GM Service Manual Online
For 1990-2009 cars only

Compass Magnetic Variation Adjustment

Magnetic variation adjustments are required when the compass displays a constant error in heading. Variation is the difference between magnetic north and true north due to geographical location.


    Object Number: 9020  Size: SH
  1. Turn ON the ignition, with the engine OFF.
  2. Press the option button until - PRESS SET/RESET TO CHANGE COMPASS ZONE - is displayed on the DIC.
  3. Locate your vehicle's current location and variance zone number on the map . Zones 1 through 15 are available.
  4. Scroll through and select the appropriate variance zone using the set/reset botton. To view the direction the vehicle is moving, navigate to one of the trip/fuel menu screens using the DIC fuel infromation button and the direction will be shown at the right top corner of the DIC display.

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

Compass Calibration

Before calibrating the compass, drive the vehicle to an area that is magnetically clean (free of large metallic objects). Only calibrate the compass in a safe location where driving the vehicle in circles is not a problem.

  1. With the ignition ON, press the option button until - PRESS SET/RESET TO CALIBRATE COMPASS - is displayed in the DIC
  2. Press the set/reset button in order to start compass calibration.
  3. The DIC should display - CALIBRATING BEGUN DRIVE IN CIRCLES.
  4. Drive the vehicle in circles at a speed of less than mph 8 km/h (5 mph) until calibration is complete. The DIC will display - CALIBRATION COMPLETE - when the calibration is complete.