If the letter C should ever appear in the compass, the compass is in calibration mode and needs calibrated. The compass can be calibrated by driving the vehicle in complete circles at 5 mph (8 km/h) or less until the display reads a direction.

The compass can be manually calibrated by depressing and holding the COMPASS button (or the ON/OFF button if equipped with OnStar® controls) until the letter C is displayed. Then drive the vehicle in complete circles at 5 mph (8 km/h) or less until the display reads a direction. If the direction on the compass is incorrect, inspect for the correct compass variance. Refer to Compass Variance Setup Description .