Compass Variance
Compass variance is the difference between earth’s magnetic north and true geographic north. The mirror is set to zone eight upon leaving the factory.
It will be necessary to adjust the compass to compensate for compass variance if you live outside zone eight. Under certain circumstances, such as during a long distance cross-country trip, it will be necessary to adjust for compass variance.
If not adjusted to account for compass variance, your compass could give false readings.
To adjust for compass variance, do the following:
1. Find your current location and variance zone number on the following zone map.

2. Press and hold the on/off button for six seconds. Release the button when (FOR ZONE) is displayed. The number shown is the current zone number.
3. Scroll through the zone numbers that appear in the window on the mirror by pressing the on/off button. Once you find your zone number, release the button. After about four seconds, the mirror will return to the compass display, and the new zone number will be set.
See also:
Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
...
Driver Efficiency Gauge
Driver Efficiency Gauge
This gauge assists the driver in
operating the vehicle more
efficiently and will vary based on
driver input.
See Driver Efficiency Gauge for more information. ...
Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog or frost from the rear window.
(Rear Defogger): Press to turn the
rear window
defogger on or off. An indicator light below the button ...
