Lincoln 2011 MKZ Hybrid Owner's Manual page 244

Driving
The following table lists possible causes and actions for this message
being displayed:
The surface of the left or right
radar is dirty or obstructed in
some way
The surface of the left or right
radar is not dirty or obstructed
Heavy rainfall or heavy snowfall is
interfering with the radar signals
Due to the nature of radar technology, it is possible to get a blockage
warning and not be blocked. This is rare and known as a false blockage
warning. A false blocked condition will either self clear or clear after a
key cycle.
Day and night brightness
The BLIS -CTA alert will automatically dim when the headlamp switch is
in the parking, on, or autolamp position, and night time darkness has
been detected by the sun sensor.
DRIVING THROUGH WATER
If driving through deep or standing
water is unavoidable, proceed very
slowly especially when the depth is
not known. Never drive through
water that is higher than the bottom
of the wheel rims (for cars) or the
bottom of the hubs (for trucks).
244
2011 MKZ Hybrid (hkz)
Owners Guide, 1st Printing
USA (fus)
Clean the fascia area in front of
the radar, either left or right side,
or remove obstruction.
Drive normally in traffic for a few
minutes to allow the radar to
detect that it is no longer blocked.
Note: the vehicle must be in D
(Drive) and a few vehicles must
pass so that the BLIS can clear a
blocked state.
No action required by the driver.
The system will automatically go
unblocked once the
rainfall/snowfall rate decreases or
stops. Do not use BLIS -CTA in
heavy rainfall or heavy snowfall.