With some minor differences, operating the available Dynamic Radar Cruise Control system is very similar to conventional cruise control. However, when the system detects slower traffic ahead, it will slow the Sienna automatically to match their speed and maintain a preset distance.
You can change that distance using a button on the steering wheel. When activated, the system defaults to the long setting. A display in the instrument cluster indicates which distance has been selected. Pressing the button repeatedly allows you to cycle through the three distances available.
The driver can disable the distance holding feature by pressing and holding the cruise control stalk forward for at least two seconds. The Ready Indicator and distance graphic will disappear in the instrument cluster.
Auto cancel below 25 mph
The vehicle-to-vehicle distance control feature will be automatically canceled when the vehicle falls below 25 miles per hour, Vehicle Stability Control, or VSC, is activated, the sensor is covered or blocked, the brake is applied, or the windshield wipers are running continuously.