See also:

Turn Signals when Towing a Trailer
The turn signal indicators on the instrument panel flash whenever signaling a turn or lane change. Properly hooked up, the trailer lamps also flash, telling other drivers the vehicle is turni ...

Programming with a Recognized Transmitter (Keyless Access Vehicles Only)
A new transmitter can be programmed to the vehicle when there is one recognized transmitter. To program, the vehicle must be off and all of the transmitters, both currently recognized and new ...

Your Responsibility
Increase the volume of the radio if the OnStar Advisor cannot be heard. If the light next to the OnStar buttons is red, the system may not be functioning properly. Push and request a vehicle diagnos ...