Toyota Lexusc Owner's Handbook Manual page 287

STEERING WHEEL AND MIRRORS
Leaving the system after the calibration for several seconds,
the direction will appear on the display. It shows the zone
number is set.
CAUTION
Do not adjust the display while the vehicle is moving.
Be sure to adjust the display only when the vehicle is
stopped.
268
Calibrating the compass (circling calibration)
To rectify the compass, stop the vehicle and push and hold the
"COMP" switch until "C" appears on the display.
There is also a case that "C" appears on the display in case of
a drastic change in the magnetic field.