Dodge 2010 Ram Truck Chassis Owner's Manual page 148

146 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
Compass Variance
Compass Variance is the difference between magnetic
North and Geographic North. In some areas of the
country, the difference between magnetic and geographic
North is great enough to cause the compass to give false
readings. If this occurs, the compass variance must be set
using the following procedure:
NOTE: Magnetic materials should be kept away from
the overhead console. This is where the compass sensor is
located.
Compass Variance Map
1. Turn the ignition switch to the ON/RUN position.
2. Press the MENU button until "Personal Settings" is
displayed.
3. Press the STEP button until "Compass Variance" is
displayed.