Toyota Corolla 2007 Operating Manual page 171

The compass sensor is on the inside
rear view mirror.
NOTICE
Do not put magnets or a metal object
on or near the inside rear view mirror
of the vehicle. Doing this may cause
malfunction of the compass sensor.
'07 Corolla_U (L/O 0608)
CALIBRATING THE COMPASS (deviation
calibration)
The direction display on the compass
deviates from the true direction deter-
mined by the earth's magnetic field. The
angle of deviation varies according to the
geographic position of the vehicle.
To adjust this deviation, stop the vehicle,
then push and hold the both personal light
switches until the zone number appears
on the display. Then push the right side
or left side personal light switch, referring
to the following map to select the number
of the zone where the vehicle is.
2007MY COROLLA from Oct. '06 Prod. (OM12B32U)
163