2003 GMC Yukon Owner's Manual - Page 134

Follow the proper steps to be sure your vehicle will not move. See Shifting Into Park (P) on page 2-35. If you are pulling a trailer, see Towing a Trailer on page 4-61. Automatic Dimming Rearview Mirror with OnStar®, Compass and Temperature Display Your vehicle may have this feature. When on, an electrochromic mirror automatically dims to the proper level to minimize glare from lights behind you after dark. Mirrors Manual Rearview Mirror Pull the tab under the mirror toward you to reduce glare from headlamps behind you after dark. Push the tab away from you for normal daytime operation. The mirror also includes a duel 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. P (On/Off): This is the on/off button. 2-40