Jeep Wrangler Owner's Manual page 163

162 SAFETY
Overtaking Traffic
If you pass another vehicle slowly with a relative speed
less than 15 mph (24 km/h) and the vehicle remains in
the blind spot for approximately 1.5 seconds, the warning
light will be illuminated. If the difference in speed between
the two vehicles is greater than 15 mph (24 km/h), the
warning light will not illuminate.
Overtaking/Approaching
Overtaking/Passing
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.
The BSM system will not alert you of objects that are
traveling in the opposite direction of the vehicle in
adjacent lanes.
Opposing Traffic