ROAD SIGN ASSIST SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Components Function
    Pre-crash Safety City Sensor Monocular Camera Captures road signs.
    Pre-crash Safety City Sensor ECU Performs RSA system control based on information of road signs captured by the monocular camera.
    Pre-crash Safety City Heater Heats the heater pattern area in accordance with the signals from the pre-crash safety city sensor.
    Spiral Cable with Sensor Sub-assembly Steering Sensor Detects the steering direction and angle of the steering wheel.
    Airbag Sensor Assembly Yawrate Sensor Sends yaw rate signals and the rate of deceleration and acceleration to the pre-crash safety city sensor.
    Speed Sensor Detects the wheel speed and transmits signals to the skid control ECU.
    Headlight Dimmer Switch Assembly Transmits a turn signal command to the combination meter assembly.
    Steering Pad Switch Assembly Sends a multi-information display operating signal to the combination meter assembly.
    Combination Meter Assembly Master Warning Light Illuminates when a system malfunction occurs.
    Multi-information Display

    • Displays road signs recognized by the pre-crash safety city sensor.

    • The RSA system can be turned on and off through the settings tab.
    Buzzer Sounds for speed limit exceeded, no overtaking and no entry notifications.
    ECM Sends a shift position signal to the pre-crash safety city sensor.
    Brake Actuator Assembly Skid Control ECU Sends a vehicle speed signal from the speed sensor to the pre-crash safety city sensor.
    Main Body ECU (Multiplex Network Body ECU) Sends country specification information signals to the pre-crash safety city sensor.
    Air Conditioning Amplifier Assembly Sends the outside temperature signal to the pre-crash safety city sensor.

  2. FUNCTION


    1. The RSA system recognizes the following traffic signals using the pre-crash safety city sensor.

      Category Sign Type Example of Recognizable Traffic Sign
      Speed Limit Round Maximum Speed Limit/End of Speed Limit A0044RP
      No Overtaking No Overtaking/End of No Overtaking A0044ZQ
      Supplemental Signs Road Condition Signs Ramp Way A0044XP
      Rain A0044OK
      Ice A0044S9
      End of Prohibition A004523

    2. The RSA system recognizes the following traffic signals using the pre-crash safety city sensor.

      Category Display Example Details
      Speed Limit Related A00457A

      • Informs the driver of the maximum speed limit of the currently driven road.

      • The displayed sign reflects the speed limit on the recognized sign.
      No Overtaking Related A0044KT Informs the driver when they are in a no overtaking zone on the currently driven road.
      All Canceled (All restrictions canceled. Return to default road regulations.) A004523 Informs the driver when all applicable prohibitions, such as speed limit and no overtaking, have ended.
      Speed Limit with Supplemental Sign Related Ramp Way A0044N4 Informs the driver of the ramp way direction. However, this item is not displayed when making a lane change without operating the turn signal light.
      Rain A0044Q2 Informs the driver of the maximum speed limit on the currently driven road when it is raining or the road surface is wet.
      Ice A0044LS Informs the driver of the maximum speed limit on the currently driven road when there is accumulated snow or ice.
      Blank A0045AW The display is blank when the system is unable to recognize a supplemental sign.

    3. Notification functions are used in the RSA system which inverts the colors of displayed signs, flash signs, etc. to notify the driver.


      1. Speed Limit Exceeded Notification


        • While a speed limit sign is displayed, if the actual vehicle speed exceeds the speed limit plus a designated threshold*, the colors of the displayed sign are inverted. For example, if the threshold is set to 5 km/h and the speed limit sign is 60 km/h, the colors of the displayed sign are inverted when the actual vehicle speed exceeds 65 km/h. Furthermore, the system also inverts a speed limit sign with supplemental sign in the same way. However, the system does not invert the colors of the supplemental sign.

        • The buzzer may be set to sound during notifications through the customization function. However, if a speed limit recognized from a speed limit with supplemental sign is exceeded, the buzzer does not sound.

        • This notification is judged according to the speed units estimated by the pre-crash safety city sensor. When moving to a region with different speed units, notifications may be incorrectly issued until learning is complete.

          Tech Tips

          *: The threshold can be adjusted to 1 of 3 levels through the customization function.

        Notification Method Display Example
        Inverted Display A00457T

      2. No Overtaking Notification


        • While a no overtaking sign is displayed, if the system detects that the vehicle is attempting to overtake another vehicle, the system flashes the displayed sign.

        • The buzzer may be set to sound during notifications through the customization function.

        Notification Method Display Example
        Flashing Display A0044VR

    4. The RSA can be turned on or off through the settings tab of the multi-information display.


      1. A customization function is used for the RSA, which allows settings such as the notification method and level for exceeding the speed limit to be changed. Setting changes are made through the customization tab of the multi-information display.

        A0044W5C01
        *a Vehicle Settings Tab *b The illustration shown is an example only.

  3. SYSTEM CONTROL


    1. RSA Control Pattern 1


      1. After a road sign is recognized by the pre-crash safety city sensor and the vehicle passes by, the sign is displayed on the multi-information display.

      2. While a sign is displayed on the multi-information display, if a new road sign is not recognized within a specified distance, display of the current sign is turned off.

        A00452RE04
        *1 Road Sign Recognized
        *2 Specified Distance Driven
        *3 Sign Display Off
        *4 Sign Display On

    2. RSA Control Pattern 2


      1. When the ignition switch is turned off while a sign is displayed on the multi-information display, the same sign is displayed when the ignition switch is turned ON again.

        A0044M3E09
        *1 Ignition switch is turned off.
        *2 Ignition switch is turned ON.
        *3 Sign Display On

    3. RSA Control Pattern 3


      1. While a sign is displayed on the multi-information display, the sign is turned off when turning left or right onto a new road.

        A00456QE02
        *1 Road Sign Recognized
        *2 Sign Display Off
        *3 Sign Display On

  4. CONSTRUCTION


    1. Pre-crash Safety City Sensor


      1. The RSA is controlled by the pre-crash safety city sensor.

      2. The pre-crash safety city sensor judges road signs recognized by the monocular camera and displays information based on these judgments on the multi-information display.

        A00450CE06

      3. When one of the following operations is conducted, the pre-crash safety city sensor angle must be adjusted. For details, refer to the Repair Manual.


        • The pre-crash safety city sensor is removed and reinstalled or replaced.

        • Parts relating to the tire or suspension are replaced or adjusted.

        • Strong force is applied onto the pre-crash safety city sensor.

    2. Pre-crash Safety City Heater


      1. The pre-crash safety city heater is installed to the pre-crash safety city sensor, which receives signals from each ECU and controls the pre-crash safety city heater so that it heats up to defog the area of the windshield glass in front of the pre-crash safety city sensor. For details about the pre-crash safety city heater, refer to the pre-crash safety system.

  5. OPERATION


    1. Combination Meter Assembly


      1. The combination meter assembly displays recognized signs on the multi-information display based on information of road signs recognized by the pre-crash safety city sensor.

      2. The RSA system display mode can be selected by switching the display mode of the multi-information display through operation of the steering pad switch assembly.

      3. When the driving assist system information tab is selected for display on the multi-information display, road signs recognized by the pre-crash safety city sensor are displayed on the upper portion of the multi-information display.

      4. A maximum of 3 signs can be displayed simultaneously. When 3 signs are displayed, the signs are displayed in the following order from left to right: speed limit related, speed limit with supplemental sign related and no overtaking related.

        A0044KOC01
        *a Driving Assist System Information Tab *b Speed Limit Related
        *c Speed Limit with Supplemental Sign Related *d No Overtaking Related
        *e The illustration shown is an example only. The illustration may differ from the actual vehicle screen. - -

      5. When an information tab other than the driving assist system information tab is selected for display on the multi-information display, road signs recognized by the pre-crash safety city sensor are displayed as pop-ups on the upper center portion of the multi-information display. Furthermore, the pop-up display is only for speed limit signs. It is not displayed for no overtaking signs and speed limit with supplemental signs.

        A004588C01
        *a Speed Limit Related *b Multiple Road Signs Recognized
        *c The illustration shown is an example only. The illustration may differ from the actual vehicle screen. - -

      6. When there is a malfunction in the RSA system or the system is temporarily unusable, a warning message is displayed on the multi-information display, the master warning light illuminates and the multi buzzer sounds.

        Condition Multi-information Display Indication Master Warning Light Buzzer
        System malfunction Check RSA System. Illuminates Sounds
        Pre-crash safety city sensor temperature outside of operational range. Front Camera Unavailable - -
        When there is poor visibility for the pre-crash safety city sensor. Front Camera Vision Blocked. Clean and Demist Windshield. - -

  6. DIAGNOSIS


    1. If a malfunction is detected in the RSA the pre-crash safety city sensor cancels the RSA, sounds the buzzer in the combination meter assembly, and displays a message on the multi-information display to inform the driver of the malfunction.

    2. At the same time, the malfunction is stored in memory as a Diagnostic Trouble Code (DTC). When a Global TechStream (GTS) is connected to the DLC3, the DTC can be read. For details, refer to the Repair Manual.