Valve Operation (Abs Function And EBD Function): Notes

The control unit built in the ABS actuator and electric unit (control unit) controls fluid pressure of the brake calipers, respectively, by operating each valve.

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

Fig 1: ABS Actuator And Electric Unit - Circuit Diagram (During Pressure Increases)

Courtesy of NISSAN NORTH AMERICA, INC.

Name	Not activated	During 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 caliper (fluid pressure)	-	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 reservoir 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 reservoir 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 reservoir 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 reservoir because the ABS OUT valve is closed.

When ABS Function is Starts Operating (During Pressure Holds)

Fig 2: ABS Function Diagram (During Pressure Holds)

Courtesy of NISSAN NORTH AMERICA, INC.

Name	Not activated	During 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 caliper (fluid pressure)	-	Pressure holds

During pressure front RH brake caliper holds

Since the ABS IN valve and the ABS OUT valve are closed, the front RH brake caliper, electrically-driven intelligent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the front RH brake caliper.

During pressure front LH brake caliper holds

Since the ABS IN valve and the ABS OUT valve are closed, the front LH brake caliper, electrically-driven intelligent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the front LH brake caliper.

During pressure rear RH brake caliper holds

Since the ABS IN valve and the ABS OUT valve are closed, the rear RH brake caliper, electrically-driven intelligent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the rear RH brake caliper.

During pressure rear LH brake caliper holds

Since the ABS IN valve and the ABS OUT valve are closed, the rear LH brake caliper, electrically-driven intelligent brake unit, and reservoir are blocked. This maintains fluid pressure applied on the rear LH brake caliper.

When ABS Function is in Operation (During Pressure Decreases)

Fig 3: ABS Function Diagram (During Pressure Decreases)

Courtesy of NISSAN NORTH AMERICA, INC.

Name	Not activated	During 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 caliper (fluid pressure)	-	Pressure decreases

During pressure front RH brake caliper decreases

Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the front RH brake caliper is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the electrically-driven intelligent brake unit by the pump.

During pressure front LH brake caliper decreases

Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the front LH brake caliper is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the electrically-driven intelligent brake unit by the pump.

During pressure rear RH brake caliper decreases

Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the rear RH brake caliper is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the electrically-driven intelligent brake unit by the pump.

During pressure rear LH brake caliper decreases

Since the ABS IN valve is closed and the ABS OUT valve is opened, fluid pressure applied on the rear LH brake caliper is supplied to the reservoir through the ABS OUT valve. This fluid pressure decreases when sent to the electrically-driven intelligent brake unit by the pump.

When Brake Release

Fig 4: ABS Function Diagram (When Brake Release)

Courtesy of NISSAN NORTH AMERICA, INC.

Name	Not activated	During brake release
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 caliper (fluid pressure)	-	Pressure decreases

During front RH brake caliper release

Brake fluid is supplied to the front RH brake caliper through the return check valve of the ABS IN valve and the cut valve 2, and returns to the electrically-driven intelligent brake unit.

During front LH brake caliper release

Brake fluid is supplied to the front LH brake caliper through the return check valve of the ABS IN valve and the cut valve 1, and returns to the electrically-driven intelligent brake unit.

During rear RH brake caliper release

Brake fluid is supplied to the rear RH brake caliper through the return check valve of the ABS IN valve and the cut valve 1, and returns to the electrically-driven intelligent brake unit.

During rear LH brake caliper release

Brake fluid is supplied to the rear LH brake caliper through the return check valve of the ABS IN valve and the cut valve 2, and returns to the electrically-driven intelligent brake unit.