Cruise Control
System OutlineThe cruise control system is a constant vehicle speed controller that allows the opening of the engine throttle valve to be automatically adjusted through hand switch operations without depressing the accelerator pedal when a driver wishes to drive at a constant speed on a highway.
1. Constant Speed Control
When the actual vehicle speed is higher than the set vehicle speed, a signal is sent to operate the electric throttle motor in order to close the throttle valve. Conversely, when the vehicle speed is lower than the set vehicle speed, a signal is sent to operate the electric throttle motor in order to open the throttle valve.
2. Setting
When the - SET SW is operated with the ON-OFF SW ON (Within the set table vehicle speed range; above the low speed limit and below the high speed limit), the vehicle speed at which the SW is turned OFF is stored in the memory and the vehicle is controlled to maintain that speed.
3. Coast, Tap Down
When the - SET SW is held ON during cruise control driving, the coast control makes the cruise control request opening 'zero' (NOTE: the throttle valve is not completely closed due to idle speed control, etc) to reduce the vehicle speed, stores in the memory the vehicle speed at which the SW is turned OFF, and controls the vehicle to maintain that speed.
When the - SET SW is turned ON momentarily (For approximately 0.6 seconds), the set vehicle speed decreases in increments of approximately 1.6 km/h (1 mph) for each SW operation. When the difference between the set vehicle speed and the actual vehicle speed is more than 5 km/h (3 mph), the vehicle speed at which the SW is turned OFF is stored in the memory and the vehicle is controlled to maintain that speed.
4. Acceleration, Tap Up
When the + RES SW is held ON during cruise control driving, the acceleration control operates the electric throttle motor to open the throttle valve to accelerate the vehicle. The vehicle speed at which the SW is turned OFF is stored in the memory and the vehicle is controlled to maintain that speed.
When the + RES SW is turned ON momentarily (For approximately 0.6 seconds), the set vehicle speed increases in increments of approximately 1.6 km/h (1 mph) for each SW operation. When the difference between the set vehicle speed and the actual vehicle speed is more than5 km/h (3 mph), the tap up operation does not change the set vehicle speed.
5. Low Speed Limit
This refers to the lower limit of the set table speed range and is approximately 40 km/h (25 mph). Cruise control cannot be set if the vehicle speed is lower than the low speed limit. When the vehicle speed decreases to below the low speed limit during cruise control driving, the cruise control is automatically canceled.
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 refers to the upper limit of the set table speed range and is approximately 200 km/h (125 mph). Cruise control cannot be set if the vehicle speed exceeds the high speed limit. The vehicle cannot be accelerated to above the high speed limit using the + RES SW operation.
7. Cancel
When any of the following signals is input during cruise control driving, cruise control is canceled.
1. Stop lamp SW ON
2. CANCEL SW ON in the control SW
3. ON-OFF SW OFF
4. D position circuit ON to OFF in the park/neutral position SW (Shift position is changed from D, 6, 5 or 4 to N, 3, 2 or 1) When the vehicle speed stays above the low speed limit after cruise control is canceled by one of the above signals and the + RES SW is turned from OFF to ON, the cruise control resumes and the vehicle is gradually accelerated to the set vehicle speed that was used before cancellation.
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
When the vehicle climbs a hill while running under cruise control, the gear may be shifted down by the A/T control. When the hill climb is judged to have finished, based on the throttle opening information, the gear is shifted up 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.
9. Auto Cancel
1. The set vehicle speed is erased from the memory and the cruise control is canceled under the following conditions. In addition, the cruise operation indicator blinks until the ON-OFF SW is turned OFF and cruise control is prohibited until the SW is turned ON again.
a. The stop lamp SW circuit is open or short
b. The vehicle speed signal is abnormal
c. Any electronic throttle parts are abnormal
2. The set vehicle speed is erased from the memory and the cruise control is canceled under the following conditions. In addition, the cruise operation indicator blinks until the ON-OFF SW is turned OFF and cruise control remains prohibited unless the power SW is turned OFF.
a. The stop lamp SW input circuit is abnormal
b. The cancel circuit is abnormal
3. Under the following condition, the set vehicle speed is erased from the memory and the cruise control is 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 is 16 km/h (10 mph) more below the set vehicle speed. (Set vehicle speed deletion)
4. If the following condition occurs, the cruise control is canceled.
The vehicle speed decreases to below the low speed limit.
The set vehicle speed is retained in the memory even if the vehicle speed decreases to below the low speed limit. (Resetting and resume control are possible)