Electronic Compass Calibration: Variance

Variance is defined as the difference between magnetic north and geographic north. In some areas of the country, this difference is great enough to cause false compass readings. Set the variance for a particular location as follows:

1. Determine the vehicle's location on the zone map.

   Note the zone number.

Fig 1: Zone Variance Map
Courtesy of GENERAL MOTORS CORP.
2. Turn ON the ignition.
3. Press the MODE button until the compass/temperature mode appears.
4. Press and hold the RESET button on the overhead console for approximately 5 seconds. The last entered variance zone appears on the display.
5. Press the MODE button until the correct zone number appears on the display.
6. Press the RESET button in order to set the new variance zone and resume normal operation.

   The display will illuminate all segments briefly in order to acknowledge the change in the zone number.