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Outline

Functions

Electric parking brake apply/release

• Controls the apply/release of the electric parking brake based on the input signal from the electric parking brake switch.

Electric parking brake automatic release function

• Releases the electric parking brake automatically when the vehicle starts from a standstill.

Emergency braking function

• The function generates braking force by pulling up the electric parking brake switch while the vehicle is driven.

• When the electric parking brake switch is pulled up while the vehicle is driven, the DSC HU/CM pressurizes the brake fluid to generate braking force. If a malfunction occurs in the DSC system and the brake fluid cannot be pressurized, the electric parking brake operates to generate braking force.

Electric parking brake automatic operation function

• The function operates the electric parking brake automatically.

Electric parking brake automatic operation function (during AUTOHOLD operation)

• The electric parking brake operates automatically based on the DSC HU/CM request during AUTOHOLD operation.

Note

• The electric parking brake automatic release function is used to release the electric parking brake during AUTOHOLD operation.

Electric parking brake display function

• The DSC HU/CM notifies the driver of the system conditions using an electric parking brake indicator light, electric parking brake chime, center display , and multi-information display .

Note

• A warning message in the center display is displayed when the brake control system warning light/electric parking brake indicator light turns on or flashes. For the message content and verification method, refer to the [CENTER DISPLAY] in the workshop manual.

Maintenance mode

• By switching to the maintenance mode when replacing the rear disc pads or rear disc plates, the electric parking brake motor gear unit motor will operate to allow the brake pistons to be pressed in. For details on the method for switching to the maintenance mode, refer to the [MAINTENANCE MODE].

Electric parking brake inspection mode

• The electric parking brake inspection mode is a function that prevents the vehicle from suddenly flying off the brake tester by gradually strengthening the clamp power of the parking brake when the rear wheel speed is between 3 km/h {2 mph} and 12 km/h {7.5 mph} for a continuous 3 s or more while using a brake tester with rollers that have a fast rotation speed. When all the operation conditions are met, the normal mode switches to the electric parking brake inspection mode automatically. In addition, normal electric parking brake control is performed when using a brake tester with a rear wheel speed of less than 3 km/h {2 mph}. For details on the operation conditions and the control content, refer to the [SERVICE CAUTIONS] in the Workshop Manual.

Automatic configuration function

• When the ignition is switched ON after the DSC HU/CM has been replaced, the DSC HU/CM reads the data from the instrument cluster via CAN communication and performs the configuration.

Construction

Structure

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System wiring diagram

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Block diagram

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Operation

Electric parking brake operation

• The electric parking brake operates when the following operation conditions are met.

Operation condition

― Pull up the electric parking brake switch.

― The vehicle is stopped.

1.When the electric parking brake switch is pulled up, the DSC HU/CM detects an electric parking brake operation request signal (1).

2.When the DSC HU/CM detects the electric parking brake operation request signal, it outputs motor operation current (2) to the electric parking brake motor gear unit.

3.The motor operates (3) by the motor operation current. (The motor rotates towards the engagement side)

4.The electric parking brake operates, and the operations stops when the motor reaches the target current.

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Note

Electric parking brake motor gear unit control contents (when operating electric parking brake)

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Electric parking brake release

• The electric parking brake is released when the electric parking brake switch is pressed with the following operation conditions met.

Operation condition

― Ignition switch ON (engine off or on)

― Brake pedal is being operated, or accelerator pedal is being operated.

1.When the electric parking brake switch is pressed, the DSC HU/CM detects an electric parking brake release request signal (1).

2.The DSC HU/CM outputs the motor operation current (2) to the electric parking brake motor gear unit.

3.The motor operates (3) by the motor operation current. (The motor rotates in the opposite direction of the engagement side)

4.The electric parking brake is released and when the motor reaches the target stroke, the operation stops.

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Note

Electric parking brake motor gear unit control contents (when releasing electric parking brake)

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Electric parking brake automatic release function

• The electric parking brake automatic release function operates when the accelerator pedal is depressed with all of the following conditions met.

Operation condition

― Ignition is switched ON (engine on)

― Driver’s door closed

― Driver seat belt fastened

― Selector lever is in position other than N and P (ATX)

― Shift lever is in position other than N (MTX)

― Clutch pedal is depressed (MTX)

1.The electric parking brake automatic release function activates and motor operation current (3) flows to the electric parking brake motor gear unit when the DSC HU/CM receives a signal (1) from the PCM indicating that the accelerator pedal is depressed and a signal (2) indicating that the drive toque necessary for acceleration exceeds the specification.

2.The motor operates (4) by the motor operation current. (The motor rotates in the opposite direction of the engagement side)

3.The electric parking brake is released and when the motor reaches the target stroke, the operation stops.

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Emergency braking function

Note

• The emergency braking function operates only when the electric parking brake switch is continuously pulled up while the vehicle is being driven.

• The emergency brake function operates when all of the following conditions are met.

Operation condition

― Vehicle is being driven

― Electric parking brake switch is continuously pulled up

No malfunction in DSC system

1. When the DSC HU/CM detects an electric parking brake operation request signal (1) of the electric parking brake switch while the vehicle is being driven, The DSC HU/CM pressurizes the brake fluid.

2. The brake fluid pressure is transmitted to the front brakes and rear brakes to generate braking force.

Malfunction in DSC system

1. When the DSC HU/CM detects an electric parking brake operation request signal (1) of the electric parking brake switch while the vehicle is being driven, it sends motor operation current (2) to the electric parking brake motor gear unit.

2. The motor operates (3) and generates braking force by the motor operation current. (The motor rotates towards the engagement side)

Note

• For vehicle speeds of 5 km/h {3 mph} or more, independent anti-lock control on the left and right is performed so that the rear wheels do not lock-up.

• When the vehicle speed is 3 km/h {2 mph} or less, the emergency braking function does not operate so that the system can determine if the vehicle is about to stop.

• If the ABS control is detected while the emergency braking function is operating, control of the emergency braking function is canceled.

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Electric parking brake automatic operation function (during AUTOHOLD operation)

• The electric parking brake automatic operation function operates when all of the following conditions are met.

Operation condition

― During AUTOHOLD operation (See AUTOHOLD [(US)].)

1.When AUTOHOLD operates, the DSC HU/CM sends a motor operation current (1) to the EPB motor gear unit.

2.The motor operates (2) by the motor operation current. (The motor rotates towards the engagement side)

3.The electric parking brake operates, and the operations stops when the motor reaches the target current.

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Electric parking brake automatic operation function

• The electric parking brake automatic operation function operates when all of the following conditions are met.

Operation conditions

― Ignition is switched OFF

― The vehicle is stopped

1.When all of the operation conditions of the electric parking brake automatic operation function are met, the electric parking brake automatic operation function operates and the DSC HU/CM sends motor operation current (1) to the electric parking brake motor gear unit.

2.The motor operates (2) by the motor operation current. (The motor rotates towards the engagement side)

3.The electric parking brake operates, and the operation stops when the motor reaches the target current.

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Electric parking brake display function

• The instrument cluster displays as indicated in the table below when the vehicle is under the following conditions.

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Electric parking brake display table

Condition	Electric parking brake indicator light	Brake control system warning light	Multi-information display	Electric parking brake chime
The electric parking brake is operating while the vehicle is stopped.	On	Off	No display	Off
Electric parking brake is released.	Off	Off	No display	Off
The electric parking brake switch is pressed without depressing the brake pedal while the vehicle is stopped.	On	Off		Off
The electric parking brake automatic release function operates during acceleration.	Off	Off	No display	Off
The accelerator pedal is depressed when the electric parking brake is operating while the vehicle is stopped (door opened or driver seat belt unfastened)	On	Off		on *1
The electric parking brake is operated while the vehicle is driven.				On
The electric parking brake switch is operated (pulled/pressed) while the EPB system is malfunctioning.	Flash	On		Off
There is a malfunction in the parking brake force of the electric parking brake.
No malfunction in parking brake force, but malfunction occurring in electric parking brake system	Off *2 or on *3
The mode is switched to the maintenance mode.	Off		No display
The mode is switched to the electric parking brake inspection mode.	Off *2 or on *3
The electric parking brake cannot be operated because there is a malfunction in the electric parking brake system while the vehicle is stopped.	Off *2 or on *3	On		Off