Stationary Objects And Vehicles
ACC does not react to stationary objects and stationary vehicles. For example, ACC will not react in situations where the vehicle you are following exits your lane and the vehicle ahead is stopped in your lane. Always be attentive and ready to apply the brakes if necessary.

See also:
Activating Adaptive Cruise Control (ACC)
You can only activate ACC if the vehicle speed is above
20 mph (32 km/h).
When the system is turned on and in the READY state,
the Electronic Vehicle Information Center (EVIC) displays
“Adapt ...
Power-Up
After switching the ignition key from OFF to either the
ON or ACC position, or after a language change, you
must wait at least fifteen seconds prior to using the
system.
...
System Activation
Sirius Satellite Radio service is pre-activated, and you
may begin listening immediately to the one year of audio
service that is included with the factory-installed satellite
radio system in yo ...


