System Description
WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
- PRE-COLLISION SYSTEM
- The pre-collision system optimizes and activates occupant protection equipment (see below) to attempt to reduce damage due to a collision.
- OUTLINE OF PRE-COLLISION SYSTEM OUTLINE OF PRE-COLLISION SYSTEM
Operating Condition Control Transmitting ECU Receiving ECU Part operated Operates according to sensor detection Pre-collision seat belts Distance control ECU Seat belt control ECU Front seat outer belts Operates according to sensor detection Pre-collision brake assist Distance control ECU Skid control ECU Brake assist system Operates when sudden braking occurs Pre-collision seat belts Skid control ECU Seat belt control ECU Front seat outer belts - When operating according to sensor detection:
The millimeter wave radar sensor detects vehicles and other objects on the road in front of the user's vehicle. The distance control ECU determines if a collision is unavoidable based on object position, speed and track information. If the distance control ECU determines that a collision is unavoidable, it transmits this information to the following areas using CAN communication:
- Seat belt control ECU (initiates control of pre-collision seat belts)
- Skid control ECU (activates pre-collision brake assist system)
- When operating as a result of sudden braking:
The skid control ECU uses brake pressure information and other data to determine if the driver has suddenly applied the brakes. If so, the skid control ECU sends a signal to the seat belt control ECU through CAN communication and the pre-collision seat belt activates.
- When operating according to sensor detection:
- OUTLINE OF PRE-COLLISION SEAT BELT CONTROL
- The pre-collision seat belt operates depending on what the sensor detects, or whether sudden braking has occurred. The pre-collision seat belt motor tightens the seat belt to optimize occupant restraint performance.
- Operative condition
- Refer to the sensor and sudden braking descriptions under OUTLINE OF PRE-COLLISION SYSTEM .
- OUTLINE OF PRE-COLLISION BRAKE ASSIST SYSTEM
- The pre-collision brake assist system operates depending on what the sensor detects. The system then enters standby mode before a collision. When the driver depresses the brake pedal, brake fluid pressure is increased to improve fluid pressure response and improve vehicle speed reduction rate.
- Operative condition
- Refer to the sensor description under OUTLINE OF PRE-COLLISION SYSTEM .
- When the driver depresses the brake pedal after the distance control ECU determines that a collision is unavoidable: Brake fluid pressure is increased at the same time the driver depresses the brake pedal.
- When the driver depresses the brake pedal before the distance control ECU determines that a collision is unavoidable: Brake fluid pressure is increased at the same time that the distance control ECU receives a pre-collision sensor signal (indicating that other vehicles or objects are in front of the vehicle).
- OPERATIVE CONDITION AND INOPERATIVE CONDITION OF EACH CONTROL (REVIEW) OPERATIVE CONDITION AND INOPERATIVE CONDITION OF EACH CONTROL (REVIEW)
Pre-collision seat belts ((1)) Pre-collision seat belts ((2)) Pre-collision brake assist ((2)) Engine switch off or on (ACC) - - - When a warning message is displayed on the multi-information display (3) (3) (3) When seat belt(s) is / are fastened (4) (4) O Operates when the vehicle speed is 30 km/h or more, regardless of relative speed O - - Operates when the vehicle speed is 5 km/h or more and relative speed is 30 km/h - O O When the vehicle collides with an object outside the detection range of the millimeter wave radar sensor (side collision, rear collision, etc.) O - - When the millimeter wave radar sensor cannot detect a possible collision object O - - (1) Operator when brakes are suddenly applied. (2) Operator according to sensor detection. (3) Inoperative parts are different depending on malfunction areas. (4) Only operates when seat belt is fastened. - PRECAUTION FOR PRE-COLLISION SYSTEM OPERATION
- When the millimeter wave radar sensor detects an object in front of the vehicle under the conditions described below, the distance control ECU may determine that a collision is unavoidable, and activate the pre-collision system. This activation of the system is not abnormal.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
- The pre-collision system will not activate when the pre-collision sensor detects safety cones and other plastic objects.
- The pre-collision system may or may not activate when the pre-collision sensor detects the following objects: people, bicycles, motorcycles, trees, animals and snow fences.
OBJECT TYPE AND EXAMPLEObject Type Example Objects that cannot be detected Plastic items (safety cones) Objects that cannot be detected in a stable manner People, bicycles, motorcycles, trees, animals, snow fence, etc.