RAM 2013 Cargo VAN Owner's Manual page 141

BSM Warning Light
The BSM system monitors the detection zone from three
different entry points (side, rear, front) while driving to
see if an alert is necessary. The BSM system will issue an
alert during these types of zone entries.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 139
Entering From The Side
Vehicles that move into your adjacent lanes from either
side of the vehicle.
Side Monitoring
3