Low speed automatic cancellation

ACC is not functional at vehicle speeds below 16 mph (26 km/h). Once the vehicle speed drops below 16 mph (26 km/h), an audible alarm will sound and the automatic braking will be released.
See also:
Transmission fluid
Checking 6–speed automatic transmission fluid
Refer to your scheduled maintenance information for scheduled
intervals for fluid checks and changes. Your transmission does not
consume fluid. Howev ...
Reaking-in your vehicle
Your vehicle does not need an extensive break-in. Try not to drive
continuously at the same speed for the first 1,000 miles (1,600 km) of
new vehicle operation. Vary your speed frequently in order ...
Continuously controlled damping
Throughout 13 decades of the automobile's development, suspension engineers
have worked tirelessly to find an ideal balance between smooth ride and
satisfying, confident handling. Traditionally, smo ...
