Jeep 2015 Grand Cherokee - Owner Manual - Manual (Page 210)

Turns And Bends
When driving on a curve with ACC engaged, the system
may decrease the vehicle speed and acceleration for
stability reasons, with no target vehicle detected. Once
the vehicle is out of the curve the system will resume
your original Set Speed. This is a part of normal ACC
system functionality.
NOTE:
On tight turns ACC performance may be limited.
Offset Driving Condition Example
Turn Or Bend Example
208 UNDERSTANDING THE FEATURES OF YOUR VEHICLE