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 

   If the actual vehicle speed rises above the set vehicle speed, a signal is sent to the HV control motor in order to close the throttle valve. Conversely, if the vehicle speed falls below the set vehicle speed, a signal is sent to the HV control motor in order to open the throttle valve and increase the driving force.

2. Setting 

   If the - SET SW is pressed while the ON-OFF SW 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 SW is held down while driving with the cruise control active, the coast control sets the cruise control request opening to 'Zero' (Note: the throttle valve can not be completely closed due to idle speed control, 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 SW 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 >

   If the + RES SW is held down while driving with the cruise control active, the acceleration control operates the electric throttle motor to open the throttle valve to gradually and continuously accelerate vehicle. 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 up >

   If the - SET SW 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 25 mph (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.

   < Set vehicle speed when vehicle decreases to below low speed limit >

   The set vehicle speed is retained in the memory even if the vehicle speed decreases to below the low speed limit.

6. High Speed Limit 

   This is the highest speed to which the cruise control can be set and is approximately 125 mph (200 km/h). Cruise control cannot be set if the vehicle speed exceeds the high speed limit. The vehicle cannot be accelerated above the high speed limit using the + RES SW.

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 lamp switch comes ON
   2. CANCEL switch comes ON in the control switch
   3. ON-OFF switch goes OFF
   4. D position circuit changes from ON to OFF in the park/neutral position switch (Shift position is changed from D, 5 or 4 to N, 3, 2 or 1)

   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 SW is pressed.

   < Set vehicle speed when vehicle decreases to below low speed limit >

   Since the set vehicle speed is retained in the memory even if the vehicle speed decreases to below the low speed limit, when the vehicle speed increases to above the low speed limit, the resume control operation is permitted.

8. Shift-Down Control 

   If driving up a hill with the cruise control active, the gear may be shifted down by the A/T control. When the hill is judged to have finished (based on the throttle opening information) the gear will be shifted back up after a set time. If the gear was shifted down during acceleration or resume control, the gear will be shifted back up after the acceleration or resume control ends.

9. Auto Cancel 
   1. The set vehicle speed will be erased from memory and the cruise control will be canceled under the conditions outlined below. In addition, the cruise operation indicator will blink until the ON-OFF switch has been turned OFF. Finally, the cruise control will remain inoperable until the switch is turned ON again.
      1. The stop light switch circuit is open or shorted
      2. The vehicle speed signal is abnormal
      3. Any electronic throttle parts are abnormal
   2. The set vehicle speed will be erased from memory and the cruise control will be canceled under the conditions outlined below. In addition, the cruise operation indicator will blink until the ON-OFF switch has been turned OFF. Finally, the cruise control will remain inoperable until the power switch is turned OFF.
      1. The stop light switch input circuit is abnormal
      2. The cancel circuit is abnormal
   3. Under the following condition, the set vehicle speed will be erased from memory and the cruise control will be canceled because there is a possibility that the vehicle is overloaded or the set vehicle speed is too high (Cruise control can be resumed):

      The vehicle speed falls to 10 mph (16 km/h) or more below the set vehicle speed. (Set vehicle speed deletion)

   4. If the following condition occurs, the cruise control will be canceled.

      The vehicle speed falls below the low speed limit.

   < Set vehicle speed when vehicle decreases to below low speed limit >

   The set vehicle speed will be retained in memory even if the vehicle speed falls below the low speed limit. (Resetting and resume control are possible)