HONDA 2008 Odyssey - Manual (Page 248)

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.
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.
Driving on the north side of a
large commercial truck on an
east/west road.
Driving in tunnels.
Driving on a road beside a vertical
wall, steep cliff, or hill to the south
of you.
Driving on the lower level of a
multi-tiered road.
Driving on a single lane road
alongside dense trees taller than
50 ft. (15 m) to the south of you.
Playing the XM Satellite Radio (U.S. EX and all EX-L models without navigation system)
242
SATELLITE
GROUND REPEATER
Signal weaker in these areas. Signal may be blocked by
mountains or large obstacles
to the south.