2009 Honda Pilot Owner's Manual - Page 274

Playing the XM Satellite 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. Signal may be blocked by mountains or large obstacles to the south. Signal weaker in these areas. SATELLITE GROUND REPEATER 270 2009 Pilot