See also:

Compass Calibration Procedure
1. Before calibrating the compass, check that the compass zone is set to the variance zone in which the vehicle is located. See “Compass Variance (Zone) Procedure” earlier in this section. ...

Footnotes — Maintenance Schedule Additional Required Services — Normal
a) Or every two years, whichever comes first. More frequent replacement may be needed if the vehicle is driven in areas with heavy traffic, areas with poor air quality, or areas with high du ...

When to Check
Check your tires once a month or more. Also, check the tire pressure of the spare tire. ...