1998 Pontiac Bonneville Owner's Manual - Page 139

Sometimes, strong magnetic fields can affect the compass. If the CALIBRATE light comes on as shown above, try calibrating the compassas follows: 1. Drive the car toan open, flat area. If you put large metal objects golf clubsin the trunk like they could affect accuracy. the accuracy is close, the If these objects over time. compass will adapt to If you use an antenna with a magnetic base, best it is to mount it away from the centerof the trunk near the rear window. The rear defog system can affect accuracy, and the compass correctsfor the rear defog. However, the rear if sharp turns, the defog is turned on while making accuracy may be When you turn the rear defog off off. again, the accuracy returns normal. to D o not turn on the rear defog if you are trying to calibrate. The system will not allow calibration. You the will hearthe chime, and CALIBRATE will flash for a few seconds. 2. Press and hold the MODE button until the CALIBRATE light reappears. 3. Release the MODE button. The heading display will start to rotate. 4. Drive the car in small circles. Don'tdrive faster than 10 mph (16 km/h). 5. Drive in circles until the CALIBRATE light goes out. It usually takes to five circles. one 6. Your compass should be calibrated. will know You this when the direction bars are and the on CALIBRATE light is off. Compass Accuracy Your compass may show different headings around bridges, power lines, large metal objects and steep hills. This is noma1 and is true of compasses in general. Be aware thatm t l objects are sometimes buried the ea in ground. Theycan affect accuracy and you may not know they are there.As an example, many concrete roads have metal reinforcements inside. 2-82