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 Switch ON-OFF Button Turns the cruise control system on and off.
      CANCEL Switch A cancel signal is output to the power management control ECU when this switch is operated.
      +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 set 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.
      Inverter with Converter Assembly MG ECU Built into the inverter with converter assembly. Controls the motive force of 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.
      Brake Booster with Master Cylinder Assembly Skid Control ECU Transmits the wheel speed signal and VSC operation signal to the power management control ECU.
      Combination Meter Assembly Cruise Control 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 Control SET Indicator Light Illuminates when the vehicle speed is set.
      Throttle Body Assembly Throttle Control Motor Adjusts the throttle valve opening angle in accordance with signals from the ECM.
      Throttle Position Sensor Detects the throttle valve opening angle and outputs it to the ECM.
      Hybrid Vehicle Transaxle Assembly MG2 Generates motive force for the wheels in conjunction with the engine.
      Speed Sensors Detects the wheel speed of each of the 4 wheels.
      Accelerator Pedal Sensor Assembly Detects the accelerator pedal depression degree and transmits it to the power management control ECU.
      Shift Lock Control Unit Assembly Shift Lever Position Sensor (Shift Sensor) Detects the shift position and transmits signals to the power management control ECU.
      Shift Lever Position Sensor (Select Sensor)
      Stop Light Switch Assembly 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 fulfills the following conditions, and the cruise control switch is moved to the -SET side and released, the power management control ECU stores the vehicle speed and illuminates the cruise control SET indicator light on the combination meter assembly and maintains the vehicle constantly at that speed.


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

        • The vehicle is driving at an approximate speed of between 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 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 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 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 approximately 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 pushed.
      ACC (+) Switch Control

      • When the cruise control 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 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 approximately 5 km/h (3 mph), the set vehicle speed will not change.
      RES Switch Control If the operation of cruise control is canceled for any reason other than a malfunction (except cancellation by operating the ON-OFF button on the cruise control switch) and the vehicle speed is more than the low speed limit, the vehicle can be returned to the speed stored before the cancellation of cruise operation by moving the cruise control switch to the +RES side. The cruise control mode can be resumed even if the vehicle speed dropped below the low speed limit because the speed in memory is not cleared.
      Manual Cancel Control

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


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

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

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

        • Cruise control 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 memory is cleared and the operation of cruise control is canceled.


        • Stop light switch open or short circuit.


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

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


        • Malfunction in the hybrid system.


        • An abnormal signal is detected from the yawrate sensor or the speed sensor.


      • Furthermore, cruise control operation is disabled until the cruise control system is turned on again using the ON-OFF button.

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


        • 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 control indicator light will blink until the ON-OFF button on the cruise control 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 memory is cleared and the operation of cruise control is canceled.


        • Vehicle speed decreases by approximately 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 operation of cruise control canceled.


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

  3. CONSTRUCTION


    1. Cruise Control Switch


      1. The cruise control 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 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 switch.

        A01LPBQE01
        Text in Illustration
        *1 Cruise Control 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 control indicator light and cruise control SET indicator light to indicate the status of the cruise control system.

        Condition A01LPGG A01LPCW
        Set Standby Illuminates Does not illuminate
        Being Controlled Illuminates Illuminates
        System Malfunction Blinks Does not illuminate

  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 control 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 Global TechStream (GTS) to DLC3. For details, refer to the Repair Manual.