GMC Sierra Owners Manual
The vehicle may have a compass in the Driver Information Center (DIC).
The zone is set to zone eight upon leaving the factory. Your dealer will set the correct zone for your location.
Under certain circumstances, such as during a long-distance, cross-country trip or moving to a new state or province, it will be necessary to compensate for compass variance by resetting the zone through the DIC if the zone is not set correctly.
Compass variance is the difference between the earth's magnetic north and true geographic north. If the compass is not set to 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 traveling.
To adjust for compass variance, use the following procedure:
Compass Variance (Zone) Procedure
1. Do not set the compass zone when the vehicle is moving. Only set it when the vehicle is in P (Park).
Press the vehicle information button until PRESS TO CHANGE COMPASS ZONE displays. Or, if the vehicle does not have DIC buttons, press the trip odometer reset stem until CHANGE COMPASS ZONE displays.
2. Find the vehicle's current location and variance zone number on the map.
Zones 1 through 15 are available.
3. Press the set/reset button to scroll through and select the appropriate variance zone.
4. Press the trip/fuel button until the vehicle heading, for example, N for North, is displayed in the DIC. Or, if the vehicle does not have DIC buttons, press and hold the trip odometer reset stem for two seconds to select the next available variance zone. Repeat this step until the appropriate variance zone is displayed.
5. If calibration is necessary, calibrate the compass. See “Compass Calibration Procedure” following.
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 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 zone is set to the variance zone in which the vehicle is located. See “Compass Variance (Zone) Procedure” earlier in this section.
Do not operate any switches such as window, sunroof, climate controls, or seats during the calibration procedure.
2. Press the vehicle information button until PRESS TO CALIBRATE COMPASS displays. Or, if the vehicle does not have DIC buttons, press the trip odometer reset stem until CALIBRATE COMPASS displays.
3. Press the set/reset button to start the compass calibration. Or, if the vehicle does not have DIC buttons, press and hold the trip odometer reset stem for two seconds to start the compass calibration.
4. The DIC will display CALIBRATING: DRIVE IN CIRCLES. Drive the vehicle in tight circles at less than 8 km/h (5 mph) to complete the calibration. The DIC will display CALIBRATION COMPLETE for a few seconds when the calibration is complete. The DIC display will then return to the previous menu.