Lincoln 2013 MKZ Owner's Manual page 218

Note: It is possible to get a blockage
warning with no blockage present; this
is rare and known as a false blockage
warning. A false blocked condition
either self-corrects or clears after a key
cycle.
E142443
The system uses radar sensors which
are located behind the bumper fascia
on each side of your vehicle. Do not
allow these areas to become
obstructed by mud, snow or bumper
stickers, as this can cause degraded
system performance.
If the system detects a degraded
performance condition, a message
warning of a blocked sensor or a
message warning of low visibility will
appear in the information display and
the alert indicator illuminates in the
appropriate mirror(s). The information
display warning can be cleared but
the alert indicator remains
illuminated.
When the blockage is removed, the
system can be reset in two ways:
• when at least two objects are
detected while driving, or
• turn the ignition from on to off,
then back on.
Driving Aids
If the blockage is still present after the
key cycle, the system senses again
that it is blocked after driving in traffic.
Reasons for messages being
The radar
surface is
dirty or
obstructed
The radar
surface is
not dirty
or
obstructed
Heavy
rainfall/
snowfall
interferes
with the
radar
signals
System Limitations
The BLIS and cross traffic alert
systems do have their limitations;
situations such as severe weather
conditions or debris build-up on the
sensor area may limit vehicle
detection.
215
displayed
Clean the fascia area in
front of the radar or
remove the obstruction.
Drive normally in traffic
for a few minutes to
allow the radar to detect
passing vehicles so it can
clear the blocked state.
No action required. The
system automatically
resets to an unblocked
state once the rainfall or
snowfall rate decreases
or stops. Do not use BLIS
or cross traffic alert in
these conditions.