2010 Honda Civic Owner's Manual - Page 172

Playing the XM Radio (Models with navigation system) The XM satellites are in orbit over the equator; therefore, objects south of the vehicle may cause satellite reception interruptions. To help compensate for this, ground-based repeaters are placed in major metropolitan areas. Satellite signals are more likely to be blocked by tall buildings and mountains the farther north you travel from the equator. Carrying large items on a roof rack can also block the signal. SATELLITE Signal may be blocked by mountains or large obstacles to the south. Signal weaker in these areas. Depending on where you drive, you may experience reception problems. Interference can be caused by any of these conditions: Driving on the north side of an east/west mountain road. GROUND REPEATER Driving on the north side of a large commercial truck on an east/west road. 166