GM Service Manual Online
For 1990-2009 cars only

Compass Calibration and Magnetic Variance Driver Information Center (DIC)

Under certain circumstances the compass may have to be calibrated especially if the vehicle is driven over a long distance trip. Reset the zone through the DIC if the compass zone is not set correctly. If the compass heading is blank or the driver information center (DIC) shows CAL or C, the compass must be re-calibrated.

Compass variance is the difference between the earth's magnetic north and the true geographic north. If the compass is not set in the zone where you live, the compass may give false readings. The compass must be set to the variance zone in which the vehicle is travelling.

Compass Variance (Zone) Procedure

  1. Do not set the compass zone when the vehicle is moving. Only set when the vehicle is in PARK (P).
  2. Press and hold the reset stem in the IPC until the currently set variance zone number (0-30) and direction (E or W) appears in the DIC. Refer to the owners manual for your variance zone map to determine the correct zone.

    World Magnetic Variation Map


    Object Number: 384280  Size: MF

    Object Number: 9020  Size: SH
  3. Locate your geographic location. Refer to the variation zone map.
  4. Find the vehicle's current location and variance zone number/direction on the map.
  5. To select the appropriate variance zone, turn the reset stem clockwise or counterclockwise and then release to advance to the next available zone. Repeat as needed.
  6. If the zone does not change while turning the reset stem, try turning it in the opposite direction.

  7. Once the appropriate variance zone is selected, press the reset stem. A flashing C will display.
  8. Calibrate the compass. See "Compass Calibration Procedure" following.

You cannot reset the Compass mode. This mode is retained during ignition OFF.

Compass Calibration

The compass can be manually calibrated. Only calibrate the compass in a magnetically clean and safe location, such as an open parking lot, where driving the vehicle in circles is not a danger. It is suggested to calibrate away from tall buildings, utility wires, manhole covers, or other industrial structures, if possible.

If C or CAL should ever appear in the DIC display, the compass should be calibrated.

If the DIC display does not show a heading, for example, N for North, or the heading does not change after making turns, there may be a strong magnetic field interfering with the compass. Such interference may be caused by a magnetic CB or cell phone antenna mount, a magnetic emergency light, magnetic note pad holder, or any other magnetic item. Turn off the vehicle, move the magnetic item, then turn on the vehicle and calibrate the compass.

To calibrate the compass, use the following procedure:

Compass Calibration Procedure

  1. Before calibrating the compass, make sure the compass is set to the variance zone in which the vehicle is located. See "Compass Variance (Zone) Procedure".
  2. Do not operate any switches such as window, sunroof, climate controls, seats, etc. during the calibration procedure.

  3. Press the reset stem until the C or CAL starts flashing.
  4. Drive the vehicle in tight circles at less than 5 mph (8 km/h) to complete the calibration.
  5. When the calibration is complete, the vehicle heading, for example, N for North, displays instead of the C or CAL.