Lexus GS430 User Manual page 240

STEERING WHEEL AND MIRRORS
G17016
"Zone number
If the direction is displayed several seconds after adjustment,
the calibration is finished.
216
CAUTION
Do not adjust the display while the vehicle is moving.
Be sure to adjust the display only when the vehicle is
stopped.
CALIBRATING THE COMPASS (circling calibration)
G17011
"CAL" appears on the display in case the circling calibration is
required due to a drastic change in the magnetic field. To
rectify this, follow the calibration procedure below.