Content .. 305 306 307 308 ..

Nissan Leaf. Manual - part 307

BRC-18

< SYSTEM DESCRIPTION >

[WITH VDC]

SYSTEM

During pressure front RH brake caliper increases

• Brake fluid is conveyed to the pump from the electrically-driven intelligent brake unit through suction valve 2

and is pressurized by the pump operation. The pressurized brake fluid is supplied to the front RH brake cali-

per through the ABS IN valve. For the left caliper, brake fluid pressure is maintained because the pressuriza-

tion is unnecessary. The pressurization for the left caliper is controlled separately from the right caliper.

During pressure front LH brake caliper increases

• Brake fluid is conveyed to the pump from the electrically-driven intelligent brake unit through suction valve 1

and is pressurized by the pump operation. The pressurized brake fluid is supplied to the front LH brake cali-

per through the ABS IN valve. For the right caliper, brake fluid pressure is maintained because the pressur-

ization is unnecessary. The pressurization for the right caliper is controlled separately from the left caliper.

During pressure rear RH brake caliper increases

• Brake fluid is conveyed to the pump from the electrically-driven intelligent brake unit through suction valve 1

and is pressurized by the pump operation. The pressurized brake fluid is supplied to the rear RH brake cali-

per through the ABS IN valve. For the left caliper, brake fluid pressure is maintained because the pressuriza-

tion is unnecessary. The pressurization for the left caliper is controlled separately from the right caliper.

During pressure rear LH brake caliper increases

• Brake fluid is conveyed to the pump from the electrically-driven intelligent brake unit through suction valve 2

and is pressurized by the pump operation. The pressurized brake fluid is supplied to the rear LH brake cali-

per through the ABS IN valve. For the right caliper, brake fluid pressure is maintained because the pressur-

ization is unnecessary. The pressurization for the right caliper is controlled separately from the left caliper.

When VDC Function, TCS Function, Brake Limited Slip Differential (BLSD) Function Brake Assist Function are Starts
Operating (During Pressure Holds)

ABS OUT valve

Power supply is not supplied (close)

Each brake caliper (fluid pressure)

—

Pressure increases

Name

Not activated

During pressure increases

JSFIA1836GB

Name

Not activated

During 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)

SYSTEM

BRC-19

< SYSTEM DESCRIPTION >

[WITH VDC]

BRC

During pressure front RH brake caliper holds

• Since the cut valve 2 and the suction valve 2 are closed, the front RH brake caliper, electrically-driven intelli-

gent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the front RH brake cali-

per. The pressurization for the left caliper is controlled separately from the right caliper.

During pressure front LH brake caliper holds

• Since the cut valve 1 and the suction valve 1 are closed, the front LH brake caliper, electrically-driven intelli-

gent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the front LH brake cali-

per. The pressurization for the right caliper is controlled separately from the left caliper.

During pressure rear RH brake caliper holds

• Since the cut valve 1 and the suction valve 1 are closed, the rear RH brake caliper, electrically-driven intelli-

gent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the rear RH brake cali-

per. The pressurization for the left caliper is controlled separately from the right caliper.

During pressure rear LH brake caliper holds

• Since the cut valve 2 and the suction valve 2 are closed, the rear LH brake caliper, electrically-driven intelli-

gent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the rear LH brake cali-

per. The pressurization for the right caliper is controlled separately from the left caliper.

When VDC Function, TCS Function, Brake Limited Slip Differential (BLSD) Function and Brake Assist Function are
in Operation (During Pressure Decreases)

Suction valve 1

Power supply is not supplied (close)

Suction valve 2

Power supply is not supplied (close)

ABS IN valve

Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Each brake caliper (fluid pressure)

—

Pressure holds

Name

Not activated

During pressure holds

JSFIA1837GB

Name

Not activated

During pressure decreases

Cut valve 1

Power supply is not supplied (open)

Cut valve 2

Power supply is not supplied (open)

BRC-20

< SYSTEM DESCRIPTION >

[WITH VDC]

SYSTEM

During pressure front RH brake caliper decreases

• Since the suction valve 2 and the ABS OUT valve close and the cut valve 2 and the ABS IN valve open, the

fluid pressure applied on the front RH brake caliper is reduced by supplying the fluid pressure to the electri-

cally-driven intelligent brake unit via the ABS IN valve and the cut valve 2. The pressurization for the right

caliper is controlled separately from the left caliper.

During pressure front LH brake caliper decreases

• Since the suction valve 1 and the ABS OUT valve close and the cut valve 1 and the ABS IN valve open, the

fluid pressure applied on the front LH brake caliper is reduced by supplying the fluid pressure to the electri-

cally-driven intelligent brake unit via the ABS IN valve and the cut valve 2. The pressurization for the left cal-

iper is controlled separately from the right caliper.

During pressure rear RH brake caliper decreases

• Since the suction valve 1 and the ABS OUT valve close and the cut valve 1 and the ABS IN valve open, the

fluid pressure applied on the rear RH brake caliper is reduced by supplying the fluid pressure to the electri-

cally-driven intelligent brake unit via the ABS IN valve and the cut valve 2. The pressurization for the right

caliper is controlled separately from the left caliper.

During pressure rear LH brake caliper decreases

• Since the suction valve 2 and the ABS OUT valve close and the cut valve 2 and the ABS IN valve open, the

fluid pressure applied on the rear LH brake caliper is reduced by supplying the fluid pressure to the electri-

cally-driven intelligent brake unit via the ABS IN valve and the cut valve 2. The pressurization for the left cal-

iper is controlled separately from the right caliper.

Component Parts and Function

VALVE OPERATION (ABS FUNCTION AND EBD FUNCTION)

The control unit built in the ABS actuator and electric unit (control unit) controls fluid pressure of the brake cal-

ipers, respectively, by operating each valve.

Suction valve 1

Power supply is not supplied (close)

Suction valve 2

Power supply is not supplied (close)

ABS IN valve

Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Each brake caliper (fluid pressure)

—

Pressure decreases

Name

Not activated

During pressure decreases

Component

Function

Pump

Pressurized brake fluid from electrically-driven intelligent brake unit is supplied to each caliper.

Motor

Activates the pump according to signals from control unit part.

Cut valve 1
Cut valve 2

Shuts off the ordinary brake line from electrically-driven intelligent brake unit.

Suction valve 1
Suction valve 2

Supplies the brake fluid from electrically-driven intelligent brake unit to the pump.

ABS IN valve

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

ABS OUT valve

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

Inlet valve

Brake fluid sucked from the reservoir by the pump does not backflow.

Outlet valve

Brake fluid discharged from the pump does not backflow.

Return check valve

Returns the brake fluid from brake caliper to electrically-driven intelligent brake unit by bypassing
orifice of each valve when brake is released.

Reservoir

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

Master cylinder pressure sensor

Detects the brake fluid pressure from master cylinder part and transmits signal to ABS actuator and
electric unit (control unit).

SYSTEM

BRC-21

< SYSTEM DESCRIPTION >

[WITH VDC]

BRC

When Brake Pedal is Applied or ABS Function is in Operation (During Pressure Increases)

During pressure front RH brake caliper increases

• When the cut valve 2 and the ABS IN valve opens, brake fluid is supplied to the front RH brake caliper from

the electrically-driven intelligent brake unit through the ABS IN valve. Brake fluid does not flow into the reser-

voir because the ABS OUT valve is closed.

During pressure front LH brake caliper increases

• When the cut valve 1 and the ABS IN valve opens, brake fluid is supplied to the front LH brake caliper from

the electrically-driven intelligent brake unit through the ABS IN valve. Brake fluid does not flow into the reser-

voir because the ABS OUT valve is closed.

During pressure rear RH brake caliper increases

• When the cut valve 1 and the ABS IN valve opens, brake fluid is supplied to the rear RH brake caliper from

the electrically-driven intelligent brake unit through the ABS IN valve. Brake fluid does not flow into the reser-

voir because the ABS OUT valve is closed.

During pressure rear LH brake caliper increases

• When the cut valve 2 and the ABS IN valve opens, brake fluid is supplied to the rear LH brake caliper from

the electrically-driven intelligent brake unit through the ABS IN valve. Brake fluid does not flow into the reser-

voir because the ABS OUT valve is closed.

JSFIA1838GB

Name

Not activated

During pressure increases

Cut valve 1

Power supply is not supplied (open)

Cut valve 2

Power supply is not supplied (open)

Suction valve 1

Power supply is not supplied (close)

Suction valve 2

Power supply is not supplied (close)

ABS IN valve

Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Each brake caliper (fluid pressure)

—

Pressure increases

Content .. 305 306 307 308 ..