Brake Control System: Overview Nissan Maxima A35

ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Description

After replacing the ABS actuator and electric unit (control unit), perform the neutral position adjustment for the steering angle sensor.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Description

When performing work that applies to the list below, make sure to adjust neutral position of steering angle sensor before operating vehicle.

STEERING ANGLE SENSOR NEUTRAL POSITION ADJUSTMENT REFERENCE CHART

System Description

1. Vehicle dynamic control system detects driver's steering operation amount from the steering angle sensor. Using input information from the yaw rate/side/decel G sensor and wheel speed sensors, the VDC system judges driving conditions (conditions of understeer and oversteer) and controls engine output and brake application to improve vehicle driving stability.
2. During VDC operation, it informs driver of system operation by flashing SLIP indicator lamp.
3. Electrical system diagnosis by CONSULT-III is available.

Scheme 1

Component Description

COMPONENTS REFERENCE CHART

1. Traction Control System is a function that electronically controls engine torque and brake fluid pressure to ensure the optimum slippage ratio at drive wheels by computing wheel speed signals from 4 wheel sensors. When ABS actuator and electric unit (control unit) detects a spin at drive wheels, it compares wheel speed signals from all 4 wheels. At this time, LH and RH front brake fluid pressure are controlled, while fuel being cut to engine and throttle valve being closed to reduce engine torque by the control unit. Further more, throttle position is continuously controlled to ensure the optimum engine torque at all times.
2. During TCS operation, it informs driver of system operation by flashing slip indicator lamp.
3. Electrical system diagnosis by CONSULT-III is available.

Scheme 2

COMPONENTS REFERENCE CHART

1. Anti-Lock Braking System is a function that detects wheel revolution while braking, electronically controls braking force, and prevents wheel locking during sudden braking. It improves handling stability and maneuverability for avoiding obstacles.
2. Electrical system diagnosis by CONSULT-III is available.

Scheme 3

COMPONENTS REFERENCE CHART

Electric Brake force Distribution functions as follows

1. ABS actuator and electric unit (control unit) detects subtle slippages between the front and rear wheels during braking. Then it electronically controls the rear braking force (brake fluid pressure) to reduce rear wheel slippage. Accordingly, it improves vehicle stability.
2. Electrical system diagnosis by CONSULT-III is available.

Scheme 4

COMPONENTS REFERENCE CHART

Operation Procedure

Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute.

Description

When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).

When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).

Supplies electric power to the ABS actuator and electric unit (control unit).

Activates or deactivates each solenoid valve according to the signals transmitted by the ABS actuator and electric unit (control unit).

When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).

The stop lamp switch transmits the stop lamp switch signal (ON/OFF) to the ABS actuator and electric unit (control unit).

The solenoid valve increases, holds or decreases the fluid pressure of each brake caliper according to the signals transmitted by the ABS actuator and electric unit (control unit).

The solenoid valve increases, holds or decreases the fluid pressure of each brake caliper according to the signals transmitted by the ABS actuator and electric unit (control unit).

ABS actuator and electric unit (control unit) and ECM exchange the engine signal with CAN communication line.

The pressure sensor converts the brake fluid pressure to an electric signal and transmits it to the ABS actuator and electric unit (control unit). (The pressure sensor is integrated in the ABS actuator and electric unit (control unit).)

The steering angle sensor detects the rotation amount, angular velocity and direction of the steering wheel, and transmits the data to the ABS actuator and electric unit (control unit) via CAN communication.

The yaw rate/side/decel G sensor detects the yaw rate/side/decel G affecting the vehicle, and transmits the data to the ABS actuator and electric unit (control unit) as an analog voltage signal.

The transmission range switch signal is transmitted to the ABS actuator and electric unit (control unit) using the CAN communication lines.

The brake fluid level switch converts the brake fluid level to an electric signal and transmits it to the ABS actuator and electric unit (control unit).

The steering angle sensor is connected to the ABS actuator and electric unit (control unit) in addition to CAN lines. CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

The parking brake switch converts the status of the parking brake pedal to an electric signal and transmits it to the combination meter. The combination meter, through CAN communication, transmits the signal to the ABS actuator and electric unit (control unit).

VDC OFF switch deactivates (turn OFF) the VDC/TCS function when the VDC OFF switch is pressed.

ABS WARNING LAMP REFERENCE CHART

BRAKE WARNING LAMP OPERATION REFERENCE CHART

VDC OFF INDICATOR LAMP OPERATION REFERENCE CHART

SLIP INDICATOR LAMP OPERATION REFERENCE CHART

See also:
• CONSULT-III FUNCTION