PRE-CRASH SAFETY SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Pre-crash Safety City Sensor

    • Acquires information about a preceding vehicle from a monocular camera sensor and laser sensor to perform pre-crash safety system control.

    • Sends the information display, PCS OFF warning light and multi buzzer signals to the combination meter assembly based on pre-crash control information.

    • Transmits an operation signal to the camera heater.*
    Camera Heater (Pre-crash Safety City Heater)* The camera heater is heated according to signals from the pre-crash safety city sensor.
    PCS Switch

    • Turn the pre-crash safety system on/off.

    • Switches between the 3 warning timings (Far, Middle and Near) when pressed.
    VSC OFF Switch Switches the brake system to TRC OFF mode or VSC OFF mode when operated by the user, and also turns off the pre-crash brake assist and pre-crash brake functions (the warning function can still operate).
    Yawrate Sensor Detects the yaw rate and longitudinal and lateral acceleration speeds of the vehicle, and sends signals to the pre-crash safety city sensor via CAN communication.
    Speed Sensors Detects the wheel speed and sends signals to the skid control ECU.
    Stop Light Switch Assembly Detects when the brake pedal is depressed and sends signals to the pre-crash safety city sensor and skid control ECU.
    Steering Sensor Detects the steering angle and direction and sends signals to the pre-crash safety city sensor via CAN communication.
    ECM

    • Detects the shift position signal and accelerator pedal opening angle and sends that information to the pre-crash safety city sensor.

    • Performs engine output control based on information from the pre-crash safety city sensor.
    Main Body ECU (Instrument Panel Junction Block Assembly) Outputs vehicle specification information.

    Brake Actuator Assembly


    • Skid Control ECU

    • Receives a brake assist standby request signal from the pre-crash safety city sensor and switches the brake assist to standby mode. When a stop light switch signal is input, it activates the brake assist.

    • Receives a pre-crash brake request signal from the pre-crash safety city sensor, and then applies the brakes.

    • Transmits vehicle speed signals to the pre-crash safety city sensor.
    Combination Meter Assembly

    • Illuminates to warn the driver in accordance with signals from the pre-crash safety city sensor.

    • Flashes when the system is malfunctioning or temporarily disabled.

    • Illuminates when the pre-crash safety system is not available due to certain reasons or when pre-crash brake and pre-crash brake assist operation are disabled since the VSC system has been disabled.

    • Displays a warning message to inform or warn the driver of the system condition in accordance with signals from the pre-crash safety city sensor.

    • Sounds the multi buzzer according to signals from the pre-crash safety city sensor.

    • *: Models with camera heater

  2. FUNCTION


    1. The pre-crash safety system uses the monocular camera sensor and laser sensor inside the pre-crash safety city sensor to determine if there is a risk of this vehicle colliding with the preceding vehicle.

    2. When the probability of a collision is high, the pre-crash safety system sends a warning via the meter display and buzzer, and performs brake assist control. Additionally, when the probability of a collision is extremely high, the system performs brake control in order to reduce the impact force if a collision occurs.

    3. During brake control by the pre-crash safety system, the skid control ECU illuminates the stop light in order to inform any following vehicles that this vehicle is braking.

      A004MIWE02
      Text in Illustration
      *a This Vehicle *b Probability of collision extremely high
      *c Preceding Vehicle *d The illustrations shown are examples only.
      A004LWS Laser Sensor Detection Area A004LYO Monocular Camera Sensor Image Recognition Area

  3. OPERATING CONDITION


    1. The pre-crash safety system is enabled and determines that the possibility of a frontal collision with a vehicle is high.

      Pre-crash Safety System Operating Conditions
      Pre-crash Warning

      • Vehicle speed is approximately 15 to 140 km/h (10 to 86 mph).

      • The relative speed between your vehicle and the vehicle ahead is greater than approximately 15 km/h (10 mph).
      Pre-crash Brake Assist

      • Vehicle speed is approximately 30 to 80 km/h (19 to 49 mph).

      • The relative speed between your vehicle and the vehicle ahead is greater than approximately 30 km/h (19 mph).

      • The brake pedal is being depressed.
      Pre-crash Braking

      • Vehicle speed is approximately 10 to 80 km/h (7 to 49 mph).

      • The relative speed between your vehicle and the vehicle ahead is greater than approximately 10 km/h (7 mph).

      Tech Tips

      In case of the following, the system will not operate:


      • Steering Sensor zero point calibration has not been completed

      • If VSC is disabled (only the pre-crash warning function will be operational)

      • If the PCS OFF warning light is flashing or illuminated

      • If the shift position is in R

    2. If either of the following situations occur while the pre-crash brake function is operating, it will be canceled:


      • The accelerator pedal is depressed strongly

      • The steering wheel is turned sharply or abruptly

    3. If the vehicle is stopped by the operation of the pre-crash brake function, the operation of the pre-crash brake function will be canceled after the vehicle has been stopped for approximately 2 seconds.

    4. When the driver is depressing the brake pedal, the system judges that the driver is preparing to avoid a collision, so the system may delay the pre-crash brake activation timing.

    5. During the following, the driver operations takes precedence and the system may not operate:


      • The accelerator pedal is depressed strongly

      • The steering wheel is turned sharply or abruptly

    6. In some situations such as the following, the system may determine that there is a possibility of a frontal collision and operate:


      • When passing a vehicle in an oncoming lane that is stopped to make a left/right turn

        A004M29

      • When passing an oncoming vehicle while making a left/right turn

        A004MB9

      • When driving on a road where relative location to vehicle ahead in an adjacent lane may change, such as on a winding road

        A004MBQ

      • When rapidly closing on a preceding vehicle

        A004LXO

      • If the front of the vehicle is raised or lowered, such as when the road surface is uneven or undulating

      • When passing extremely close to a vehicle or structural object

        A004ME2

      • When there is a vehicle or object by the roadside at the entrance of a curve

        A004LZZ

      • When driving on a narrow path surrounded by a structure, such as in a tunnel or on an iron bridge

      • When there is a reflective object (manhole cover, steel plate, etc.), steps, dip, or a protrusion on the road surface or roadside

        A004LUM

      • When passing through a place with a low structure above the road (low ceiling, traffic sign, etc.)

        A004LSY

      • When there is a structural object (overpass, traffic sign, billboard, street light, etc.) at the top of an uphill road

        A004M0Z

      • When rapidly closing on an electric toll gate barrier, parking area barrier, or other barrier that opens and closes

        A004M56

      • When using an automatic car wash

      • When approaching a low hanging object that may contact the vehicle, such as a banner, tree branches or thick grass

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      • When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead

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      • When driving through steam or smoke

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      • When there are patterns or paint on the road or a wall that may be mistaken for a vehicle

      • When the front part of the vehicle is raised or lowered

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      • When the pre-crash safety city sensor is misaligned due to a strong impact being applied to the pre-crash safety city sensor, etc.

        A004LX5

      • When the vehicle is being parked in a place where there is a low hanging object at the height of the pre-crash safety city sensor

        A004LXB

      • When the windshield glass is covered with raindrops, etc.

        A004MAI

    7. In some situations such as the following, a vehicle may not be detected by the pre-crash safety city sensor, preventing the system from operating properly:


      • If an oncoming vehicle is approaching your vehicle

      • When approaching the side or front of a vehicle

      • If a preceding vehicle has a small rear end, such as an unloaded truck

      • If a preceding vehicle has a low rear end, such as a low bed trailer

        A004M57

      • If a vehicle ahead is carrying a load which protrudes past its rear bumper

      • If a vehicle ahead has extremely high ground clearance

        A004LYB

      • If a vehicle ahead is irregularly shaped, such as a tractor or side car

      • If the sun or other light is shining directly on a vehicle ahead

      • If a vehicle cuts in front of your vehicle or emerges from beside a vehicle

        A004M0G

      • If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, acceleration or deceleration)

      • When suddenly cutting behind a preceding vehicle

      • When a vehicle ahead is not directly in front of your vehicle

        A004LOF

      • When driving in inclement weather such as heavy rain, fog, snow or a sand storm

        A004LT0

      • When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead

      • When driving through steam or smoke that may obscure vehicles ahead

      • When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel

      • When a very bright light, such as the sun or the headlights of oncoming traffic, shines directly into the pre-crash safety city sensor

        A004M47

      • When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel

        A004MBW

      • While driving on a curve and for a certain amount of time after driving on a curve

      • If your vehicle is skidding

        A004MC0

      • When the front part of the vehicle is raised or lowered

        A004LZ2

      • If the wheels are misaligned

      • If a wiper blade is blocking the pre-crash safety city sensor

      • The vehicle is wobbling

      • The vehicle is being driven at extremely high speeds

      • When driving on roads with sharp bends or uneven surfaces

      • When a preceding vehicle is a poor reflector of laser

      • When the pre-crash safety city sensor is misaligned due to a strong impact being applied to the pre-crash safety city sensor, etc.

        A004LX5

    8. In some situations such as the following, sufficient braking force may not be obtained, preventing the system from performing properly:


      • If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet

      • If the vehicle is not properly maintained (brakes or tires are excessively worn, improper tire inflation pressure, etc.)

      • When the vehicle is being driven on a gravel road or other slippery surface

    9. If the PCS OFF warning light Illuminates or flashes and a warning message is displayed on the multi-information display, the pre-crash safety system may be temporarily unavailable or there may be a malfunction in the system.


      1. In the following situations, the warning light will turn off, the message will disappear and the system will become operational when normal operating conditions return:


        • When the area around the pre-crash safety city sensor is hot, such as in the sun

        • When the windshield glass is fogged up, or covered with condensation or ice

        • When the pre-crash safety city sensor or the area around the sensor is cold, such as in an extremely cold environment

        • If the area in front of the pre-crash safety city sensor is obstructed, such as when the hood is open

      2. If the PCS OFF warning light continues to flash or the warning message does not disappear, the system may be malfunctioning.

    10. If VSC is disabled, the pre-crash brake assist and pre-crash brake functions are also disabled. However, the pre-crash warning function will still operate.

  4. SYSTEM CONTROL


    1. Pre-crash Brake Assist


      1. When the driver depresses the brake pedal after the pre-crash safety city sensor has determined that there is the possibility of a collision, brake fluid pressure is increased. If the possibility of a collision is still high, brake fluid pressure is further increased (pre-crash brake assist operation without initial braking).

        A004LVBE19

      2. If the driver is depressing the brake pedal when the pre-crash safety city sensor determines that the possibility of a collision is high, brake fluid pressure is increased immediately (pre-crash brake assist operation with initial braking).

        A004LP7E01

    2. Pre-crash Brake


      1. When the pre-crash safety city sensor detects an object in front of the vehicle and determines that the possibility of a collision is high, the combination meter in the warning message and a warning buzzer sounds to warn the driver.

      2. When the pre-crash safety city sensor determines that a collision is unavoidable, the system performs pre-crash brake control.

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  5. CONSTRUCTION


    1. Pre-crash Safety City Sensor


      1. The pre-crash safety city sensor consists of a laser sensor, monocular camera sensor and CSP ECU. 2 types of sensors such as the laser sensor and camera sensor are used to ensure accurate and reliable detection.

        A004M2QE02
        Text in Illustration
        *1 Pre-crash Safety City Sensor - -
        *a Monocular camera sensor *b Laser sensor
        *c Laser sensor recognition range *d Monocular camera sensor recognition range

      2. Monocular Camera Sensor


        • The camera sensor detects three-dimensional objects on or near the road ahead while driving and determines whether it is necessary to avoid a collision with the object.

      3. Laser Sensors


        • The laser sensors detect vehicles or other objects on or near the road ahead while driving and determine whether a collision is imminent based on the location, speed and heading of the vehicle or object.

    2. Camera Heater (Pre-crash Safety City Heater) (Models with Camera Heater)


      1. The pre-crash safety city heater, which is installed between the pre-crash safety city sensor and windshield glass, is heated the heater pattern area according to signals from the pre-crash safety city sensor in order to prevent the windshield glass on the front of the pre-crash safety city sensor from fogging, and also to remove fog buildup.

        A004LQUE02
        Text in Illustration
        *a Camera Heater (Pre-crash Safety City Heater) *b Heater Pattern
        *c The illustration is an external view. The illustration is a representative example for the structure explanation. - -

      2. When all of the following conditions have been met, the camera heater operates.


        • System malfunction is not detected.

        • Ignition switch is turned to ON.

        • Ambient temperature 5 °C (41 °F) or less.

        • When the ambient temperature is between 5°C (41°F) and 20°C (68°F) and the windshield glass on the front of the pre-crash safety city sensor begins to fog up while driving (fogging detected in the pre-crash safety city sensor).

      3. After the camera heater is activated, the camera heater briefly stops operating every 30 minutes. When the above conditions are met after the camera heater stops operating, the camera heater activates again.

    3. Combination Meter Assembly


      1. The combination meter assembly uses the multi-information display, PCS OFF warning light and multi buzzer to provide the driver with pre-crash safety system warnings and indications.

      2. If the pre-crash safety city sensor determines that the possibility of a collision is high, it sends a signal to the combination meter assembly. Upon receiving this signal, the combination meter assembly indicates a warning using the multi-information display and sounds multi buzzer. Details are indicated below.

        When there is a high possibility of a collision
        Multi-information Display Master Warning Light PCS OFF Warning Light Multi Buzzer
        BRAKE! - - Sounds Intermittent

      3. When the system is not available, the following warning occurs to warn the driver.

        When a system malfunction is detected
        Multi-information Display Detail PCS OFF Warning Light Master Warning Light Multi Buzzer
        Check Pre-Crash Safety. This message appears when the pre-crash safety city sensor detects a system malfunction. Flashes Illuminates Sounds once
        Pre-Crash Safety temporarily not available*

        This message appears when the pre-crash safety city sensor determines either of the following conditions is present:


        • Poor weather conditions

        After these conditions have been resolved, the system will operate normally.

        		 Illuminates - -
        Front sensor system are temporarily unavailable due to inappropriate temp. Wait a moment.*

        This message appears when the pre-crash safety city sensor determines either of the following conditions is present:


        • Temperature of pre-crash safety city sensor is abnormal

        		 Illuminates - -
        Front Camera Vision Blocked Clean and Demist Windshield*

        This message appears when the pre-crash safety city sensor determines either of the following conditions is present:


        • Dirty windshield glass

        • windshield glass fogging

        		 Illuminates - -

        Tech Tips

        *: The message appears for 6 seconds on the multi-information display.

        When the VSC OFF switch is pressed
        Multi-information Display Detail PCS OFF Warning Light Multi Buzzer
        Pre-Crash Brake is disabled due to VSC OFF.* Pre-crash brake and pre-crash brake assist operation is disabled (the warning for when there is a high possibility of a collision is still enabled). Illuminates -

        Tech Tips

        *: The message appears for 6 seconds on the multi-information display.

    4. PCS Switch


      1. A PCS switch is provided to disable the system. When pressed and held for approximately 3 seconds, the pre-crash safety system will be disabled. A message will be displayed for 6 seconds and the pre-crash warning light will be illuminated. When the switch is pressed again while the system is disabled, the system will be reenabled.

      2. The switch is also used to change the warning timing in 3 levels: far, middle, near. The warning timing changes in the order below each time the switch is pressed.

        A004LNZE04
        A004LMN PCS switch is pressed briefly A004LTW PCS switch is pressed and held for 3 seconds
        A004LZ7 Returns to previous screen when the switch is not operated for 6 seconds - -

  6. DIAGNOSIS


    1. Initial Check


      1. The pre-crash safety city sensor performs an initial check on the system for approximately 3 seconds after the ignition switch has been turned to ON.

    2. Monitor Function


      1. After completing the initial check, the pre-crash safety system becomes ready to operate. During this time, the pre-crash safety city sensor periodically monitors the system for any malfunctions.

    3. Diagnostic Trouble Code (DTC)


      1. If the pre-crash safety city sensor detects a malfunction in the pre-crash safety system, it stores a 5 digit Diagnostic Trouble Code (DTC) in memory.