CRUISE CONTROL SYSTEM DETAILS


  1. 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 opening.
      Set Control

      When the vehicle has met the following condition, and the cruise control switch is pressed to the -/SET side and released after the ON-OFF button on the cruise control switch is pressed to turn the system on, the ECM will store the vehicle speed and then maintain the vehicle constantly at that speed.


      • The vehicle is running at a speed of about 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 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 changes to the speed at which the vehicle was traveling at when the COAST switch (-/SET side operation) was released.
      Tap Down Control

      When the cruise control switch is pushed momentarily (approximately 0.6 second) to the -/SET side, the vehicle speed and the vehicle set speed change as follows:


      • The vehicle will decelerate in increments of approximately 1.6 km/h (1 mph) each time the switch is pressed.

      • However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3.1 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 changes to the speed at which the vehicle was traveling at when the switch was released.
      Tap Up Control

      When the cruise control switch is pushed momentarily (approximately 0.6 second) 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 pressed.

      • However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3.1 mph), the set vehicle speed will not change.
      RES Switch Control If cruise control is canceled for any reason other than a malfunction or cruise control switch 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 pushing the cruise control 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 memory is not cleared.
      Automatic Transmission Control When the vehicle is cruising uphill, the overdrive may turn off depending on Electronic Control Transmission (ECT) control. After the ECM judges that cruising uphill has ended (based on the throttle valve angle), the overdrive function will turn on again. There may be cases where the overdrive turns off when ACC or RES switch is used.
      Manual Cancel Control

      If any of the following signals are sent to the ECM, the cruise control will be canceled accordingly.


      • Shift lever is shifted from D to N.

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

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

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

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

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


      • Stop light switch assembly open or short circuit

      • The vehicle speed signal is not input for a predetermined period of time (approximately 140 msec).

      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 ON-OFF button is turned on again.

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


      • ETCS-i malfunction

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

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


      • Stop light switch assembly input signal will be abnormal.

      • Cancel circuit malfunction.

      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 next time the ignition switch is turned to ON.

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


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

      If either of the following conditions occur during cruise control operation, the cruise control will be canceled.


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

      • VSC operation
      Diagnosis If the ECM does not receive a vehicle speed signal for a predetermined period of time during cruising, or if cruise control is canceled (automatic cancel) due to a malfunction of the cruise control, stop light switch assembly or vehicle speed signal, the ECM immediately blinks the cruise control indicator light due to the malfunction. The information relating to the malfunction will be stored in the ECM.

  2. DIAGNOSIS


    1. If a malfunction occurs in the cruise control system during cruise control operation, the ECM cancels the cruise control and blinks the cruise control indicator light to inform the driver of the malfunction. At this time, the ECM memorizes 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 the DLC3. For details, refer to the Repair Manual.