2007 GMC Sierra 1500 Pickup Owner's Manual - Page 180

Automatic Dimming Rearview Mirror with Compass and Temperature Display If the vehicle is equipped with an automatic mirror, it will, when on, automatically dim to the proper level to minimize glare from lights behind you after dark. The mirror also includes a display in the upper right corner of the mirror face. The compass reading and the outside temperature will both appear in the display at the same time. The dual display can be turned on or off by briefly pressing either the TEMP or the COMP button. Temperature Display The temperature can be displayed by pressing the TEMP button. Pressing the TEMP button once briefly, will toggle the temperature reading on and off. To alternate the temperature reading between Fahrenheit and Celsius, press and hold the TEMP button for approximately four seconds until the display blinks F and C. Press and release the TEMP button to toggle between the Fahrenheit and Celsius readings. After approximately four seconds of inactivity, the display will stop blinking and display the last selection made. If an abnormal reading is displayed, for an extended period of time, please consult your dealer. Under certain circumstances, a delay in updating the temperature is normal. 180