2006 Jeep Grand Cherokee Owner's Manual - Page 200

200 UNDERSTANDING YOUR INSTRUMENT PANEL 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 Start the engine and leave the transmission in the P (Park) position. Set the display to "Compass/Temperature." Press and hold the C/T button for approximately 5 seconds to change the display to compass variance mode; holding the button for an additional 5 seconds will flash the "CAL" symbol indicating compass calibration mode. When the "CAL" indicator is flashing, complete one or more 360 degree turns, under 5 mph (8 km/h), in an area free from large metal objects or power lines. The "CAL" indicator will turn off and the compass will function normally. Compass/Temperature Button 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.