PRE-CRASH SAFETY SYSTEM SYSTEM DESCRIPTION

PRE-CRASH SAFETY SYSTEM DESCRIPTION

1. The pre-crash safety system detects vehicles and obstacles in front of the vehicle and performs the following: 1) the system uses the multi-information display and sounds a buzzer to warn the driver of a crash and prompt preventive action, and 2) uses system controls to reduce impact during a crash.

PRE-CRASH DETECTION OUTLINE

1. Front crash detection

   1. The driving support ECU receives information about vehicles and obstacles in front of the vehicle from the millimeter wave radar sensor assembly. Then, based on vehicle speed, road conditions and obstacle location, the driving support ECU determines, in advance, the possibility of a crash and if a crash is unavoidable.

2. Sudden braking detection

   1. The skid control ECU activates the pre-crash seat belts when it detects sudden braking. Sudden braking is determined based on brake oil pressure and other information from the master cylinder pressure sensor.

3. Vehicle control impossible judgment

   1. The pre-crash seat belts are activated when it is determined that there is a high probability that the vehicle cannot be controlled. The judgment is based on vehicle stability information from the yaw rate sensor and steering angle sensor.

4. Component

   Component	Detection Content
   Millimeter wave radar sensor assembly	Front object

PRE-CRASH SAFETY SYSTEM CONTROL DESCRIPTION

PRE-CRASH ALARM CONTROL

1. When the system determines that there is a possibility of a crash with an obstacle in front of the vehicle, the multi-information display and warning buzzer are used to warn the driver and help with crash avoidance.

PRE-CRASH SEAT BELT CONTROL

1. When the system determines that a crash with an obstacle is unavoidable, that sudden braking has occurred, or that vehicle control is impossible, the system performs seat belt control. During seat belt control, slack in the seat belts is reduced to aid the pretensioner.

PRE-CRASH BRAKE ASSIST CONTROL

1. When the system determines that there is a possibility of a crash with an obstacle in front of the vehicle, brake assist is set to standby mode. Then, when the driver depresses the brake pedal, the hydraulic brake pressure is increased to improve braking effectiveness.

AIR SUSPENSION CONTROL

1. When it is determined that there is a possibility of colliding with an obstacle in front of the vehicle, the AVS is operated to control the damping force, suppress nose diving and rolling, and support crash avoidance through steering.

PRE-CRASH BRAKING CONTROL

1. When the system determines that a crash with an obstacle is unavoidable, the system performs brake control to reduce the vehicle speed.

PRE-CRASH BRAKE CANCEL SWITCH ASSEMBLY

1. When the pre-crash brake cancel switch assembly in the No. 1 instrument panel under cover sub-assembly is turned on, the pre-crash alarm and pre-crash brake do not operate.

   Tip:

   While the pre-crash brake cancel switch assembly is on, the PCS indicator light in the combination meter assembly illuminates.

PRE-CRASH SAFETY SYSTEM OPERATING CONDITION

PRECAUTION FOR MILLIMETER WAVE RADAR SENSOR ASSEMBLY

1. When the millimeter wave radar sensor assembly detects an object in front of the vehicle under the conditions described below, the driving support ECU may determine that a crash is unavoidable and activate the pre-crash safety system. However, this is not abnormal.

   

   Tip:

   • The pre-crash safety system is not activated by safety cones and other plastic objects which cannot be detected by the millimeter wave radar sensor assembly.

   • The pre-crash safety system may or may not be activated by the following objects which cannot always be detected by the millimeter wave radar sensor assembly: people, bicycles, motorcycles, trees, animals, snow fences, etc.

   Object Type	Example
   Object that cannot be detected	Safety cones, plastic items
   Object that cannot always be detected	People, bicycles, motorcycles, trees, animals, snow fences, etc.