CRUISE CONTROL SYSTEM


  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 hybrid vehicle control ECU assembly 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 hybrid vehicle control ECU assembly when this switch is operated.
      -SET Switch The deceleration function and vehicle speed setting resume signals are output to the hybrid vehicle control ECU when this switch is operated.
      Hybrid Vehicle Control ECU Assembly Controls all functions of the cruise control system in accordance with the signals from switches, sensors and ECUs.
      Inverter with Converter Assembly MG ECU Controls the motive force of MG2 in accordance with the signals from the hybrid vehicle control ECU assembly.
      Hybrid Vehicle Transmission Assembly MG2 Generates motive force for the wheels.
      Skid Control ECU Assembly

      • Transmits the wheel speed signal to the hybrid vehicle control ECU assembly.

      • Transmits the VSC operation signal to the hybrid vehicle control ECU assembly.
      ECM Controls the throttle control motor in accordance with the signals from 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 ON-OFF button on the cruise control switch.

      • 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 if a malfunction occurs in the cruise control system.
      Cruise SET Indicator Cruise SET indicator Illuminates when the vehicle speed is set.
      Multi-information Display Displays a warning message to alert the driver in accordance with a signal provided by the hybrid vehicle control ECU assembly.
      Master Warning Light Comes on when there is a malfunction in the system.
      Throttle Body with Motor 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.
      Speed Sensors Detects the wheel speed of each of the 4 wheels.
      Accelerator Pedal Sensor Assembly Detects the accelerator pedal depression angle and transmits it to the hybrid vehicle control ECU assembly.
      Stop Light Switch Assembly Detects the brake pedal being depressed and transmits its signal to the hybrid vehicle control ECU assembly.
      Shift Lever Position Sensor

      • Detects the shift lever position and transmits signals to the hybrid vehicle control ECU assembly.

      • Detects the shift lever is moved from D to S and transmits signals to the hybrid vehicle control ECU assembly.
      Shift Paddle Switch (Transmission Shift Switch Assembly) While the vehicle is being driven in D mode, this switch outputs a signal to the hybrid vehicle control ECU assembly when the switch is pulled to "+" or "-".

      Transmission Floor Shift Assembly


      • Transmission Control Switch

      		 While the vehicle is being driven in S mode, this switch outputs a signal to the hybrid vehicle control ECU assembly. when the shift lever is moved toward "+" or "-".

      Combination Switch Assembly


      • VSC OFF Switch

      		 Detects the VSC OFF or TRC OFF signal and outputs it to the skid control ECU assembly.

  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 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 hybrid vehicle control ECU assembly 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 switch is moved to the -SET side 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 ON-OFF button on the cruise control switch.

      • The vehicle is being driven at a speed of approximately 40 km/h (25 mph) to 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 the cruise control is operating, the cruise control will be canceled 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 at which the vehicle is being driven 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 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.
      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 is being driven when the switch is 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 5 km/h (3 mph), the set vehicle speed will not change.
      RES Switch Control If speed control by the cruise control system is canceled for any reason other than a malfunction (except cancelation 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 which was stored before the cancelation of cruise control operation by moving the cruise control switch to the +RES side. The stored vehicle speed can be resumed even if the vehicle speed drops below the low speed limit, because the speed in memory has not been cleared.
      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 on signal (The brake pedal is depressed).

      • Shift lever is moved from D or S to any other position.

      • When 1st, 2nd or 3rd range is selected in D or S position by shift paddle switch (transmission shift switch assembly).

      • When 1st, 2nd or 3rd shift range is selected manually while in S.

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

      • Cruise control switch (ON-OFF button) off signal.
      Automatic Cancel Control

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


      • Stop light switch open or short circuit.

      Furthermore, the master warning light illuminates, 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 switch. The operation of the cruise control is disabled until the cruise control system is turned on again using the ON-OFF button.

      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 ON-OFF button.

      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 input signal is abnormal.

      • Cancel circuit malfunction.

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

      • Brake control system malfunction.

      Furthermore, the master warning light illuminates, 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 switch. The operation of the cruise control is disabled until the power switch is turned off.

      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.


      • 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 during cruise control speed control operation, speed control by the cruise control system is canceled.


      • Vehicle speed decreases below the low speed limit (approximately 40 km/h [25 mph]).
      Other Cancellation Items

      • VSC is activated.

      • TRC is activated for a period of time.

      • When the VSC or TRC system is turned off by pressing the VSC OFF switch.

  3. DIAGNOSIS


    1. If a malfunction occurs in the cruise control system during cruise control operation, the hybrid vehicle control ECU assembly cancels cruise control operation, illuminates the master warning light and turns off the cruise control indicator and cruise control SET indicator. At this time, "Cruise Control Malfunction Visit Your Dealer" is displayed on the multi-information display. The hybrid vehicle control ECU assembly stores the malfunction in the form of a 5-digit Diagnostic Trouble Code (DTC).

    2. The 5-digit DTC can be read by connecting the Global TechStream (GTS) to the DLC3. For details, refer to the Repair Manual.