2013 Chevrolet Express 1500 Cargo Owner Manual - Page 107

Instruments and Controls 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 T until PRESS V TO 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 V to scroll through and select the appropriate variance zone. 4. Press 3 until the vehicle heading, for example, N for North, is displayed in the DIC. 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. 5-5 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.