2011 Chevrolet Silverado 1500 Regular Cab Owner's Manual - Page 150

5-6 Instruments and Controls 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. 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 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. 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