Pre-Collision Safety System

SYSTEM OUTLINE

Pre-collision safety system is designed to reduce damage in a crash, working with the millimeter wave radar sensor and the distance control ECU by activating appropriate characteristics of the occupant crash protection and the crash condition easing system.

The millimeter wave radar sensor detects a vehicle and an obstacle on the roads and the distance control ECU judges in advance if a crash is inevitable, considering from the object's position, speed and course. The distance control ECU sends the information through CAN to the seat belt control ECU and skid control ECU with actuator, which activates the seat belt operation and the brake assist operation respectively. When the air suspension ECU receives the information of inevitable crash, damping force of shock absorber is adjusted and sinking of the vehicle front side (Brake dive) is prevented at full braking.

In pre-collision safety system failure, "Check PCS System" is shown on multi-display in the combination meter. When the system is not available due to dust and dirt on the radar, "PCS not Available Now" is shown on the display.

1. SEAT BELT OPERATION
When the millimeter wave radar sensor and the distance control ECU detect an object to be crashed in due course and judges that a crash is inevitable with it, the operation request signal is sent from the distance control ECU to rewind the seat belt by motor before the crash to reduce damage in the crash. When the driver brakes hard suddenly and it is judged as full braking, the operation request signal is sent from the skid control ECU with actuator to rewind the seat belt by motor.

2. BRAKE ASSIST OPERATION
Brake assist operation will activate by the driver's stepping on the brake pedal (Which is detected by hydraulic pressure sensor) when the millimeter wave radar sensor and the distance control ECU detect an object to be crashed in due course and judges that a crash is inevitable with it. The brake assist operation will activate immediately after the judgment of inevitable crash if brake has been applied before the judgment. However, please note that it effects only when the driver applies another brake.

3. ELECTRONICALLY MODULATED AIR SUSPENSION
Electronically modulated air suspension will activate when the millimeter wave radar sensor and the distance control ECU detect an object to be crashed in due course and judges that a crash is inevitable with it.