Jeep Grand Cherokee 2013 Owner's Manual page 138

136 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
Overtaking/Passing Stationary Objects
The BSM system is designed not to issue an alert on
stationary objects such as guardrails, posts, walls, foliage,
berms, etc. However, occasionally the system may alert
on such objects. This is normal operation and your
vehicle does not require service.