GM Service Manual Online
For 1990-2009 cars only

The vehicle may have a manual rearview mirror with an eight-point compass display located in the upper right.

Mirror Operation

While sitting in a comfortable position, adjust the rearview mirror so you can see clearly behind your vehicle. Grip it in the center and move it up or down and side to side. The day/night control, located at the bottom of the mirror, adjusts the mirror to reduce headlamp glare from behind during evening or dark conditions. Push the control for daytime use; pull it for night use.

Compass Display

(On/Off): Press this button to turn the compass on or off. The compass display, can show a maximum of two characters. For example, NE is displayed for north-east.

When the ignition and the compass/temperature feature are on, character boxes will appear for about two seconds. After two seconds, the mirror will display the direction the vehicle is facing.

Compass Calibration

When on, the compass automatically calibrates as the vehicle is driven. If, after two seconds, the display does not show a compass direction, (N for North, for example), there may be a strong magnetic field interfering with the compass. Such interference may be caused by a magnetic antenna mount, magnetic note pad holder, or a similar magnetic item. If the letter C should ever appear in the compass window, the compass may need calibration.

Press and hold the on/off button for nine seconds to activate the compass calibration mode. CAL will be displayed in the compass window on the mirror.

The mirror can be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display shows a direction.

Compass Variance

Compass variance is the difference between earth's magnetic north and true geographic north. The mirror is set to zone eight upon leaving the factory. It will be necessary to adjust the compass to compensate for compass variance if you live outside zone eight. Under certain conditions, such as during a long-distance, cross-country trip, it will be necessary to adjust for compass variance. If not adjusted to account for compass variance, the compass could give false readings. To adjust for compass variance do the following:

  1. Find the current location and variance zone number on the following zone map.

  2. Object Number: 806305  Size: B4
  3. Press and hold the on/off button until a zone number appears in the display.
  4. Once a zone number appears in the display, press the on/off button quickly until the correct zone number appears in the display. If C appears in the compass window, the compass may need calibration. See "Compass Calibration" explained previously.