When there is no vehicle ahead, ACC maintains the set speed.

When there is a vehicle ahead, the ACC maintains a set distance within the set speed.

If the vehicle ahead pulls over out of the way, the ACC accelerates the vehicle to the set speed and maintains that speed.

The ACC measures the distance from the vehicle ahead using the millimeter wave radar, and it determines if the target vehicle driving ahead is in the same lane by using inputs from the output shaft (countershaft) speed sensor and the yaw rate-lateral acceleration sensor.

If the ACC detects a slow vehicle and the distance to the vehicle ahead is closing, the vehicle speed is reduced primarily by closing the throttle, and additional slowing is accomplished by using the brakes. If the vehicle ahead is too close, an alarm sounds.

If a slower vehicle ahead accelerates, the throttle is opened to accelerate the vehicle (up to the set speed.) to maintain the following distance.