System Outline

The cruise control system is a constant vehicle speed controller with which it is possible to automatically adjust the opening of the engine throttle valve without depressing the accelerator pedal, but by operating a switch instead.

1. Constant Speed Control 

   When the actual vehicle speed is faster than the set vehicle speed, a signal is sent to the electric throttle motor to rotate it in order to close the throttle valve. Alternatively, when the vehicle speed is slower than the set vehicle speed, a signal is sent to the electric throttle motor to rotate in order to open the throttle valve.

2. Setting 

   If the - SET switch is pressed while the ON-OFF switch is ON (and the vehicle speed is within the settable range: Above the low speed limit and below the high speed limit), then the vehicle speed at the point at which the switch is released will be stored in memory and the vehicle will be controlled to drive constantly at that speed.

3. Coast, Tap Down 

   <Coast>

   If the - SET switch is held down while driving with the cruise control active, the coast control sets the cruise control request throttle closing (Note: the throttle valve can not be completely closed due to ISC, etc.) to gradually and continuously decelerate the vehicle as long as the switch is held down. It then stores in memory the vehicle speed at which the switch is released and controls the vehicle to drive constantly at that speed.

   <Tap down>

   If the - SET switch is pressed momentarily (Approx. 0.5 sec.), the set vehicle speed is reduced in steps of approximately 1.6 km/h every time the switch is pressed. If the tap down operation attempts to put difference of more than 5 km/h between the set vehicle speed and the actual vehicle speed, then the vehicle speed at which the switch is released will be stored in the memory and the vehicle will be controlled to drive constantly at that speed.

4. Acceleration, Tap Up 

   <Acceleration>

   When the + RES switch is held down while driving with the cruise control active, the acceleration control rotates the electric throttle motor to open the throttle valve to gradually and constantly accelerate the vehicle, and stores the current vehicle speed in the memory when the switch is released and controls the vehicle to drive constantly at that speed.

   <Tap up>

   If the + RES switch is pressed momentarily (Approx. 0.5 sec.), the set vehicle speed is increased in steps of approximately 1.6 km/h every time the switch is pressed. If the difference between the set vehicle speed and actual vehicle speed becomes more than 5 km/h, the tap up operation will not change the set vehicle speed further.

5. Low Speed Limit 

   This is the lowest speed to which the cruise control can be set and is approximately 40 km/h. The cruise control cannot be set if the vehicle speed is below than the low speed limit. If the vehicle speed drops below the low speed limit while driving with the cruise control active, the cruise control will be automatically cancelled and the set vehicle speed will be erased from the memory.

6. High Speed Limit 

   This is the highest speed to which the cruise control can be set and is approximately 200 km/h. The cruise control cannot be set if the vehicle speed is higher than the high speed limit. Further, the vehicle cannot be accelerated above the high speed limit using the + RES switch.

7. Cancel 

   If any of the following signals are received while driving with the cruise control active, the cruise control will be cancelled.

   1. Stop light switch comes ON
   2. CANCEL switch comes ON in the control switch
   3. ON-OFF switch goes OFF
   4. D position circuit changes from D to M
   5. When the shift position is D and the transmission gear lower than 3rd gear is selected with the paddle shift controls
8. Resume 

   As long as the vehicle speed stays above the low speed limit after the cruise control has been canceled due to one of the above signals, the cruise control will resume operation and return to the speed that was set at the time the cruise control was canceled if the + RES switch is pressed.

9. Shift-Down Control 

   When the vehicle climbs a hill while driving with the cruise control active, the gear may be shifted down by the A/T control. When the hill climbing has been determined to have finished, based on the throttle opening information, the gear will be shifted up again after a set time. If the gear is shifted down during acceleration or resume control, the gear is shifted back up after the acceleration or resume control ends.

10. Auto Cancel 
    1. The set vehicle speed will be erased from memory and the cruise control will be cancelled under the conditions outlined below. Until the ON-OFF switch is turned ON again, the cruise operation indicator will blink and the cruise control cannot be activated.
       1. If the stop light switch is disconnected or short-circuits.
       2. If the vehicle speed signal is abnormal.
       3. If the electronic throttle parts are abnormal.
    2. The set vehicle speed will be erased from memory and the cruise control will be cancelled under the conditions outlined below. The cruise operation indicator will blink and the cruise control cannot be activated unless the engine switch is turned off.
       1. If the stop light switch input circuit is abnormal.
       2. If the cancel circuit is abnormal.
    3. The set vehicle speed will be erased from memory and the cruise control will be cancelled under the following condition.
       1. If the vehicle speed falls to less than the set vehicle speed minus 16 km/h).
    4. The cruise control will be cancelled under the following condition.
    1. If the vehicle speed falls below the low speed limit (about 40 km/h).