FORD 2013 Explorer v.1 - Manual (Page 260)

Blocked Sensor
WARNING: Do not use ACC when towing a trailer with brake
controls. Aftermarket trailer brakes will not function properly
when ACC is activated because the brakes are electronically controlled.
Failing to do so may result in loss of vehicle control, which could result
in serious injury.
WARNING: Do not use tires sizes other than those
recommended because this can affect the normal operation of
ACC. Failing to do so may result in a loss of vehicle control, which
could result in serious injury.
A message regarding a blocked
sensor is displayed if the radar
signals from the sensor have been
obstructed. The sensor is located
behind a fascia cover near the driver
side of the lower grille. A vehicle
ahead cannot be detected and the
system will not function when the
radar signals are obstructed. The
following table lists possible causes
and actions for this message being
displayed.
Cause Action
The surface of the radar in the
grille is dirty or obstructed in
some way Clean the grille surface in front of
the radar or remove the object
causing the obstruction
The surface of the radar in the
grille is clean but the message
remains in the display Wait a short time. It may take
several minutes for the radar to
detect that it is no longer
obstructed
Heavy rain or snow is interfering
with the radar signals Do not use ACC in these condition
because it may not detect, warn,
or respond to potential collisions.
260 Cruise Control
2013 Explorer (exp)
Owners Guide gf, 1st Printing
USA (fus)