CRUISE CONTROL SYSTEM DETAILS


  1. FUNCTION OF MAIN COMPONENTS


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

      Component Function
      Cruise Control Main Switch ON-OFF Button Turns the power to the cruise control system on and off.
      CANCEL Switch A cancel signal can be output to the power management control ECU through the operation of this switch.
      +RES Switch The accelerate function and resuming of a preset speed can be performed by operating this switch. A signal is output to the power management control ECU when this switch is operated.
      -SET Switch The decelerate function and vehicle speed setting resume signals are output to the power management control ECU due to operation of this switch.
      Power Management Control ECU Controls all functions of the cruise control system in accordance with the signals from switches, sensors and ECUs.
      MG ECU Built into the inverter with converter assembly. Controls the motive force of the MG2 in accordance with signals from the power management control ECU.
      ECM Actuates the throttle control motor in accordance with the signals from the power management control ECU.
      Skid Control ECU Transmits the wheel speed signal and VSC operation signal to the power management control ECU.
      Combination Meter Assembly Cruise Main Indicator Light

      • Illuminates when the cruise control system is in standby or cruise control is activated.

      • Blinks if a malfunction occurs during cruise control driving.
      Cruise SET Indicator Light Illuminates when the vehicle speed is set.
      MG2 Generates the motive force for the wheels.
      Throttle Control Motor Adjusts the throttle valve opening angle in accordance with signals from the ECM.
      Speed Sensor Detects the wheel speed of each of 4 wheels.
      Accelerator Pedal Position Sensor Detects the accelerator pedal depression degree and outputs it to the power management control ECU.
      Shift Lever Position Sensor Detects the shift position and transmits signals to the power management control ECU.
      Stop Light Switch Detects the brake pedal being depressed and transmits its signal to the power management control ECU.

  2. FUNCTION


    1. The cruise control has the following control functions.

      Function Outline
      Constant Speed Control The power management control ECU compares the actual vehicle speed with the set speed. If the vehicle speed is higher than the set speed, the power management control ECU calculates optimal motive forces for the engine and MG2, and decelerates by adjusting the respective motive forces. If the vehicle speed is lower than the set speed, the power management control ECU calculates optimal motive forces for the engine and MG2, and accelerates by adjusting the respective motive forces.
      Set Control

      • When this system fulfils the following conditions, and the cruise control main switch is moved to the -SET side and released, the power management control ECU stores the vehicle speed and illuminates the cruise SET indicator light on the combination meter assembly and maintains the vehicle constantly at that speed.


        • ON-OFF button on the cruise control main switch is pressed.

        • The vehicle is running at an approximate speed of between 40 km/h (25 mph) and 200 km/h (125 mph).
      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 cannot be set below that speed. If the vehicle speed drops below that speed while running in the cruise control, the cruise control will be cancelled automatically. However the set speed is kept in memory.
      COAST (-) Switch Control

      • When the cruise control main switch is held to the -SET side, the vehicle speed and the set vehicle speed change as follows:


        • The vehicle will decelerate.

        • The set vehicle speed will change to the speed that the vehicle is traveling at when the COAST switch (-SET side operation) is released.
      Tap Down Control

      • When the cruise control main switch is moved momentarily (approximately 0.6 seconds or less) to the -SET side, the vehicle speed and the set vehicle speed change as follows:


        • The vehicle will decelerate in increments of approximately 1.6 km/h (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 was traveling at when the switch was released.
      ACC (+) Switch Control

      • When the cruise control main switch is held to the +RES side, the vehicle speed and the set vehicle speed change as follows:


        • The vehicle will accelerate.

        • The set vehicle speed will change to the speed at which the vehicle was being driven at the time the switch was released.
      Tap Up Control

      • When the cruise control main switch is moved momentarily (approximately 0.6 seconds or less) to the +RES side, the vehicle speed and the set vehicle speed change as follows:


        • The vehicle will accelerate in increments of approximately 1.6 km/h (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.
      RES Switch Control If the cruise control is canceled for any reason other than a malfunction (except cancellation by operating the ON-OFF button on the cruise control main switch) and the vehicle speed is more than the low speed limit, the vehicle can be returned to the speed which was before the cancellation of cruise operation by moving the cruise control main switch to the +RES side. The cruise control mode can be resumed even if the vehicle speed drops below the low speed limit, because the speed in the memory has not been cleared.
      Manual Cancel Control

      • If any of the following signals are sent to the power management control ECU, the cruise control is cancelled accordingly.


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

        • D position circuit in the shift lever position sensor off signal (The shift lever is moved from D to N or B.)

        • CANCEL switch on signal (The cruise control main switch is moved to the CANCEL side.)

        • Cruise control main switch (ON-OFF button) off signal

        • VSC operation
      Automatic Cancel Control

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


        • Stop light switch open or short circuit


      • Furthermore, the cruise main indicator light will blink until the ON-OFF button on the cruise control main switch is used to turn the system off, and the operation of the cruise control will be disabled until the ON-OFF button is turned on again.

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


        • Malfunction in the hybrid system


      • Furthermore, the operation of the cruise control will be disabled until the ON-OFF button is turned on again.

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


        • Stop light switch input signal is abnormal.

        • Cancel circuit malfunction

        • Brake control system malfunction

        • Communication malfunction between the skid control ECU and power management control ECU


      • Furthermore, the cruise main indicator light will blink until the ON-OFF button on the cruise control main switch is used to turn the system off, and the operation of the cruise control will be disabled until the power switch is turned off.

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


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

      • If the following condition occurs during cruise control operation, the cruise control is cancelled.


        • Vehicle speed is below the low speed limit (approximately 40 km/h [25 mph]).

  3. CONSTRUCTION


    1. Cruise Control Main Switch


      1. The cruise control main switch consists of the ON-OFF button, +RES, -SET and CANCEL switches. The +RES, -SET and CANCEL switches are operated by moving the lever in the 3 directions indicated.

      2. The cruise control main switch is an automatic reset (normally open) type that turns on only when the switch is being operated and turns off as soon as the driver releases the switch. Furthermore, the functions of the control switch are active only when the cruise control system has been turned on using the ON-OFF button on the cruise control main switch.

        A01J8A1E01
        Text in Illustration
        *1 Cruise Control Main Switch - -
        *a ON-OFF Button *b +RES Switch
        *c -SET Switch *d CANCEL Switch

  4. OPERATION


    1. Combination Meter Assembly


      1. The combination meter assembly provides a cruise main indicator light and cruise SET indicator light to indicate in the cruise control system.

        Condition A01J7RH A01J885
        Set Standby Illuminates -
        Being Controlled Illuminates Illuminates
        System Malfunction Blinks -

  5. DIAGNOSIS


    1. If a malfunction occurs in the cruise control system during cruise control operation, the power management control ECU automatically cancels control and blinks the cruise main indicator light to inform the driver of the malfunction. At this time, the power management control ECU stores the malfunction in the form of 5-digit Diagnostic Trouble Code (DTC).

    2. The 5-digit DTC can be read by connecting the intelligent tester to DLC3. For details, refer to the Repair Manual.