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Home >> Infiniti >> 2020 >> QX80 Limited >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control System (Diagnostics) >> Description >> System (Brake Control) >> Brake Control System >> System Description >> Valve Operation
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Valve Operation

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

When Ordinary Brake is Applied 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.
G07023456Courtesy of NISSAN NORTH AMERICA, INC.

Name

Not activated

When depressing brake pedal

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)

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 caliper (fluid pressure)

--

Pressure increases

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

ABS is Operation (When Pressure Increases) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.
G07023457Courtesy of NISSAN NORTH AMERICA, INC.

Name

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 not supplied (open)

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 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 caliper (fluid pressure)

--

Pressure increases

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

ABS is Operation (When Pressure Holds) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.
G07023458Courtesy of NISSAN NORTH AMERICA, INC.

Name

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 not supplied (open)

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 not supplied (close)

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

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

ABS is Operation (When Pressure Decreases) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.
G07023459Courtesy of NISSAN NORTH AMERICA, INC.

Name

Not activated

When pressure decreases

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 not supplied (open)

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 not supplied (close)

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

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

VDC is Operation (When Pressure Increases) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.

Example: When other than rear LH wheel is operation in the figure.

G07023460Courtesy of NISSAN NORTH AMERICA, INC.

Name

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)

Only wheel that the pressure is to be increased: 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 (only wheel that the pressure is to be increased)

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

VDC is Operation (When Pressure Holds) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.

Example: When other than front LH wheel is operation in the figure.

G07023461Courtesy of NISSAN NORTH AMERICA, INC.

Name

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 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)

Only wheel that the pressure is to be holds: Power supply is supplied (close)

Wheel other than the one that the pressure is to be holds: 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 holds (only wheel that the pressure is to be holds)

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

VDC is Operation (When Pressure Decreases) 

NOTE: Control pressure sensor is applied to models with Advanced Driver Assistance System.

Example: When other than front LH wheel is operation in the figure.

G07023462Courtesy of NISSAN NORTH AMERICA, INC.

Name

Not activated

When pressure decreases

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)

Only wheel that the pressure is to be decreases: Power supply is supplied (close)

Wheel other than the one that the pressure is to be decreases: Power supply is not supplied (open)

ABS OUT valve

Power supply is not supplied (close)

Only wheel that the pressure is to be decreases: Power supply is supplied (open)

Wheel other than the one that the pressure is to be decreases: Power supply is not supplied (close)

Each caliper (fluid pressure)

--

Pressure decreases (only wheel that the pressure is to be decreases)

Front RH caliper

Front LH caliper

Rear RH caliper

Rear LH caliper

Component Parts and Function 

Component

Function

Pump

Operates the pump drive according to signals from ABS actuator and electric unit (control unit) by the motor.

Motor

Operates the motor drive according to signals from ABS actuator and electric unit (control unit).

Accumulator

The accumulator accumulates brake fluid conveyed by the motor and pump.

ABS IN valve

Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS actuator and electric unit (control unit).

ABS OUT valve

Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS actuator and electric unit (control unit).

Cut valve 1

Cut valve 2

Shuts off the ordinary brake line from master cylinder to signals from ABS actuator and electric unit (control unit).

Suction valve 1

Suction Valve 1 switches the brake line to convey accumulator pressure to the front system, according to a signal transmitted from the ABS actuator and electric unit (control unit).

Suction valve 2

Suction valve 2 releases accumulator pressure, according to a signal transmitted from the ABS actuator and electric unit (control unit).

Control pressure sensor *

Detects the brake fluid pressure of rear brake caliper and transmits a signal to ABS actuator and electric unit (control unit).

Accumulator pressure sensor

The accumulator pressure sensor detects brake fluid pressure accumulated in the accumulator and conveys the detected result to the ABS actuator and electric unit (control unit).

Master cylinder pressure sensor

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

*: Models with Advanced Driver Assistance System