2008 Chevrolet Uplander Owner's Manual - Page 217

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, seats, etc. during the calibration procedure. 2. Press the menu button until COMPASS CALIBRATION displays. 3. Press the set/reset button to start the compass calibration. 4. The DIC will display CALIBRATION BEGUN DRIVE UNTIL DONE. Drive the vehicle in tight circles at less than 5 mph (8 km/h) to complete the calibration. The DIC will display CALIBRATION FINISHED for a few seconds when the calibration is complete. 3-57