Honda 2012 Pilot Owner's Manual page 496

Parking Sensor System
If the system develops a problem,
you will see a ''CHECK PARKING
SENSOR SYSTEM'' message on the
multi-information display.
488
If there is a problem with any of the
operational sensors, the indicators
for these sensors will appear
constantly in red.
Very often, a sensor covered with
mud, ice, snow, etc. is the cause of
this display. Check the sensors first.
If the indicators stay on or the
beeper does not stop, have the
system checked by your dealer.