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 Assembly ON-OFF Button Turns the power to the cruise control system on/off.
      CANCEL Switch A cancel signal can be output to the ECM through the operation of this switch.
      +RES Switch The acceleration function and resumption 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 deceleration function and vehicle speed setting resume signals are output to the ECM due to operation of this switch.
      ECM Increases and decreases the motive force.
      TCM Controls the transmission gear selection in accordance with signals transmitted by the ECM.
      Skid Control ECU Assembly Transmits signals about the wheel speed and estimated vehicle acceleration to the ECM.
      Combination Meter Assembly Cruise Control Main Indicator Light

      • Illuminates when the constant speed mode is on.

      • Turns off if the ECM detects a malfunction.
      Cruise Control SET Indicator Light Illuminates when the constant speed control mode or the vehicle-to-vehicle distance control mode is set.
      Throttle Control Motor

      • Adjusts the throttle valve opening angle in accordance with signals from the ECM. (Throttle Control Motor)

      • Detects the throttle valve opening angle and outputs it to the ECM. (Throttle Position Sensor)
      Accelerator Pedal Sensor Assembly Detects the accelerator pedal depression degree and outputs it to the ECM.
      Park/Neutral Position Switch Assembly Converts the shift position into an electrical signal and outputs it to the ECM.
      Stop Light Switch Assembly Detects the pressing of the brake pedal and transmits a signal to the ECM.
      Combination Switch Assembly (SNOW Mode Switch) Transmits SNOW mode switch information to the ECM via the driver side switch module (outer mirror switch assembly).
      Transmission Floor Shift Assembly (Transmission Control Switch) While the vehicle is being driven in S mode*1 or M mode*2, this switch outputs a signal to the ECM if the shift lever is moved towards "+" or "-".
      Paddle Shift Switch (Transmission Shift Switch Assembly)*2 While the vehicle is being driven in D mode or M mode, this switch outputs a signal to the ECM if the switch is pulled "+" or "-".

      • *1: Models without paddle shift switch (transmission shift switch assembly)

      • *2: Models with paddle shift switch (transmission shift switch assembly)

  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 higher than the set speed, it reduces the motive force. Conversely, if the actual vehicle speed is lower than the set speed, the ECM increases the motive force.
      Set Control

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

      • The vehicle is running at a vehicle speed of approx. 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 approx. 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 canceled automatically. However, the set speed in the memory is kept.
      High Speed Limit Control

      The high speed limit is the highest speed that cruise control mode can be set and is designed at approx. 200 km/h (125 mph).


      • The cruise control mode cannot be set if the vehicle speed exceeds the high speed limit.

      • The vehicle does not accelerate when the +RES switch is operated if the vehicle speed exceeds the high speed limit.
      Coast Switch Control

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


      • The vehicle decelerates constantly.

      • The set vehicle speed changes to the speed that the vehicle is traveling at when the COAST switch is released.
      Tap Down Control

      When the cruise control main switch assembly is pushed momentarily (approx. 0.5 sec.) to the -SET side, the vehicle speed and the vehicle setting speed change as follows:


      • The vehicle decelerates in increments of approx. 1.6 km/h (1 mph) for each time the switch is pressed.

      • However, if the difference between the actual vehicle speed and the vehicle setting speed is greater than 5 km/h (3.1 mph), the vehicle setting speed changes to the speed at which the vehicle was being driven at the time the switch is operated.
      Accelerator Switch Control

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


      • The vehicle accelerates constantly.

      • The set vehicle speed changes to the speed as which the switch is releases.
      Tap Up Control

      When the cruise control main switch assembly is pushed momentarily (approx. 0.5 sec.) to the +RES side, the vehicle speed and the vehicle setting speed change as follows:


      • The vehicle accelerates in increments of approx. 1.6 km/h (1 mph) for each time the switch is pressed.

      • However, if the difference between the actual vehicle speed and the vehicle setting speed is greater than 5 km/h (3.1 mph), the vehicle setting speed does not change.
      Resume Switch Control If cruise control is canceled for any reason other than a malfunction or cruise control main switch assembly operation and vehicle speed is more than the low speed limit, the vehicle speed is returned to the speed before the cancellation of cruise operation by setting the cruise control main switch assembly 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 is not cleared.
      Shift Down Control When the vehicle is cruising uphill, shift-down control may be performed by the TCM. The ECM transmits the shift up request signal to the TCM when the ECM judges the end of cruising uphill based on the throttle valve angle. If shift-down control is performed during ACC or RES switch control, the ECM transmits the shift up request signal to the TCM after ACC or RES switch control is completed.
      Manual Cancel Control

      If any of the following signals is sent to the ECM, the cruise control is canceled accordingly:


      • Stop light switch assembly on signal/Depress the brake pedal

      • Shift lever is moved from D to N.

      • When 1st, 2nd or 3rd range is selected in S*1 or M*2 mode position.

      • When 1st, 2nd or 3rd range is selected in D mode position.*2

      • CANCEL switch on signal (cruise control main switch assembly moved to CANCEL side)

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

      When 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 canceled:


      • The stop light switch has an assembly open or short circuit.

      • The vehicle speed signal is not input for a predetermined period of time.

      • Malfunction of the throttle control system.

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

      When any of the following conditions occur during cruise control driving, the speed that is set in the memory is cleared and the cruise control is canceled:


      • The stop light switch assembly input signal is abnormal.

      • The cancel circuit malfunctions

      Furthermore, the cruise control main indicator light will turns off until the ON-OFF button on the cruise control main switch assembly is used to turn the system off, and the operation of the cruise control is disabled until the power source is turned on (IG) again.

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


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

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


      • VSC operates during cruise control driving.

      • TRC operates for a certain period of time during cruise control driving.

      • TRC is off or VSC is off.
      Diagnosis When the ECM does not receive a vehicle speed signal for a predetermined period of time during cruising, or when cruise control is canceled (automatic cancel) due to a malfunction in the cruise control, stop light switch assembly, skid control ECU assembly or vehicle speed signals, it immediately turns off the cruise control main indicator light to indicate occurrence of any malfunctions. The contents related to the malfunction are stored in the ECM.

      • *1: Models without paddle shift switch (transmission shift switch assembly)

      • *2: Models with paddle shift switch (transmission shift switch assembly)