ELECTRIC PARKING BRAKE SYSTEM SYSTEM DESCRIPTION

SYSTEM DESCRIPTION

The electric parking brake system controls the parking brake cable by electrically loosening and tightening the cable with the actuator. The main functions are as follows.

• The parking brake lock/release control is performed by manually operating the electric parking brake switch.

• When the AUTO switch (parking light switch assembly) is ON, the parking brake lock/release control operates according to the shift lever position. (Moved from position other than P to P position: lock; move from P to position other than P: release.)

1. The standard parking brake lock/release controls (while vehicle is stopped) are as follows.

   
   

   1. The lock control will tighten the parking brake cable to increase tension. The tension will be increased to the target value based on the tilt of the vehicle according to the yaw rate sensor. If the cable tension reaches the target value, the lock control stops tightening the cable and maintains this cable tension.

   2. The release control loosens the cable until the parking brake cable tension reaches a specified value.

   3. When the driver side door is opened or the driver seat belt is unfastened while the brake hold is operating (vehicle is stopped), or 3 minutes elapse after brake hold operates, the parking brake automatically locks.

      When the brake pedal is depressed during the above conditions, the parking brake does not automatically lock.

      When starting off, it is necessary to either perform a release operation with the electric parking brake switch assembly or depress the accelerator pedal to release the parking brake.

      Tech Tips

      When the brake system malfunctions while brake hold is operating, the parking brake automatically locks.

      When starting off, it is necessary to perform a release operation with the electric parking brake switch to release the parking brake.

2. While the vehicle is being driven, the lock control only operates while the electric parking brake switch assembly is being pushed. The release control operates immediately after the switch is released.

COMPONENTS OPERATION

1. Parking brake ECU assembly

   
   

   1. The parking brake ECU assembly operates the parking brake actuator to lock or release the parking brake according to the shift lever position, signals and conditions through CAN communication, and switch operations from the driver.

2. Parking brake with bracket actuator assembly

   
   

   1. The parking brake with bracket actuator assembly controls the parking brake by tightening and loosening the parking brake cable according to signals from the parking brake ECU assembly.

3. Tension sensor

   
   

   1. The tension sensor is built into the parking brake with bracket actuator assembly and outputs the tension value of the parking brake cable to the parking brake ECU assembly.

4. Electric parking brake switch assembly

   
   

   1. Lock switch

      
      

      • Detects the lock operation from the driver, and outputs a signal to the parking brake ECU assembly.

   2. Release switch

      
      

      • Detects the release operation from the driver, and outputs a signal to the parking brake ECU assembly.

   3. AUTO switch (Parking light switch assembly)

      
      

      • Detects an AUTO function ON/OFF change from the driver, and outputs a signal to the parking brake ECU assembly.

   4. AUTO indicator light

      
      

      • The AUTO indicator light informs the driver if the shift-linked function is possible or not.

   5. Brake warning light / yellow (minor malfunction)

      
      

      • The brake warning light / yellow (minor malfunction) is used by the parking brake ECU assembly and skid control ECU assembly. If the electric parking brake system is malfunctioning or a problem in another system causes the parking brake function to be limited, this light informs the driver. This light also illuminates for 3 seconds after the engine switch is turned on (IG).

   6. Parking brake indicator light (red)

      
      

      • When the parking brake is locked, the parking brake indicator light (red) illuminates. Also, if the driver attempts to operate the electric parking brake when operation is not possible, the light blinks. The light also blinks when the cable loosens due to an outside influence.

   7. Multi-information display

      
      

      • If a malfunction occurs in the electric parking brake system and the system control is not possible, the brake warning light / yellow (minor malfunction) and multi-information display are used to inform the driver. The multi-information display is also used to display cautions.