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Nissan Leaf. Manual - part 175

SYSTEM

BR-21

< SYSTEM DESCRIPTION >

The stroke sensor detects the brake pedal stroke, and the motor inside the electrically-driven intelligent brake

unit presses the master cylinder piston, generating boost operation (brake pedal assist force) and increasing

the fluid pressure.

When Cooperative Regenerative Brake Control Is Operating

Motor

Piston

JSFIA1647ZZ

JSFIA1648ZZ

BR-22

< SYSTEM DESCRIPTION >

SYSTEM

When the amount of regenerative braking increases, the motor inside the electrically-driven intelligent brake

unit returns the master cylinder piston, lowering the fluid pressure. While the vehicle is stopped, because the

amount of regenerative braking decreases, the motor inside the electrically-driven intelligent brake unit

presses the master cylinder piston, increasing the fluid pressure.

When Control Is Stopped

The input rod crosses the cooperative regenerative brake control gap and contacts the master cylinder piston,

generating fluid pressure. There is no boost force (assist force), and the braking force is determined by the

force pressing on the brake pedal.

hill start assist FUNCTION
hill start assist FUNCTION : System Description

INFOID:0000000010122989

• This function maintains brake fluid pressure so that the vehicle does not move backwards even if brake

pedal is released to depress accelerator pedal to start the vehicle while it is stopped on an uphill slope by

depressing brake pedal.

• This function operates when the vehicle is in stop status on a uphill slope of slope ratio 10% or more and

selector lever is in the position other than P or N.

• hill start assist function is only for the start aid. It maintains the brake fluid pressure for approx. 2 seconds

after releasing the brake pedal, and then decreases the pressure gradually. If the vehicle can start by the

accelerator operation, the brake is released automatically and a smooth start can be performed.

• Fail-safe function is adopted. When a malfunction occurs in hill start assist function, the control is suspended

for hill start assist function. The vehicle status becomes the same as models without hill start assist function.

Refer to

BR-16, "Fail-Safe"

SYSTEM DIAGRAM

Motor

Piston

Motor

Piston

Input rod

JSFIA1649ZZ

SYSTEM

BR-23

< SYSTEM DESCRIPTION >

INPUT SIGNAL AND OUTPUT SIGNAL

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

JSFIA2283GB

Component

Signal description

ABS actuator and electric unit (control unit)

Mainly transmits the following signals to electrically-driven intelligent brake unit via CAN
communication and brake communication (CAN communication).
• ABS actuator and electric unit (control unit) control signal
• Vehicle speed signal (ABS)
• Decel G signal
• Front LH wheel speed signal
• Rear LH wheel speed signal
• Front RH wheel speed signal
• Rear RH wheel speed signal
• Yaw rate signal
• Side G signal
• VDC malfunction signal
• VDC OFF switch signal
• Master cylinder fluid pressure signal
Mainly receives the following signals from electrically-driven intelligent brake unit via CAN
communication and brake communication (CAN communication).
• Electrically-driven intelligent brake control signal
• Brake assist request signal
• Brake power supply backup operation signal
• Brake power supply backup operation request signal
• Brake warning lamp request signal
• Brake system warning lamp request signal

VCM

Mainly transmits the following signals to electrically-driven intelligent brake unit via CAN
communication.
• VCM control signal
• Current regenerative torque signal
• VCM status signal
• Shift position signal
Mainly receives the following signal from electrically-driven intelligent brake unit via CAN
communication.
• Target braking force signal

BR-24

< SYSTEM DESCRIPTION >

SYSTEM

WARNING/INDICATOR/CHIME LIST
WARNING/INDICATOR/CHIME LIST : Warning Lamp/Indicator Lamp

INFOID:0000000010122990

FOR U.S.A.

FOR CANADA

WARNING/INDICATOR/CHIME LIST : Brake System Warning Lamp (Yellow)

INFOID:0000000010122991

DESIGN/PURPOSE

• The brake system warning lamp warns the driver of a malfunction in the electrically-driven intelligent brake

unit or the brake power supply backup unit.

- For U.S.A.

BCM

Mainly transmits the following signals to electrically-driven intelligent brake unit via CAN
communication.
• Sleep wake up signal
• Power switch ON signal
• Door switch signal

Steering angle sensor

Mainly transmits the following signal to electrically-driven intelligent brake unit via CAN
communication.
• Steering angle sensor signal

Combination meter

Mainly receives the following signals from ABS actuator electric unit (control unit) via elec-
trically-driven intelligent brake unit via CAN communication.
• Brake warning lamp signal
• Brake system warning lamp signal

Component

Signal description

Name

Design

Layout/Function

Brake system warning lamp
(yellow)

For layout: Refer to

MWI-8, "METER SYSTEM : System Description"

For function: Refer to

BR-24, "WARNING/INDICATOR/CHIME LIST : Brake System

Warning Lamp (Yellow)"

Brake warning lamp
(red)