Lincoln 2016 MKZ HYBRID Owner's Manual page 240

The radar sensor cover in the grille is dirty or obstructed
The surface of the radar sensor cover is clean but the message
remains in the display
Heavy rain, spray, snow or fog in the air interferes with the radar
Swirling water, snow or ice on the road surface interferes with the
radar signals
System Limitations
WARNING
The Pre-Collision Assist system's brake
support only reduces collision speed
if you first apply your brakes. You must brake
as you would in any typical braking situation.
Due to the nature of radar technology, there
may be certain instances where vehicles do
not provide a collision warning. These
include:
MKZ Hybrid (CC9) Hybrid Electric Vehicle (HEV), Canada/United States of America, enUSA, First Printing
Driving Aids
Cause
signals
• Stationary vehicles or vehicles moving
below 6.2 mph (10 km/h).
• Pedestrians or objects in the roadway.
• Oncoming vehicles in the same lane.
• Severe weather conditions (see blocked
sensor section).
• Debris build-up on the grille near the
headlamps (see blocked sensor section).
• Small distance to vehicle ahead.
• Large steering wheel and pedal
movements (very active driving style).
Clean the radar sensor cover or remove the obstruction
Wait a short time. The radar may take several minutes to reset after
you remove the obstruction
The Pre-Collision Assist system is temporarily disabled. Shortly after
weather conditions improve, the collision warning system automatically
The Pre-Collision Assist system is temporarily disabled. Shortly after
weather conditions improve, the collision warning system automatically
Damage to the front end of your vehicle may
alter the radar sensor's coverage area. This
may result in missed or false collision
warnings. Have an authorized dealer check
your radar sensor for proper coverage and
operation.
237
Action
reactivates
reactivates