Honda 2010 Ridgeline Owner's Manual page 218

Compass
The compass mirror has a light
sensor behind the right side of the
rearview mirror. Make sure the
extended sun visor or an accessory is
not covering the sensor.
214
Compass Calibration
The compass may need to be
manually calibrated after exposure to
a strong magnetic field. If the
compass seems to continually show
the wrong direction, do this.
Do this procedure in an open
NOTE:
area, away from buildings, power
lines, and other vehicles.
1. With the blue center icon
displayed, press and hold the
compass button for about 6
seconds. When the center icon
turns red, release the button.
2010 Ridgeline
2. Drive the vehicle slowly in circles
at less than 5 mph (8 km/h) until
the center icon turns blue. This
icon also turns blue by continuing
to drive the vehicle under normal
driving conditions. When you see
an actual heading on the compass,
calibration is completed.