SMART BRAKE SUPPORT (SBS) [FORWARD DETECTION]
id151000015500
Outline
• With the smart brake support (SBS) [forward detection] system, the front radar sensor and the forward sensing camera (FSC) detect a vehicle ahead, pedestrians, or bicycles, and if they determine that there is the possibility of a collision, the driver is alerted by the smart brake support (SBS) warning indication, the warning indications on the active driving display and the multi-information display, and a warning sound is activated intermittently.
• Then, if avoidance maneuvers cannot be performed and the danger of a collision increases, the system operates the brakes to reduce the damage from the collision.
• The smart brake support (SBS) [forward detection] shares most of the system components with the Mazda radar cruise control (MRCC). For details on the Mazda radar cruise control (MRCC) system, refer to [MAZDA RADAR CRUISE CONTROL WITH STOP & GO FUNCTION (MRCC WITH STOP & GO FUNCTION)].
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Warning
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• The smart brake support (SBS) [forward detection] operates when certain conditions are met, however, it is not a system that assures prevention of a collision. There are limitations to the deceleration ability by the brake control (damage reduction braking), and the system may be unable to decelerate sufficiently to avoid hitting the vehicle ahead if the vehicle ahead applies the brakes suddenly or another vehicle cuts into the driving lane, which could result in an accident. Always verify the safety of the surrounding area and keep a safe distance a vehicle ahead, pedestrians or bicycles.
• Operation on vehicle ahead
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― If vehicle speed is approx. 4km/h {2.5mph} or less, smart brake support (SBS) [forward detection] does not operate
• Operation on pedestrians or bicycles:
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― If vehicle speed is approx. 10km/h {6.2mph} or less, smart brake support (SBS) [forward detection] does not operate
― If vehicle speed is approx. 80km/h {50mph} or less, smart brake support (SBS) [forward detection] does not operate
• The smart brake support (SBS) [forward detection] recognizes a vehicle ahead, pedestrians, or bicycles. It does not recognize obstructions such as walls and animals.
• Do not apply stickers to the area around the forward sensing camera (FSC) on the windshield. Application of even transparent stickers will cause the smart brake support (SBS) [forward detection] to operate incorrectly, which could result in an accident.
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Caution
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• Tires for all four wheels must always be of the specified type and size. If tires other than the specified type and size are used, the smart brake support (SBS) [forward detection] may not operate normally.
• Do not mix tire types or use tires with significantly different wear patterns on the same vehicle. Use of inappropriate tires could result in the smart brake support (SBS) [forward detection] not operating normally.
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Note
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• The smart brake support (SBS) [forward detection] is designed to assist the driver. The driver's driving operation always takes priority even while the smart brake support (SBS) [forward detection] is operating. For this reason, if the driver depresses the accelerator pedal suddenly to avoid danger, the smart brake support (SBS) [forward detection] operation is canceled temporarily.
• In the following cases, turn off the smart brake support (SBS) [forward detection] using the personalization features to prevent incorrect operation of the smart brake support (SBS) [forward detection].
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― Vehicle is to tow another vehicle or be towed
― Chassis dynamometer is used
― Vehicle is traveling over grassy areas or off-road
• If the vehicle is stopped by the operation of the smart brake support (SBS) [forward detection],the smart brake support (SBS) [forward detection] maintains the brakes for a certain period of time until the driver operates the vehicle.
• The auto brake is released if any of the following operations is performed.
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― Accelerator pedal is depressed
― Brake pedal is depressed
― Electric parking brake is operated
― Selector lever position is in R position
• The auto brake is released and the electric parking brake takes over if any of the following operations is performed.
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― Driver's seat belt is unfastened
― Driver's door is opened
― Ten min have elapsed since vehicle was stopped
Structural view
Function
• The smart brake support (SBS) [forward detection] has the following functions.
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― The front radar sensor and the forward sensing camera (FSC) detect a vehicle ahead, pedestrians, or bicycles, and if the body control module (BCM) determines that there is the possibility of a collision, an intermittent warning sound is activated continuously and, at the same time, the smart brake support (SBS) warning indications on the multi-information display and the active driving display flash.
― If the driver monitoring camera unit determines that the driver is not looking straight ahead, and determines that there is the possibility of a collision with an obstruction, it performs an early collision warning regardless of the warning timing set by the driver. (With driver monitoring camera)
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Note
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Reflects the determination results of the driver monitoring camera unit when the vehicle speed is 60 km/h {37 mph} or more and the vehicle is driven straight.
― When the front radar sensor and forward sensing camera (FSC) detect a vehicle ahead, pedestrians, or bicycles and the body control module (BCM) determines that the detecting vehicle is approaching it, it implements a brake prefill to eliminate the play between the brake pads and the disc rotor to obtain immediate brake force when the driver depresses the brake pedal.
― The front radar sensor and the forward sensing camera (FSC) detect a vehicle ahead, pedestrians, or bicycles, and if the body control module (BCM) determines that there is the possibility of a collision, it performs brake control (damage reduction braking).
System conditions display
• The smart brake support (SBS) [forward detection] system notifies the driver of the system status using the smart brake support (SBS) OFF indicator light, the active driving display, and the multi-information display.
smart brake support (SBS) [forward detection] display function table
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Status
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Display content
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Smart brake support (SBS) OFF indicator light
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i-ACTIVSENSE warning light
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Active driving display
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Multi-information display
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SBS [forward detection] OFF
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Switch the main power ON (READY on).
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SBS [forward detection] system is stopped
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ON
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OFF
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No display
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No display
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No display
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SBS [forward detection] ON
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SBS [forward detection] system is operating
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OFF
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OFF
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No display
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No display
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No display
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There is possibility of collision with vehicle ahead or obstruction ahead
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During collision warning/brake control (damage reduction braking) operation
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OFF
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OFF
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No display
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Approx. 2s have elapsed since vehicle was stopped by brake control (damage reduction braking) operation
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Driver depresses brake or gas pedal
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OFF
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OFF
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No display
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No display
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No display
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Driver does no depress accelerator or brake pedal
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OFF
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OFF
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No display
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No display
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Abnormality occurred in SBS [forward detection] system
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Malfunction occurred in SBS [forward detection] system
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ON
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ON
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No display
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No display
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SBS [forward detection] system stopped temporarily due to dirty front radar sensor
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ON
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ON
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No display
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Note
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• If an abnormality occurs in the smart brake support (SBS) [forward detection] system, a warning message is displayed on the center display. For the message content and verification method, refer to [CENTER DISPLAY] in the workshop manual.
System wiring diagram
Block diagram
Operation
• At the same time, the body control module (BCM) outputs a warning sound through the notification and warning speaker (front).
• The instrument cluster displays a warning indication on the multi-information display based on the warning request signal.
• The active driving display displays a warning based on the warning request signal.
• The DSC performs brake prefill control based on the brake prefill request signal.
• Then, if the driver does not perform an avoidance maneuver and there is the possibility of a collision, it sends a brake control (damage reduction braking) request signal to the electronically controlled brake unit from the body control module (BCM) to operate the brake control (damage reduction braking). At the same time, the body control module (BCM) outputs a warning sound signal through the notification and warning speaker (front) and the notification and warning speaker (front) activates the warning sound.
• The smart brake support (SBS) [forward detection] operates when all of the following conditions are met.
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― smart brake support (SBS) [forward detection] is not stopped
― For a vehicle ahead
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• Vehicle speed is approx.4km/h {2.5mph} or more
• Difference in vehicle speed between vehicle ahead and detecting vehicle approaching is 4 km/h or more
― For pedestrians or bicycles
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• Vehicle speed is within approx. 10km/h {6.2mph} to 80km/h {50mph}
― DSC control is not performed
― Smart brake support (SBS) [forward detection] has not been turned off using personalization features
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Note
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• The smart brake support (SBS) [forward detection] operates even if the DSC operation is inhibited by operating the DSC OFF switch and the DSC OFF indicator light is turned on. If the smart brake support (SBS) [forward detection] operates while the DSC has been inhibited, the DSC transitions to permit status and the DSC OFF indicator light turns off.
• The smart brake support (SBS) [forward detection] may not operate normally under the following conditions.
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― Vehicle ahead or obstruction ahead is significantly offset from center of detecting vehicle
― Driving at same speed as vehicle ahead
― Accelerator pedal is suddenly depressed
― Brake pedal is depressed
― Steering wheel is operated
― Selector lever is operated
― Turn signal indicator light is flashing
― Vehicle ahead is not equipped with taillights or vehicle ahead is traveling at night without turning on taillights
― Vehicle posture is largely changed by load condition
― When cornerin
― Driving on continuously curving road
― Suddenly cutting into lane or being cut off
― Road with repetitive up and down slopes
― Driving on poor roads or unpaved roads
― Warning or message due to soiling related to forward sensing camera (FSC) and front radar sensor is displayed on multi-information display
• The following vehicles or objects are recognized as a vehicle ahead or an obstruction, and the smart city brake support (SBS) may operate.
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― Objects close to entrance of curve
― On-coming vehicle appears while vehicle is cornering to left
― Narrow railing on bridge, narrow gate or entrance
― Near boundary of slope and flat road surface such as at entrance to underground parking area
― Speed restriction bumps, projections, and reflective metallic objects set up on road
― Vehicle or obstruction approaches detecting vehicle suddenly
― Tall plants and high-standing grass and forage
― Curtain or flag-shaped plastic objects
― Animals, walls, and standing trees
• When the body control module (BCM) determines that there is the possibility of a collision based on information detected by the front radar sensor, such as the distance and relative speed with the vehicle ahead, or information sent from the FSC, it changes the mode in the order of [Warning], [Gentle brake], and [Main brake] to prepare for the possible collision.
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Note
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• The mode does not always change in the order of [Warning], [Gentle brake], and [Main brake]. Main brake (brake control (damage reduction braking)) may be performed depending on the situation.
Collision warning/brake prefill operation
Solenoid valve operation table
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Traction control solenoid valve
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Stability control solenoid valve
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Inlet solenoid valve
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Outlet solenoid valve
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Pump motor, pump
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LF
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RF
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LR
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RR
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LF
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RF
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LR
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RR
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LF
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RF
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LR
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RR
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OFF (open)
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OFF (closed)
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OFF (open)
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OFF (closed)
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Operation
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Hydraulic circuit diagram
Block diagram
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• If the front radar sensor and the forward sensing camera (FSC) detect a vehicle ahead, pedestrians, or bicycles, target information (1) is sent to the body control module (BCM).
• At the same time, the body control module (BCM) outputs a warning sound signal to the notification and warning speaker (front), and the notification and warning speaker (front) activates the warning sound.
• When the instrument cluster receives the collision warning request signal (2), it displays (3) the smart brake support (SBS) warning indication on the multi-information display.
• When the active driving display receives the collision warning request signal (2), it displays the smart brake support (SBS) warning indication (3).
• When the electronically controlled brake unit receives (2) the brake prefill request signal, it operates (3) the pump motor, and by conducting (4) the brake fluid pressure generated by the pump motor to the caliper pistons, the clearance between the brake pads and disc plates is maintained in a narrowed condition.
• As a result, if the driver recognizes a vehicle ahead, pedestrian, or bicycle and depresses the brake pedal, or the driver does not perform an avoidance maneuver and the brake control (damage reduction braking) is operated, braking force is generated immediately and the braking distance is reduced.
Brake control (damage reduction braking) operation
Solenoid valve operation table
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Traction control solenoid valve
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Stability control solenoid valve
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Inlet solenoid valve
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Outlet solenoid valve
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Pump motor, pump
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LF
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RF
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LR
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RR
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LF
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RF
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LR
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RR
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LF
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RF
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LR
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RR
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ON (closed)
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ON (open)
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OFF (open)
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OFF (closed)
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Operation
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Hydraulic circuit diagram
Block diagram
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• If the driver does not perform an avoidance maneuver after the collision warning/brake prefill operation and the possibility of a collision increases further, the body control module (BCM) sends a gentle brake request signal/main brake request signal (1) to the electronically controlled brake unit.
• When the electronically controlled brake unit receives the gentle brake request signal/main brake request signal (1), it energizes the linear control solenoid valve, switches the hydraulic circuits, and increases the brake fluid pressure. As a result, the brake control (damage reduction braking) operates (2).
• While the brake control (damage reduction braking) is operating, a brake light signal (2) from the electronically controlled brake unit is sent to the electrical supply unit (ESU), and the electrical supply unit (ESU) turns on (3) the brake lights. The electrical supply unit (ESU) sends a brake light status signal (3) to the electronically controlled brake unit.
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Gentle brake (brake control (damage reduction braking))
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• The body control module (BCM) sends a gentle brake request signal to the electronically controlled brake unit based on the distance between vehicles information and the relative vehicle speed information from the front radar sensor and the forward sensing camera.
• When the electronically controlled brake unit receives the gentle brake request signal, it energizes the linear control solenoid valve, switches the hydraulic circuits and pressurizes the brake fluid, and then gentle braking is performed.
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Main brake (brake control (damage reduction braking))
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• From the gentle brake mode condition, if the vehicle further approaches the vehicle ahead, pedestrian or bicycle and the body control module (BCM) determines that avoiding a collision is difficult, it sends a main brake request signal to the DSC HU/CM and the mode is changed to main brake mode.
• The electronically controlled brake unit increases the pump motor output according to the deceleration speed requested by the main brake request signal, and increases the brake fluid pressure more than for the gentle brake to generate a greater brake force.
