PRE-CRASH SAFETY SYSTEM CONTROL PRE-CRASH SAFETY CONTROL

  1. FUNCTION OF MAIN COMPONENTS

    Item

    Function

    Combination Meter Assembly

    PCS OFF Warning Light

    • 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.

    PCS Warning Light

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

    Buzzer

    Sounds to warn the driver in accordance with signals from the pre-crash safety city sensor when the system is malfunctioning.

    Pre-crash Safety City Sensor

    Determines whether the possibility of a collision is high or a collision is unavoidable based on the information received from the pre-crash safety city sensor. It then outputs a brake assist standby request signal and pre-crash brake request signal if required.

    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.

    Speed Sensors

    Detect the wheel speed of each of the 4 wheels and transmits the signals to the skid control ECU.

    Airbag Sensor Assembly

    Yawrate Sensor

    Detects the yaw rate and lateral/longitudinal deceleration of the vehicle and transmits the signal to the pre-crash safety city sensor.

    Spiral Cable Sub-assembly

    Steering Sensor

    Detects the angle and direction of steering and transmits a signal to the pre-crash safety city sensor.

    Pre-crash System Cancel Switch Assembly

    • Switches between the 3 warning timings (Far, Middle and Near) when pressed.

    • Disables the pre-crash safety system when pressed and held.

    Stop Light Switch Assembly

    Detects if the brake pedal is depressed and transmits a signal to the pre-crash safety city sensor.

    VSC OFF Switch

    Disables the pre-crash brake and pre-crash brake assist operation when the switch is turned on.

  2. 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).

        Y180840E01

      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).

        Y180841E01

    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 PCS warning light in the combination meter assembly blinks 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 (braking).

        Y180842E03

    3. Operating Conditions

      1. The pre-crash safety system operates when the driving support ECU assembly determines there is a high possibility of a collision, or an unavoidable collision with an obstacle in front of the vehicle.

        Operating Conditions

        Pre-crash safety system operation has not been disabled using pre-crash system cancel switch assembly

      2. The following pre-crash safety system controls are performed under the following conditions.

        Control

        Condition

        Pre-crash Warning

        • Vehicle speed is approximately 15 km/h (10 mph) to 140 km/h (87 mph).

        • The relative speed of obstacle or vehicle ahead is approximately 15 km/h (10 mph) or higher.

        • Pre-crash safety system operation has not been disabled using pre-crash system switch assembly.

        Pre-crash Brake

        • Vehicle speed is approximately 10 km/h (6 mph) to 80 km/h (50 mph).

        • The relative speed of obstacle or vehicle ahead is approximately 10 km/h (6 mph) or higher.

        • Pre-crash safety system operation has not been disabled using pre-crash system switch assembly.

        • VSC system has not been disabled.

        Pre-crash Brake Assist

        • Vehicle speed is approximately 30 km/h (19 mph) to 80 km/h (50 mph).

        • The relative speed of obstacle or vehicle ahead is approximately 30 km/h (19 mph) or higher.

        • Brake pedal is depressed.

        • Pre-crash safety system operation has not been disabled using pre-crash system switch assembly.

        • VSC system has not been disabled.

  3. DIAGNOSIS

    1. Initial Check

      1. The pre-crash safety city sensor performs an initial check on the system for approximately 3 seconds after the engine switch has been turned on (IG).

    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.