GM Service Manual Online
For 1990-2009 cars only

If your vehicle has this feature, the driver's and/or passenger's outside mirror will adjust to a preset tilt position while the vehicle is in REVERSE (R) gear. Curb view assist may be useful when you are parallel parking. The mirror(s) will return to normal position when the vehicle is shifted out of REVERSE (R) gear. Automatic mirror movement in either direction will follow a short delay.

To change the tilt position, adjust the mirror while the vehicle is in REVERSE (R) gear with the engine running, the parking brake engaged and the brake pedal pressed. The new position will be saved into memory once the vehicle is shifted out of REVERSE (R).

You may be able to enable/disable this feature through the Driver Information Center (DIC). See "Mirror Curb View Assist" under DIC Operation and Displays .