2013 Toyota Matrix Owners Manual - Page 290
2013 Toyota Matrix Manual
Page 290 highlights
3-7. Other interior features Calibrating the compass The direction display deviates from the true direction determined by the earth's magnetic field. The amount of deviation varies according to the geographic position of the vehicle. If you cross over a map boundary shown in the illustration, the compass will deviate. To obtain higher precision or perfect calibration, refer to the following.