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Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1551 (Instrument Panel System Displays & Gauges) >> Description and Operation >> Compass Calibration and Magnetic Variance (without OnStar Only) >> Compass Magnetic Variation Adjustment

Compass Magnetic Variation Adjustment

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Compass variance is the difference between the earth's magnetic north and true geographic north. If not adjusted to account for compass variance, the compass in the vehicle could give false readings. Under certain circumstances, such as during a long distance cross-country trip, it will be necessary to compensate for compass variance and reset the zone through the DIC.

Fig 1: World Magnetic Variation Map
GM384280Courtesy of GENERAL MOTORS CORP.
    Fig 2: Magnetic Variation Zones
    GM9020Courtesy of GENERAL MOTORS CORP.
  1. Locate your geographic location. Refer to the variation zone map.
  2. Turn ON the ignition with the engine OFF.
  3. Press the vehicle information button until PRESS TO CHANGE COMPASS ZONE displays on the DIC.
  4. Press the set/reset button to scroll through and select the appropriate variance zone.
  5. Navigate to one of the trip/fuel menu screens to view the direction the vehicle is moving. This will be shown in the top right corner of the DIC display.

If the compass needs to be calibrated, use the compass calibration procedure above.