System Description

Automatic brake hold is used for holding the brakes automatically when the vehicle is stopped by a brake operation.
Automatic brake hold is used to reduce continuous brake pedal operations by the driver.
Automatic brake hold is controlled by chassis control module.
Chassis control module receives information required for controlling via CAN communication and from each switch to control automatic brake hold.

SYSTEM DIAGRAM

Component	Signal description
ECM	Mainly transmits the following signals to chassis control module via CAN communication. Accelerator pedal position signal Engine torque signal
TCM	Mainly transmits the following signals to chassis control module via CAN communication. Current gear position signal
ABS actuator and electric unit (control unit)	Mainly transmits the following signals to chassis control module via CAN communication. Brake hold status signal Brake fluid pressure signal Electric parking brake operation signal (switch) Electric parking brake status signal Front LH wheel speed signal Front RH wheel speed signal Rear LH wheel speed signal Rear RH wheel speed signal ASC malfunction signal Decel G signal Electric parking brake malfunction signal
Combination meter	Mainly receives the following signals from chassis control module via CAN communication. Automatic brake hold indicator light signal Meter display signal
BCM	Mainly transmits the following signals to chassis control module via CAN communication. Brake pedal status signal Seat belt buckle switch (driver side) signal
Chassis control module	Chassis Control Module
Parking brake switch (automatic brake hold switch)	Parking Brake Switch (Automatic Brake Hold Switch)

OPERATION

Automatic Brake Hold Function ON (Operation Permitted)

If automatic brake hold switch is pressed when ignition switch is ON, automatic brake hold function turns ON. In addition, automatic brake hold switch indicator illuminates.

note	The automatic brake hold function resets to OFF every time the ignition switch is switched from ON to OFF.

Automatic Brake Hold Function OFF (Operation Not Permitted)

If automatic brake hold switch is pressed when automatic brake hold function is ON, automatic brake hold function turns OFF. In addition, automatic brake hold switch indicator turns OFF. [If automatic brake hold indicator light (white or green) is ON, it turns OFF.]

note	To turn OFF automatic brake hold function while the brakes are held by automatic brake hold, press automatic brake hold switch while depressing brake pedal.

Standby

When all of the following conditions are satisfied, automatic brake hold enters in the standby state, and automatic brake hold indicator light (white) illuminates.

Seat belt (driver side) is fastened
Parking brake release
Electric shift selector is other than P range.

Operation

If all of the following conditions are satisfied in the standby state, automatic brake hold operates, and the color of automatic brake hold indicator light changes from white to green. In addition, automatic brake display appears on information display of combination meter.

note	Although the conditions are satisfied in the standby state, automatic brake hold may not operate depending on how far brake pedal is depressed. When automatic brake hold does not operate, depress brake pedal far enough until automatic brake hold indicator light (green) turns on.

Vehicle speed: 0 km/h (0 MPH)
Brake pedal is depressed
Automatic brake hold is in the standby state [automatic brake hold switch indicator and automatic brake hold indicator light (white) are illuminated]
Not on a steep slope
Seat belt (driver side) is fastened
Parking brake release
Electric shift selector is other than P range.

Release (Starting Vehicle)

If the following condition is satisfied while automatic brake hold is being applied, automatic brake hold is released. (The color of automatic brake hold indicator light changes from green to white.)

note	When depressing accelerator pedal at except P range and N range just before moving the vehicle.

Release (Changing to Parking Brake)

If any of the following conditions are met while automatic brake hold is being applied, parking brake is operated automatically, and automatic brake hold is released. (Automatic brake hold indicator light turns OFF.)

Operation of automatic brake hold is continued for approximately 3 minutes
Seat belt (driver side) is unfastened
Ignition switch OFF
A malfunction is detected in automatic brake hold
Electric shift selector is P range

Parking

If shifting the electric shift selector to P range while automatic brake hold is being applied, automatic brake hold is released. (Automatic brake hold indicator light turns OFF.)

Timing Chart

The vehicle is started while automatic brake hold is being applied

	When the vehicle is stopped by a brake operation by the driver, maintaining of brake fluid pressure is started.
	Automatic brake hold is applied (this function holds brake fluid pressure even after the driver has released brake pedal).
	When the driver performs starting operation, automatic brake hold is released (brake fluid pressure is decreased).

Changing the vehicle holding method to parking brake while automatic brake hold is being applied

	When the vehicle is stopped by a brake operation by the driver, maintaining of the brake fluid pressure is started.
	Automatic brake hold is applied (this function holds brake fluid pressure even after the driver has released brake pedal).
	If the conditions for changing to parking brake are satisfied while automatic brake hold is being applied, the method of holding the vehicle stopped is automatically changed to parking brake.