Jeep grand cherokee 2018 Owner's Manual page 524

522 MULTIMEDIA
Setting Name Selectable Options
When the "Compass Variance" feature is selected, it allows the compass variance to be set to any number from 1 to
15 per the compass variance zone map figure.
Compass Variance is the difference between Magnetic North and Geographic North. To compensate for the differ-
ences, the variance should be set for the zone where the vehicle is being driven, illustrated in the zone map. Once
properly set, the compass will automatically compensate for the differences when calibrated, and provide the most
accurate compass headings.
Compass Variance Zone Map