CRUISE CONTROL SYSTEM DETAILS


  1. FUNCTION


    1. The cruise control 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 main switch is pressed to the -/SET side and released after the ON-OFF button on the cruise control main 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 stored vehicle speed and SET are indicated on the multi-information display.


      • The vehicle is running at a 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 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 that the vehicle is traveling at when the COAST switch (-/SET side operation) is released.
      Tap Down Control

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


      • The vehicle will decelerate in increments of approx. 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 when the switch was released.
      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 was being driven at the time the switch was released.
      Tap Up Control

      When the cruise control main switch is pushed momentarily (approx. 0.6 sec.) to the +/RES side, the vehicle speed and the set vehicle speed change as follows.


      • The vehicle will accelerate in increments of approx. 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 main switch operation and vehicle speed is more than the low speed limit, the vehicle speed is returned to the speed stored before the cancellation of cruise operation by pushing the cruise control main 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.
      Automatic Transmission Control When the vehicle is cruising uphill, the overdrive may turn off depending on ECT (Electronic Control Transmission) 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 one of the following conditions are met, the cruise control is canceled accordingly.


      • The shift lever is moved from D to N.

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

      • When 1st, 2nd or 3rd shift range is selected in D position by shift paddle switch.*

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

      • CANCEL switch ON signal sent to ECM. (cruise control main switch is moved to the CANCEL side)

      • Cruise control switch (ON-OFF button) OFF signal sent to ECM.
      Automatic Cancel Control

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


      • Stop light switch open or short circuit

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

      Furthermore, the cruise main indicator light turns off until the ON-OFF button on the cruise control main switch is used to turn the system off, and the operation of the cruise control 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 will be cleared and the cruise control will be canceled.


      • ETC-i malfunction

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

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


      • Stop light switch input signal is abnormal.

      • Cancel circuit malfunction.

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

      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 one of the following conditions occurs during cruise control operation, the cruise control is canceled.


      • Vehicle speed is below the low speed limit [approx. 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 cancellation) due to a malfunction of the cruise control, stop light switch circuit or vehicle speed signal, the ECM immediately illuminates the master warning light, sounds a buzzer and displays a message on the multi-information display. The information relating to the malfunction will be stored in the ECM.

      • *: F SPORT

  2. DIAGNOSIS


    1. If a malfunction occurs in the cruise control system during cruise control operation, the ECM automatically cancels the cruise control, illuminates the master warning light, sounds a buzzer and displays "CHECK CRUISE CONTROL SYSTEM" on the multi-information display to inform the driver of the malfunction. At this time, the ECM memorizes the malfunction in the form of 5-digit Diagnostic Trouble Codes (DTCs).

    2. The 5-digit DTCs can be read by connecting the intelligent tester to the DLC3.

    3. For details, refer to the Repair Manual.