GM Service Manual Online
For 1990-2009 cars only

Compass Calibration

Before calibrating the compass, drive the vehicle to an area that is magnetically clean or free of large metallic objects. Verify there are no magnetized objects on the inside or outside of the vehicle close to the mirror.

  1. Start the engine.
  2. Press and hold both map light switches or the on/off switch (w/UE1) until the letter "C" is displayed.
  3. Drive the vehicle in circles at a speed of less than 8 km/h (5 mph) until the "C" is replaced by a proper vehicle heading. The calibration procedure is now complete.

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.

    World Magnetic Variation Map


    Object Number: 384280  Size: MF
  1. Locate your current geographic location on the World Magnetic Variation Map.
  2. Turn ON the ignition, with the engine OFF.
  3. Press and hold both map light switches or the on/off switch (w/UE1) until a zone number appears on the compass display.
  4. Depress either map lamp switches or the on/off switch (w/UE1) to select the desired zone number.
  5. Wait 5 seconds, the display will return to a compass heading. The variance procedure is now complete.