Valve Operation (Abs Function)

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

When Brake Pedal is Applied 

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Component parts	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)
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 increases

During pressure front RH brake increases

• When the cut valve 1 and the ABS IN valve opens, brake fluid is supplied to the front RH brake from the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS OUT valve is closed.

During pressure front LH brake increases

• When the cut valve 2 and the ABS IN valve opens, brake fluid is supplied to the front LH brake from the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS OUT valve is closed.

During pressure rear RH brake increases

• When the cut valve 2 and the ABS IN valve opens, brake fluid is supplied to the rear RH brake from the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS OUT valve is closed.

During pressure rear LH brake increases

• When the cut valve 1 and the ABS IN valve opens, brake fluid is supplied to the rear LH brake from the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS OUT valve is closed.

When ABS Function is in Operation (During Pressure Increases) 

Courtesy of NISSAN NORTH AMERICA, INC.

Component parts	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)
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 increases

During pressure front RH brake increases

• Brake fluid is supplied to the front RH brake from the master cylinder through the cut valve 1 and the ABS IN valve. Since the suction valve 1 and the ABS OUT valve is closed, the fluid does not flow into the reservoir. The amount of brake fluid supplied to the front RH brake from the master cylinder is controlled according to time that the ABS IN valve is not energized (time that the ABS IN valve is open).

During pressure front LH brake increases

• Brake fluid is supplied to the front LH brake from the master cylinder through the cut valve 2 and the ABS IN valve. Since the suction valve 2 and the ABS OUT valve is closed, the fluid does not flow into the reservoir. The amount of brake fluid supplied to the front LH brake from the master cylinder is controlled according to time that the ABS IN valve is not energized (time that the ABS IN valve is open).

During pressure rear RH brake increases

• Brake fluid is supplied to the rear RH brake from the master cylinder through the cut valve 2 and the ABS IN valve. Since the suction valve 2 and the ABS OUT valve is closed, the fluid does not flow into the reservoir. The amount of brake fluid supplied to the rear RH brake from the master cylinder is controlled according to time that the ABS IN valve is not energized (time that the ABS IN valve is open).

During pressure rear LH brake increases

• Brake fluid is supplied to the rear LH brake from the master cylinder through the cut valve 1 and the ABS IN valve. Since the suction valve 1 and the ABS OUT valve is closed, the fluid does not flow into the reservoir. The amount of brake fluid supplied to the rear LH brake from the master cylinder is controlled according to time that the ABS IN valve is not energized (time that the ABS IN valve is open).

When ABS Function is Operating (During Pressure Holds) 

Courtesy of NISSAN NORTH AMERICA, INC.

Component parts	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)
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 supplied (close)
ABS OUT valve	Power supply is not supplied (close)	Power supply is not supplied (close)
Each brake (fluid pressure)	--	Pressure holds

During pressure front RH brake holds

• Since the ABS IN valve and the ABS OUT valve are closed, the front RH brake, master cylinder, and reservoir are blocked. This maintains fluid pressure applied on the front RH brake.

During pressure front LH brake holds

• Since the ABS IN valve and the ABS OUT valve are closed, the front LH brake, master cylinder, and reservoir are blocked. This maintains fluid pressure applied on the front LH brake.

During pressure rear RH brake holds

• Since the ABS IN valve and the ABS OUT valve are closed, the rear RH brake, master cylinder, and reservoir are blocked. This maintains fluid pressure applied on the rear RH brake.

During pressure rear LH brake holds

• Since the ABS IN valve and the ABS OUT valve are closed, the rear LH brake, master cylinder, and reservoir are blocked. This maintains fluid pressure applied on the rear LH brake.

When ABS Function is in Operation (During Pressure Decreases) 

Courtesy of NISSAN NORTH AMERICA, INC.

Component parts	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)
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 supplied (close)
ABS OUT valve	Power supply is not supplied (close)	Power supply is supplied (open)
Each brake (fluid pressure)	--	Pressure decreases

During pressure front RH brake decreased

• Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the front RH brake is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the master cylinder by the pump.

During pressure front LH brake decreased

• Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the front LH brake is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the master cylinder by the pump.

During pressure rear RH brake decreased

• Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the rear RH brake is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the master cylinder by the pump.

During pressure rear LH brake decreased

• Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the rear LH brake is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the master cylinder by the pump.

When Brake Release 

Courtesy of NISSAN NORTH AMERICA, INC.

Component pars	Not activated	When pressure decrease
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 brake (fluid pressure)	--	Pressure decreases

During pressure front RH brake release

• Brake fluid is supplied to the front RH brake through the return check valve of the ABS IN valve and the cut valve 1, and returns to the master cylinder.

During pressure front LH brake release

• Brake fluid is supplied to the front LH brake through the return check valve of the ABS IN valve and the cut valve 2, and returns to the master cylinder.

During pressure rear RH brake release

• Brake fluid is supplied to the rear RH brake through the return check valve of the ABS IN valve and the cut valve 2, and returns to the master cylinder.

During pressure rear LH brake release

• Brake fluid is supplied to the rear LH brake through the return check valve of the ABS IN valve and the cut valve 1, and returns to the master cylinder.

Component Parts and Function 

Component parts	Function
Pump	Pressure the brake fluid and send. Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.
Motor	Activates the pump 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.
Suction valve 1 Suction valve 2	Supplies the brake fluid from master cylinder to the pump.
ABS IN valve	Switches the fluid pressure line to increase or hold according.
ABS OUT valve	Switches the fluid pressure line to increase, hold or decrease according.
Return check valve	Returns the brake fluid from each brake to master cylinder by bypassing orifice of each valve when brake is released.
Reservoir	Temporarily reserves the brake fluid drained from each brake, so that pressure efficiently decreases when decreasing pressure of each brake.
Pressure sensor	Detects the brake fluid pressure and transmits signal to ABS actuator and electric unit (control unit).