See also:

Clearing the programmed information
Individual buttons cannot be cleared. However, to clear all programming, press and hold the two outside buttons and release when the indicator light begins to flash (approximately 20 seconds). ...

Compass display (if so equipped)
This unit measures terrestrial magnetism and indicates the direction of the vehicle’s heading. With the ignition switch placed in the ON position, press the button as described in the chart b ...

Trailer brakes
If your trailer is equipped with a braking system, make sure it conforms to federal and/or local regulations and that it is properly installed. Never connect a trailer brake system directly ...