2004 Jeep Grand Cherokee Owner's Manual - Page 105

UNDERSTANDING THE FEATURES OF YOUR VEHICLE 105 NOTE: To ensure proper compass calibration, make sure the compass variance is properly set before manually calibrating the compass. Refer to Variance Map. To Put Into a Calibration Mode Turn on the ignition and set the display to "Compass/ Temperature." Press and hold the RESET button to change the display between VAR (compass variance) and CAL (compass calibration) modes. When the CAL symbol is displayed complete three 360 degree turns in an area free from large metal objects or power lines. The CAL symbol will turn off and the compass will function normally. 3 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 according to the Compass Variance Map.