COMPONENT PARTSBRC-9
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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Component DescriptionINFOID:0000000009463742
ABS Actuator and Electric Unit (Control Unit)INFOID:0000000009463743
Electric unit (control unit) is integrated with actuator and comprehensively controls VDC function, TCS func-
tion, ABS function and EBD function.
ELECTRIC UNIT (CONTROL UNIT)
• Brake fluid pressure is controlled according to signals from each sensor.
• If malfunction is detected, t he system enters fail-safe mode.
ACTUATOR
The following components are integrated with ABS actuator.
Pump
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).
Motor Relay
Operates the motor ON/OFF according to signals fr om ABS actuator and electric unit (control unit).
Actuator Relay (Main Relay)
Operates each valve ON/OFF according to signals fr om ABS actuator and electric unit (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.
Cut Valve 1, Cut Valve 2
Shuts off the ordinary brake line from master cylinder, when VDC function and TCS function are activated.
7. Rear wheel sensor LH (RH similar) 8. VDC OFF switch 9. Steering angle sensor
(view with steering wheel removed)
10. Parking brake switch 11. Stop lamp switch 12. Combination meter
Component Reference/Function
ABS actuator and electric unit (control unit) BRC-9, "ABS Actuator and Electric Unit (Control Unit)"
Wheel sensorBRC-10, "Wheel Sensor and Sensor Rotor"
Stop lamp switchBRC-10, "Stop Lamp Switch"
Steering angle sensorBRC-10, "Steering Angle Sensor"
Vacuum sensorBRC-10, "Vacuum Sensor"
VDC OFF switchBRC-11, "VDC OFF Switch"
Brake fluid level switchBRC-10, "Brake Fluid Level Switch"
Parking brake switchBRC-11, "Parking Brake Switch"
ABS warning lamp
BRC-12, "VDC/TCS/ABS : System Description"
Brake warning lamp
VDC OFF indicator lamp
SLIP indicator lamp
ECM Transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Accelerator pedal position signal
• Engine speed signal
• Target throttle position signal
TCM Transmits the current gear position signal
to ABS actuator and electric unit (control
unit) via CAN communication.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-10
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
COMPONENT PARTS
Suction Valve 1, Suction Valve 2
Supplies the brake fluid from master cylinder to t
he pump, when VDC function and TCS function are activated.
Return Check Valve
Returns the brake fluid from brake caliper and wheel cy linder to master cylinder by bypassing orifice of each
valve when brake is released.
Reservoir
Temporarily reserves the brake fluid drained from brake caliper, so that pressure efficiently decreases when
decreasing pressure of brake caliper and wheel cylinder.
Yaw rate/side/decel G sensor
Calculates the following information that affects the vehicle, and transmits a signal to ABS actuator and elec-
tric unit (control unit) via communication lines.
• Vehicle rotation angular velocity (yaw rate signal)
• Vehicle lateral acceleration (side G signal) and longitudinal acceleration (decel G signal)
Pressure Sensor
Detects the brake fluid pressure and transmits signal to ABS actuator and electric unit (control unit).
Wheel Sensor and Sensor RotorINFOID:0000000009463744
NOTE:
• Wheel sensor of front wheel is installed on steering knuckle.
• Sensor rotor of front wheel is integrated in wheel hub assembly.
• Wheel sensor of rear wheel is installed on back plate of rear brake.
• Sensor rotor of rear wheel is installed on rear brake drum.
• Never measure resistance and voltage value using a tester because sensor is active sensor.
• Downsize and weight reduction is aimed. IC for detection portion and magnet for sensor rotor are adopted.
• Power supply is supplied to detection portion so that magnetic field line is read. Magnetic field that is detected is converted to current
signal.
• When sensor rotor rotates, magnetic field changes. Magnetic field change is converted to current signals (rectangular wave) and is
transmitted to ABS actuator and el ectric unit (control unit). Change
of magnetic field is proportional to wheel speed.
Stop Lamp SwitchINFOID:0000000009463745
Detects the operation status of brake pedal and transmits converted electric signal to ABS actuator and elec-
tric unit (control unit).
Steering Angle SensorINFOID:0000000009463746
Detects the following information and transmits steering angl e signal to ABS actuator and electric unit (control
unit) via CAN communication.
• Steering wheel rotation amount
• Steering wheel rotation angular velocity
• Steering wheel rotation direction
Brake Fluid Level SwitchINFOID:0000000009463747
Detects the brake fluid level in reservoir tank and transmi ts converted electric signal from combination meter to
ABS actuator and electric unit (control unit) via CAN communication.
Vacuum SensorINFOID:0000000009463748
Detects the vacuum in brake booster and transmits conver ted electric signal to ABS actuator and electric unit
(control unit).
JPFIC0131GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-12
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
SYSTEM
SYSTEM
VDC/TCS/ABS
VDC/TCS/ABS : System DiagramINFOID:0000000009463751
VDC/TCS/ABS : System DescriptionINFOID:0000000009463752
• The system switches fluid pressure of each brake caliper to increase, to hold, or to decrease according to
signals from control unit in ABS actuator and electric unit (control unit). This control system is applied to
VDC, TCS, ABS and EBD functions.
• Fail-safe function is available for each function and is activated by each function when system malfunction
occurs.
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
ALFIA0294GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMBRC-13
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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VALVE OPERATION (VDC AND TCS FUNCTIONS)
The control unit built in the ABS actuator and electric unit (control unit) controls fluid pressure of the brake cal-
ipers by operating each valve.
VDC and TCS Functions are Operating (Pressure Increases)
Component Signal description
Steering angle sensor Transmits the steering an
gle sensor signal to ABS actuator an d electric unit (control unit) via
CAN communication.
ECM Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Accelerator pedal position signal
• Engine speed signal
• Target throttle position signal
TCM Transmits the current gear positi
on signal to ABS actuator and electric unit (control unit) via
CAN communication.
Combination meter Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Brake fluid level switch signal
• Parking brake switch signal
Receives the foll owing signals from ABS actuator and elec tric unit (control unit) via CAN com-
munication.
• ABS warning lamp signal
• Brake warning lamp signal
• VDC OFF indicator lamp signal
• SLIP indicator lamp signal
ALFIA0309GB
Name Not activated 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 supp ly is not supplied (open) Power supp ly is not supplied (open)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-14
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
SYSTEM
Front RH brake caliper• Brake fluid is conveyed to the pump from the master
cylinder through suction valve 1 and is pressurized by
the pump operation. The pressurized brake fluid is s upplied to the front RH brake caliper through the ABS IN
valve. For the left caliper, brake fluid pressure is maintained because the pressurization is unnecessary. The
pressurization for the left caliper is controlled separately from the right caliper.
Front LH brake caliper
• Brake fluid is conveyed to the pump from the master cylinder through suction valve 2 and is pressurized by
the pump operation. The pressurized brake fluid is supp lied to the front LH brake caliper through the ABS IN
valve. For the right caliper, brake fluid pressure is maintained because the pressurization is unnecessary.
The pressurization for the right caliper is controlled separately from the left caliper.
Rear RH brake caliper
• Brake fluid is conveyed to the pump from the master cylinder through suction valve 2 and is pressurized by
the pump operation. The pressurized brake fluid is s upplied to the rear RH brake caliper through the ABS IN
valve. For the left caliper, brake fluid pressure is maintained because the pressurization is unnecessary. The
pressurization for the left caliper is controlled separately from the right caliper.
Rear LH brake caliper• Brake fluid is conveyed to the pump from the master cylinder through suction valve 1 and is pressurized by
the pump operation. The pressurized brake fluid is suppl ied to the rear LH brake caliper through the ABS IN
valve. For the right caliper, brake fluid pressure is maintained because the pressurization is unnecessary.
The pressurization for the right caliper is controlled separately from the left caliper.
VDC and TCS Functions Start Operating (Pressure Holds)
ABS OUT valve Power supply is not supplied (close) Power supply is not supplied (close)
Each brake caliper (fluid pressure) — Pressure increases Name Not activated Pressure increases
ALFIA0310GB
Name Not activated 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 not supplied (close)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMBRC-15
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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Front RH brake caliper• Since the cut valve 1 and the suction valve 1 are closed, the front RH brake caliper, master cylinder, and res- ervoir are blocked. This maintains fluid pressure applied on the front RH brake caliper. The pressurization for
the left caliper is controlled separately from the right caliper.
Front LH brake caliper
• Since the cut valve 2 and the suction valve 2 are clos ed, the front LH brake caliper, master cylinder, and res-
ervoir are blocked. This maintains fluid pressure app lied on the front LH brake caliper. The pressurization for
the right caliper is controlled separately from the left caliper.
Rear RH brake caliper
• Since the cut valve 2 and the suction valve 2 are clos ed, the rear RH brake caliper, master cylinder, and res-
ervoir are blocked. This maintains fluid pressure applied on the rear RH brake caliper. The pressurization for
the left caliper is controlled separately from the right caliper.
Rear LH brake caliper• Since the cut valve 1 and the suction valve 1 are closed, the rear LH brake caliper, master cylinder, and res- ervoir are blocked. This maintains fluid pressure app lied on the rear LH brake caliper. The pressurization for
the right caliper is controlled separately from the left caliper.
VDC and TCS Functions Operating (Pressure Decreases)
Suction valve 2 Power supply is not supplied (close) Power supply is not supplied (close)
ABS IN valve Power supp ly is not supplied (open) Power supp ly is not supplied (open)
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each brake caliper (fluid pressure) — Pressure holds Name Not activated Pressure holds
ALFIA0311GB
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)
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-16
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
SYSTEM
Front RH brake caliper• Since the suction valve 1 and the ABS OUT valve are closed and the cut valve 1 and the ABS IN valve are
open, the fluid pressure applied on the front RH brake ca liper is reduced by supplying the fluid pressure to
the master cylinder via the ABS IN valve and the cut valv e 1. The pressurization for the right caliper is con-
trolled separately from the left caliper.
Front LH brake caliper
• Since the suction valve 2 and the ABS OUT valve are closed and the cut valve 2 and the ABS IN valve are open, the fluid pressure applied on the front LH brake caliper is reduced by supplying the fluid pressure to
the master cylinder via the ABS IN valve and the cut valv e 2. The pressurization for the left caliper is con-
trolled separately from the right caliper.
Rear RH brake caliper
• Since the suction valve 2 and the ABS OUT valve are closed and the cut valve 2 and the ABS IN valve are open, the fluid pressure applied on the rear RH brake ca liper is reduced by supplying the fluid pressure to
the master cylinder via the ABS IN valve and the cut valv e 2. The pressurization for the right caliper is con-
trolled separately from the left caliper.
Rear LH brake caliper• Since the suction valve 1 and the ABS OUT valve are closed and the cut valve 1 and the ABS IN valve are open, the fluid pressure applied on the rear LH brake cali per is reduced by supplying the fluid pressure to the
master cylinder via the ABS IN valve and the cut valve 1. The pressurization for the left caliper is controlled
separately from the right caliper.
Component Parts and Function
VALVE OPERATION (ABS AND EBD FUNCTIONS)
The control unit built into the ABS act uator and electric unit (control unit) controls fluid pressure of the brake
calipers by operating each valve.
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 Name Not activated During pressure decreases
Component Function
Pump Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.
Motor Activates the pu mp according to signals from ABS actuator and el ectric 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 to signals from control unit.
ABS OUT valve Switches the fluid pressure li ne to increase, hold or decrease according to si gnals 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.
Reservoir Temporarily reserves the brake fluid drained from brake caliper, so that pressure efficiently decreas-
es when decreasing pressure of brake caliper.
Pressure sensor Detects the brak e fluid pressure and transmits signal to ABS actuator and electric unit (control unit).
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMBRC-17
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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Brake Pedal Applied or ABS Function
Operating (Pressure Increases)
Front RH brake caliper
• When the cut valve 1 and the ABS IN valve opens, brake fluid is supplied to the front RH brake caliper from
the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS
OUT valve is closed.
Front LH brake caliper• When the cut valve 2 and the ABS IN valve opens, brake fl uid is supplied to the front LH brake caliper from
the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS
OUT valve is closed.
Rear RH brake caliper• When the cut valve 2 and the ABS IN valve opens, brake fluid is supplied to the rear RH brake caliper from the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS
OUT valve is closed.
Rear LH brake caliper
• When the cut valve 1 and the ABS IN valve opens, brake fl uid is supplied to the rear LH brake caliper from
the master cylinder through the ABS IN valve. Brake fluid does not flow into the reservoir because the ABS
OUT valve is closed.
ALFIA0312GB
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 supp ly is not supplied (open) Power supp ly is not supplied (open)
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each brake caliper (fluid pressure) — Pressure increases
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM