2005 Toyota 4Runner Owners Manual - Page 675

'05 4Runner_U (L/O 0504) CALIBRATING THE COMPASS (deviation calibration) The direction display on the compass deviates from the true direction determined 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 "COMP" switch until the zone number appears on the display. Then push the "COMP" switch, referring to the following map to select the number of the zone where the vehicle is. 251