CRUISE CONTROL SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Steering Pad Switch Assembly Cruise Control Main Switch Turns on/off the power to the cruise control system.
    -SET Switch The deceleration function and set control function can be performed by operating this switch. A signal is sent to the hybrid vehicle control ECU assembly when this switch is operated.
    +RES Switch The acceleration function and resume control function can be performed by operating this switch. A signal is sent to the hybrid vehicle control ECU assembly when this switch is operated.
    CANCEL Switch A cancel signal can be sent to the hybrid vehicle control ECU assembly through the operation of this switch.
    Throttle Body with Motor Assembly Throttle Control Motor Adjusts the throttle valve to the limiter position in accordance with signals from the ECM.
    Throttle Position Sensor Transmits the throttle valve position information to the ECM.
    Stop Light Switch Assembly Detects the depressing of the brake pedal and transmits a signal to the hybrid vehicle control ECU assembly.
    Combination Meter Assembly Cruise Control Indicator

    • Based on a cruise control indicator operation signal sent by the hybrid vehicle control ECU assembly, the combination meter assembly illuminates the cruise control indicator when the cruise control system has been turned on using the cruise control main switch on the steering pad switch assembly.

    • Based on a cruise control indicator operation signal sent by the hybrid vehicle control ECU assembly, the combination meter assembly turns off the cruise control indicator light if a malfunction occurs in the cruise control system.
    Cruise Control SET Indicator Illuminates when the vehicle speed is set.
    Multi-information Display During cruise control operation, the multi-information display receives signals from the hybrid vehicle control ECU assembly in order to display the system conditions.
    Master Warning Light Illuminates when there is a malfunction in the cruise control system.
    Meter Buzzer Sounds to warn the driver of a malfunction in the cruise control system.
    Hybrid Vehicle Control ECU

    • Controls the cruise control system in accordance with signals from the switches and sensors.

    • If the hybrid vehicle control ECU detects a malfunction in the cruise control system, it will store a Diagnostic Trouble Code (DTC).
    Accelerator Pedal Sensor Assembly Detects the accelerator pedal depression degree and sends it to the hybrid vehicle control ECU assembly.
    ECM Actuates the throttle control motor in accordance with the signals from the hybrid vehicle control ECU assembly.
    Inverter with Converter Assembly MG ECU Controls the motive force of the hybrid vehicle transmission assembly in accordance with signals from the hybrid vehicle control ECU assembly.
    Hybrid Vehicle Transmission Assembly Generates motive force for the rear wheels.
    Skid Control ECU Assembly

    • Sends a vehicle speed signal to the hybrid vehicle control ECU assembly.

    • Sends the VSC and TRC control status to the hybrid vehicle control ECU assembly.
    Headup Display (Meter Mirror Sub-assembly)* The headup display receives signals from the hybrid vehicle control ECU assembly in order to display the system conditions.
    Central Gateway ECU (Network Gateway ECU) Transmits the signal between the CAN communication buses.
    DLC3 The Global TechStream (GTS) can be connected to read the Diagnostic Trouble Codes (DTCs) of malfunctions.

    *: Models with headup display

  2. FUNCTION


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

      Function Outline
      Constant Speed Control The hybrid vehicle control ECU assembly compares the actual vehicle speed with the set speed. If the vehicle speed is higher than the set speed, the hybrid vehicle control ECU assembly calculates the optimal motive forces, and decelerates by adjusting the respective motive forces. If the vehicle speed is lower than the set speed, the hybrid vehicle control ECU assembly calculates the optimal motive forces, and accelerates by adjusting the respective motive forces.
      Set Control

      When this system fulfils the following conditions, and the -SET switch on the steering pad switch assembly is pressed and released, the hybrid vehicle control ECU assembly stores the vehicle speed and maintains the vehicle constantly at that speed.


      • The cruise control system has been turned on using the cruise control main switch on the steering pad switch assembly.

      • The vehicle is driving at a speed of approximately 40 km/h (25 mph) or more.
      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

      While the -SET switch on the steering pad switch assembly is pushed continuously, the vehicle speed and the set vehicle speed change as follows:


      • The vehicle decelerates constantly.

      • The set vehicle speed changes to the speed at which the -SET switch is released.
      Tap Down Control

      When the -SET switch on the steering pad switch assembly is pushed momentarily (approximately 0.6 seconds or less), the vehicle speed and the set vehicle speed change as follows:


      • The vehicle will decelerate in increments of approximately 1 km/h or 1 mph each time the switch is moved.

      • However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3 mph), the set vehicle speed will change to the speed at which the vehicle is being driven when the switch is pushed.
      Accelerator Control

      While the +RES switch on the steering pad switch assembly is pushed continuously, the vehicle speed and the set vehicle speed change as follows:


      • The vehicle accelerates constantly.

      • The set vehicle speed changes to the speed at which the +RES switch is released.
      Tap Up Control

      When the +RES switch on the steering pad switch assembly is pushed momentarily (approximately 0.6 seconds or less), the vehicle speed and the set vehicle speed change as follows:


      • The vehicle will accelerate in increments of approximately 1 km/h or 1 mph each time the switch is moved.

      • However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3 mph), the set vehicle speed will not change.
      Resume Control When the vehicle speed is above the low speed limit, the cruise control system resumes operation (when the +RES switch on the steering pad switch assembly is pushed) to reach the vehicle speed that was set at the time the driver canceled cruise control. Even if the vehicle speed dropped below the low speed limit, the set speed can be resumed after the vehicle speed increases above the low speed limit. Also, if the vehicle speed memory is deleted, the return control cannot be performed.
      Manual Cancel Control

      If any of the following signals are sent to the hybrid vehicle control ECU assembly, speed control by the cruise control system is canceled accordingly.


      • Stop light switch assembly on signal (the brake pedal is depressed).

      • Shift position is changed from D to any other position.

      • Cruise control main switch off signal.

      • CANCEL switch on signal (CANCEL switch on the steering pad switch assembly is pushed).
      Automatic Cancel Control

      If the following condition occurs during cruise control speed control operation, the speed that is set in memory is cleared and cruise control speed control operation is canceled.


      • Stop light switch assembly open or short circuit

      Furthermore, the master warning light illuminates, the cruise control indicator turns off, and a message indicating a malfunction will be displayed on the multi-information display until the cruise control system is turned off using the cruise control main switch on the steering pad switch assembly. The operation of the cruise control is disabled until the cruise control system is turned on again using the cruise control main switch on the steering pad switch assembly.

      If the following condition occurs during cruise control speed control operation, the speed that is set in memory is cleared and cruise control speed control operation is canceled.


      • Malfunction in the hybrid system

      Furthermore, speed control by the cruise control system is disabled until the cruise control system is turned on again using the cruise control main switch on the steering pad switch assembly.

      If any of the following conditions occur during cruise control speed control operation, the speed that is set in memory is cleared and cruise control speed control operation is canceled.


      • Stop light switch assembly input signal is abnormal.

      • Cancel circuit malfunction.

      • Brake control system malfunction.

      • Communication malfunction between the skid control ECU assembly and hybrid vehicle control ECU assembly.

      Furthermore, the master warning light illuminates, the cruise control indicator light turns off, and a message indicating a malfunction will be displayed on the multi-information display until the cruise control system is turned off using the cruise control main switch on the steering pad switch assembly. The operation of the cruise control is disabled until the power switch is turned off.

      If the following condition occurs while the cruise control system is controlling the vehicle speed, the speed that is stored in memory is cleared and speed control by the cruise control system is canceled.


      • Vehicle speed decreases by 16 km/h (10 mph) or more below the speed at which the cruise control is set.

      If the following condition occurs while the cruise control system is controlling the vehicle speed, speed control by the cruise control system is canceled.


      • Vehicle speed decreases below the low speed limit approximately 40 km/h (25 mph).
      Other Cancel Conditions

      • If any of the following conditions occur during cruise control driving, the cruise control is canceled. However, the set speed remains in the memory.


        • The VSC system is activated.

        • The TRC system is activated for a period of time.

        • The VSC or TRC system is turned off.

      • When the power switch is turned off, the set speed is not stored in the memory.

    2. Cruise Control Operation Switch


      1. The operation switches of the cruise control system (cruise control main switch, -SET switch, +RES switch and CANCEL switch) are positioned in the steering pad switch assembly.

        Component Function
        Cruise Control Main Switch Turns the cruise control system on and off.
        +RES Switch Performs accelerator control, tap-up control and resume control.
        -SET Switch Performs set control, coast control and tap-down control.
        CANCEL Switch Cancels control.
        A004C5FC01
        *1 CANCEL Switch *2 -SET Switch
        *3 Cruise Control Main Switch *4 +RES Switch

  3. DIAGNOSIS


    1. If a malfunction occurs in the cruise control system, the hybrid vehicle control ECU assembly cancels the cruise control system. The hybrid vehicle control ECU assembly turns off the cruise control indicator and a message indicating a malfunction will be displayed on the multi-information display to inform the driver of a malfunction. At this time, the hybrid vehicle control ECU assembly memorizes the malfunction in the form of a 5-digit Diagnostic Trouble Code (DTC). For details on the DTC, refer to the Repair Manual.