CRUISE CONTROL SYSTEM SYSTEM DESCRIPTION


  1. GENERAL

    This system is controlled by the ECM, and control is performed using the throttle body with motor assembly and motor drive force. The ECM controls the following functions: cruise control main, - (COAST)/SET, + (ACCEL)/RES (RESUME), CANCEL and vehicle speed operation.


    • The ECM compares the vehicle speed from the speed sensors with the stored vehicle speed set using the steering pad switch assembly. The ECM increases the opening angle of the throttle valve when the actual vehicle speed is below the stored vehicle speed, and decreases the opening angle of the throttle body when the actual vehicle speed is more than the stored vehicle speed.

    • The ECM assembly receives signals from the steering pad switch assembly indicating when the cruise control main switch, - (COAST)/SET switch, + (ACCEL)/RES (RESUME) switch, CANCEL switch, etc., is pushed.

    • The ECM illuminates the combination meter assembly cruise control indicator when the cruise control system is turned on using the cruise control main switch.

    • The ECM turns off the combination meter assembly cruise control indicator and displays a warning message when a malfunction occurs during cruise control driving.

    • B000U39C52
      *a Cruise Control Indicator
      *b Cruise Control SET Indicator

      The ECM illuminates the combination meter assembly cruise control SET indicator when vehicle speed control begins after the cruise control main switch is pushed to -SET while driving.

  2. FUNCTION OF MAIN COMPONENTS


    1. The main components of the cruise control system have the following functions:

      Component Function
      Steering Pad Switch Assembly Cruise Control Main Switch Turns the cruise control system on and off.
      CANCEL Switch Outputs a cancel signal to the ECM.
      +RES Switch Outputs acceleration and resume stored speed signals to the ECM.
      -SET Switch Outputs deceleration and set vehicle speed signals to the ECM.
      Skid Control ECU Assembly

      • Sends VSC operation signals to the ECM.

      • Sends TRC operation signals to the ECM.

      • Sends signals such as wheel speed and estimated vehicle acceleration signals to the ECM.
      ECM Controls all functions of the cruise control system in accordance with the signals received from switches, sensors and ECUs.
      Combination Meter Assembly Cruise Control Indicator

      • Illuminates based on signals from the ECM when the cruise control system is turned on using the cruise control main switch.

      • Turns off based on signals from the ECM when a malfunction is detected in the cruise control system.
      Cruise Control SET Indicator Illuminates when the vehicle speed is set.
      Multi-information Display

      • Displays warning messages to alert the driver.

      • Displays the current set speed.
      Throttle Body Assembly Throttle Control Motor Adjusts the throttle valve opening angle in accordance with signals received from the ECM.
      Throttle Position Sensor Outputs the throttle valve opening angle to the ECM.
      Speed Sensor Outputs wheel speed signals to the skid control ECU assembly.
      Accelerator Pedal Sensor Assembly Outputs accelerator pedal depression angle to the ECM.
      VSC OFF Switch (No. 2 Combination Switch Assembly) Outputs VSC off signals to the skid control ECU assembly.
      Shift Control ECU Outputs the shift state signals to the ECM.
      Stop Light Switch Assembly Outputs brake pedal depressed signals to the ECM.

  3. OPERATION OF CRUISE CONTROL


    1. The cruise control system has the following control functions:

      Function Outline
      Constant Speed Control The ECM compares the actual vehicle speed and the set speed and if the vehicle speed is less than the set speed, it uses the throttle control motor to increase the throttle valve opening angle.
      Set Control The vehicle speed is stored and speed control is performed when the -SET switch is pushed while driving with the cruise control system on and the vehicle speed is within the set speed range. The current set speed is displayed on the multi-information display when the +RES switch or -SET switch is pushed.
      Low Speed Limit Control The low speed limit is the lowest speed that cruise control can be set at and it is designed to be approximately 40 km/h (25 mph). The cruise control system cannot be set below that speed. If the vehicle speed drops below that speed while the cruise control is operating, speed control by the cruise control system will be canceled automatically. However, the set speed is kept in memory.
      - (COAST) Control When the cruise control system is controlling vehicle speed and the -SET switch is pushed and held, the cruise control system sends a "throttle valve opening angle 0°" demand signal to the ECM. Following this, the vehicle speed is stored and maintained when the -SET switch is released.
      Tap-down Control When the cruise control system is controlling vehicle speed and the -SET switch is tapped (for approximately 0.6 seconds), the stored vehicle speed decreases by approximately 1 km/h or 1 mph for each time the switch is tapped. When the -SET switch is tapped and the difference between the current and stored vehicle speed is more than 5 km/h (3 mph), the current vehicle speed is stored and speed control is performed.
      + (ACCEL) Control When the cruise control system is controlling vehicle speed and the +RES switch is pushed and held, the cruise control system sends a signal to the ECM to operate the throttle valve motor of the throttle body with motor assembly to open the throttle valve. Following this, the vehicle speed is stored and maintained when the +RES switch is released.
      Tap-up Control When the cruise control system is controlling vehicle speed and the +RES switch is tapped (for approximately 0.6 seconds), the stored vehicle speed increases by approximately 1 km/h or 1 mph for each time the switch is tapped. When the +RES switch is tapped and the difference between the current and stored vehicle speed is more than 5 km/h (3 mph), the stored vehicle speed will not be changed.
      RES (Resume) Control If control of vehicle speed by the cruise control system was canceled due to any of the manual cancel conditions (other than turning the cruise control system off using the cruise control main switch), and if the vehicle speed is approximately 40 km/h (25 mph) or more, the stored vehicle speed from the time of cancellation will be resumed and maintained when the +RES switch is pushed.
      Manual Cancel Control

      Performing any of the following cancels the cruise control system control of vehicle speed (the stored vehicle speed in the ECM is maintained).


      • Depressing the brake pedal.

      • Moving the shift position from D to any other position.

      • Selecting the 3rd, 2nd or 1st range using the transmission shift switch assembly with the shift position in D.

      • Pushing the CANCEL switch.

      • Turning the cruise control system off using the cruise control main switch (the stored vehicle speed in the ECM is not maintained).
      Automatic Cancel Control

      This system has an automatic cancellation function (fail-safe).

      Click here

      Shift Down Control When the vehicle is traveling uphill using cruise control, automatic transmission control may cause the transmission to shift down. During shift down control, when the end of uphill travel is determined, the transmission will shift up after a certain period of time. When the transmission shifts down during the accelerator control or the resume control, the transmission will shift up after the accelerator control or the resume control ends.