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 Main Switch ON-OFF Button Turns the cruise control system on and off.
      CANCEL Switch A cancel signal is output to the ECM 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 ECM when this switch is operated.
      -SET Switch The decelerate function and vehicle speed setting signals are output to the ECM when this switch is operated.
      Brake Actuator Assembly Skid Control ECU

      • Transmits the wheel speed signal to the ECM.

      • Transmits the VSC operation signal to the ECM.
      ECM Controls all functions of the cruise control system in accordance with the signals from switches, sensors and ECUs.

      Combination Meter Assembly


      • Multi-information Display

      		 Cruise Control Indicator Light

      • Based on a cruise control indicator light operation signal sent by the ECM, the combination meter assembly illuminates the cruise control indicator light when the cruise control system has been turned on using the ON-OFF button on the cruise control main switch.

      • Based on a cruise control indicator light operation signal sent by the ECM, the combination meter assembly turns off the cruise control indicator light if a malfunction occurs in the cruise control system.
      Cruise SET Indicator Light Illuminates when the vehicle speed is set.
      Multi-information Display Displays a warning message to alert the driver in accordance with a signal received from the ECM.
      Buzzer If the ECM detects automatic cancel or warning signals while the vehicle is operating under cruise control, this buzzer sounds to inform the driver.
      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 Sensor Detects the wheel speed and transmits signals to the skid control ECU.
      Accelerator Pedal Sensor Assembly Detects the accelerator pedal depression angle and transmits it to the ECM.
      Clutch Pedal Stroke Sensor Assembly*1 Detects the depressing of the clutch pedal and transmits a signal to the ECM.
      Park/Neutral Position Switch Assembly*2 Detects the shift lever position and transmits signals to the ECM.
      Electric Parking Brake Switch Assembly VSC OFF (TRC OFF) Switch Detects the VSC (TRC) off signal and outputs it to the skid control ECU.
      Shift Lock Control Unit Assembly*2 Transmission Control Switch Detects the shift lever position and transmits signals to the ECM.
      Stop Light Switch Assembly Detects the brake pedal being depressed and transmits its signal to the ECM.
      Network Gateway ECU Relays and transmits each CAN communication data signal.

      *1: Models with manual transaxle

      *2: Models with CVT

  2. FUNCTION


    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 lower than the set speed, it uses the throttle control motor to increase the throttle valve opening angle.
      Set Control

      When this system fulfills the following conditions, and the cruise control main switch is moved to the -SET side and released, the ECM 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 main switch.

      • The vehicle is driving at a speed within the range of approximately 40 to 200 km/h (25 to 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 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 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 at which the vehicle is being driven 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 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.
      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 is being driven when the switch is 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 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.
      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 main 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 main 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 ECM, speed control by the cruise control system is canceled accordingly.


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

      • Clutch switch assembly on signal (depress the clutch pedal).*1

      • Shift lever is moved from D to any other position.*2

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

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

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


      • Stop light switch open or short circuit

      Furthermore, the master warning light illuminates, 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. 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 while the cruise control system is controlling vehicle speed, the speed that is set in memory is cleared and speed control by the cruise control system is canceled.


      • Malfunction is detected in SFI 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 while the cruise control system is controlling vehicle speed, the speed that is set in memory is cleared and speed control by the cruise control system is canceled.


      • Stop light switch assembly input signal is abnormal

      • Cancel circuit malfunction

      • Brake control system malfunction

      • Communication malfunction between the skid control ECU and ECM.

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

      If the following condition occurs while the cruise control system is controlling 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 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

      • 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 (TRC OFF) switch.

      • Ignition switch off.

      *1: Models with manual transaxle

      *2: Models with CVT

  3. DIAGNOSIS


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

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