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Nissan Quest E52. Manual - part 233

SYSTEM

BRC-25

< SYSTEM DESCRIPTION >

[WITH VDC]

BRC

*: Communication line between yaw rate/side G sensor and ABS actuator and electric unit (control unit)

ABS FUNCTION

ABS FUNCTION : System Description

INFOID:0000000009651362

• By preventing wheel lock through brake force (brake fluid pressure) control that is electronically controlled by

detecting wheel speed during braking, stability during emergency braking is improved so that obstacles can
be easily bypassed by steering operation.

• During braking, control units calculates wheel speed and pseudo-vehicle speed, and transmits pressure

increase, hold or decrease signals to actuator portion according to wheel slip status.

Component

Signal description

Yaw rate/side G sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via com-

munication line

• Yaw rate signal
• Side G sensor signal

ECM

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Acceleration pedal position signal
• Engine speed signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
• Target throttle position signal

TCM

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Shift position signal
• Current gear position signal
• P range signal
• R range signal
• N range signal

Steering angle sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Steering angle sensor signal

Combination meter

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Brake fluid level switch signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
• VDC warning lamp signal
• VDC OFF indicator lamp signal

BRC-26

< SYSTEM DESCRIPTION >

[WITH VDC]

SYSTEM

• The following effects are obtained by preventing wheel lock during

braking.

- Vehicle tail slip is prevented during braking when driving straight.
- Understeer and oversteer tendencies are moderated during brak-

ing driving on a corner.

- Obstacles may be easily bypassed by steering operation during

braking.

• CONSULT can be used to diagnose the system diagnosis.
• Fail-safe function is adopted. When a malfunction occurs in ABS

function, the control is suspended for VDC function, TCS function,
ABS function and brake limited slip differential (BLSD) function.
The vehicle status becomes the same as models without VDC
function, TCS function, ABS function and brake limited slip differ-
ential (BLSD) function. However, EBD function is operated nor-
mally. Refer to

BRC-20, "Fail-safe"

NOTE:
• ABS has the characteristic as described here, but it is not the

device that helps reckless driving.

• To stop vehicle efficiently, ABS does not operate and ordinary

brake operates at low speed [approx. 10 km/h (6.2 MPH) or less,
but differs subject to road conditions).

• Self-diagnosis is performed immediately after when engine starts

and when vehicle initially is driven [by vehicle speed approx. 15
km/h (9.3 MPH)]. Motor sounds are generated during self-diagno-
sis. In addition, brake pedal may be felt heavy when depressing brake pedal lightly. These symptoms are not
malfunctions.

SYSTEM DIAGRAM

INPUT SIGNAL AND OUTPUT SIGNAL

Major signal transmission between each unit via communication lines is shown in the following table.

JPFIC0140GB

JSFIA0973GB

SYSTEM

BRC-27

< SYSTEM DESCRIPTION >

[WITH VDC]

BRC

*: Communication line between yaw rate/side G sensor and ABS actuator and electric unit (control unit)

EBD FUNCTION

EBD FUNCTION : System Description

INFOID:0000000009651363

• By preventing rear wheel slip increase through rear wheel brake force (brake fluid pressure) control that is

electronically controlled when slight skip on front and rear wheels are detected during braking, stability dur-
ing braking is improved.

• EBD function is expanded and developed from conventional ABS function and corrects rear wheel brake

force to appropriate level by electronic control according to load weight (number of passengers).

• During braking, control unit portion compares slight slip on front

and rear wheels by wheel speed sensor signal, transmits drive sig-
nal to actuator portion when rear wheel slip exceeds front wheel
slip for the specified value or more, and controls rear wheel brake
force (brake fluid pressure) so that increase of rear wheel slip is
prevented and slips on front wheel and rear wheel are nearly
equalized. ABS control is applied when slip on each wheel
increases and wheel speed is the threshold value of ABS control or
less.

• CONSULT can be used to diagnose the system diagnosis.
• Fail-safe function is adopted. When a malfunction occurs in EBD

function, the control is suspended for VDC function, TCS function,
ABS function, EBD function and brake limited slip differential
(BLSD) function. The vehicle status becomes the same as models
without VDC function, TCS function, ABS function, EBD function
and brake limited slip differential (BLSD) function. Refer to

BRC-

20, "Fail-safe"

Component

Signal description

Yaw rate/side G sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via com-

munication line

• Yaw rate signal
• Side G sensor signal

Steering angle sensor

Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Steering angle sensor signal

Combination meter

Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
• VDC warning lamp signal
• ABS warning lamp signal

JPFIC0142GB

JPFIC0143GB

BRC-28

< SYSTEM DESCRIPTION >

[WITH VDC]

SYSTEM

SYSTEM DIAGRAM

INPUT SIGNAL AND OUTPUT SIGNAL

Major signal transmission between each unit via communication lines is shown in the following table.

BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION

BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION : System Description

INFOID:0000000009651364

• LH and RH driving wheel spin is always monitored. If necessary, appropriate brake force is independently

applied to LH or RH driving wheel so that one-sided wheel spin is avoided and traction is maintained. Mainly
starting ability is improved.

• Brake limited slip differential (BLSD) function operates while VDC function is in non-operational status (OFF)

by VDC OFF switch.

• VDC warning lamp blinking while brake limited slip differential (BLSD) function is in operation and indicates

to the driver that the function is in operation.

• Slight vibrations are felt on the brake pedal and the operation noises occur, when brake limited slip differen-

tial (BLSD) function operates. This is not a malfunction because it is caused by brake limited slip differential
(BLSD) function that is normally operated.

• CONSULT can be used to diagnose the system diagnosis.
• Fail-safe function is adopted. When a malfunction occurs in brake limited slip differential (BLSD) function,

the control is suspended for VDC function, TCS function and brake limited slip differential (BLSD) function.
The vehicle status becomes the same as models without VDC function, TCS function and brake limited slip
differential (BLSD) function. However, ABS function and EBD function are operated normally. Refer to

BRC-

20, "Fail-safe"

JPFIC0144GB

Component

Signal description

Combination meter

Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
• VDC warning lamp signal
• ABS warning lamp signal
• Brake warning lamp signal

Content .. 231 232 233 234 ..