See also:

Setting the Tone(Bass/Midrange/Treble)
AUDIO: Push and release the AUDIO knob until BASS, MID (midrange) (without Bose®), or TREB (treble) displays. Turn the knob to increase or to decrease the tone. The display shows the bass, midran ...

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. I ...

Reporting Safety Defects to General Motors
In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors. Call 1-800-521-7300, or write: Buick Customer Assistance Center P.O. Box 33136 ...