (open)

Only wheel that the pressure is to be in-

creased: Power supply is not supplied

(open)

Wheel other than the one that the pressure
is to be increased: 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 increases

SYSTEM

BRC-17

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

Released

When front RH wheel caliper pressure decreases

• Being returned to master cylinder through ABS IN valve, fluid pressure of brake caliper is decreased.

When front LH wheel caliper pressure decreases

• Being returned to master cylinder through ABS IN valve, fluid pressure of brake caliper is decreased.

When rear RH wheel caliper pressure decreases

• Being returned to master cylinder through ABS IN valve, fluid pressure of brake caliper is decreased.

When rear LH wheel caliper pressure decreases

• Being returned to master cylinder through ABS IN valve, fluid pressure of brake caliper is decreased.

Component Parts and Function

JPFIC0163GB

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 not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Power supply is supplied (open)

Each caliper (fluid pressure)

—

Pressure decreases

Component

Function

Reservoir

Temporarily reserves the brake fluid drained from brake caliper so that pressure efficiently decreas-
es when decreasing pressure of brake caliper.

Pump

Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.

Motor

Drives the pump according to signals from control unit.

ABS IN valve

Switches the fluid pressure line to increase or hold according to signals from control unit.

BRC-18

< SYSTEM DESCRIPTION >

[VDC/TCS/ABS]

SYSTEM

CONDITIONS FOR TURNING ON THE WARNING LAMP

ABS Warning Lamp

• Turns ON at the same time as VDC warning lamp when either ABS function or EBD function is malfunction-

ing.

• Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.

Brake Warning Lamp

• Turns ON at the same time as ABS warning lamp and VDC warning lamp when EBD function is malfunction-

ing.

• Turns ON when ignition switch turns ON and turns OFF when the system is normal for bulb check purposes.

VDC Warning Lamp

• Turns ON when either VDC function, TCS function, ABS function or EBD function is malfunctioning.

• Turns ON when ignition switch turns ON and turns OFF when the system is normal for bulb check purposes.

ABS OUT valve

Switches the fluid pressure line to increase, hold or decrease according to signals from control unit.

Return check valve

Returns the brake fluid from brake caliper to master cylinder by bypassing orifice of each valve when
brake is released.

Cut valve 1
Cut valve 2

Performs the duty control of fluid pressure increased by pump according to signals from control unit.

Pressure Sensor

Detects the brake pedal operation amount.

Component

Function

Condition (status)

ABS warning lamp

Ignition switch OFF

OFF

For approx. 1 second after the ignition switch is turned ON

ON

Approx. 1 second after ignition switch is turned ON (when the sys-
tem is in normal operation)

OFF

ABS function is malfunctioning

ON

EBD function is malfunctioning

ON

Condition (status)

Brake warning lamp

Ignition switch OFF

OFF

For approx. 1 seconds after the ignition switch is turned ON

ON

Approx. 1 second after ignition switch is turned ON (when the sys-
tem is in normal operation)

OFF

After engine starts

OFF

When parking brake operates (parking brake switch ON)

ON

When brake booster vacuum decreases

ON

When vacuum sensor is malfunctioning

ON

When brake fluid is less than the specified level (brake fluid level
switch ON)

ON

ABS function is malfunctioning

OFF

EBD function is malfunctioning

ON

Condition (status)

VDC warning lamp

Ignition switch OFF

OFF

For approx. 1 second after the ignition switch is turned ON

ON

Approx. 1 second after ignition switch is turned ON (when the sys-
tem is in normal operation)

OFF

VDC function is malfunctioning

ON

TCS function is malfunctioning

ON