Volvo XC90: Audio, media and internet / HD Radio™ sub-channels
In many cases, a main HD Radio station (FM wavebands only) will also have sub-channels
offering additional types of programming or music.
Sub-channels

Example of an HD Radio station with sub-channels
If any sub-channels are available, they will listed below the main channel on
the screen. In this example, WILD-FM HD2 is a sub-channel.
Selecting sub-channels
To listen to a station's sub-channel(s), tap the station on the screen or press
the forward/ back arrow keys on the right-side steering wheel keypad or below the
screen.
Sub-channels can also be saved as radio favorites.
If you tap a sub-channel favorite, it may take up to 6 seconds before
the channel becomes audible. If you tap a station while you are out of digital range
of the transmitter, No reception will be displayed.
HD Radio is deactivated when the car leaves the factory.
When listening to an HD Radio station and driving through areas with weak HD
signals (fringe areas), you may experience that the radio repeatedly switches between
analog/digital and digital/analog reception...
Limitations
Main channel vs. sub-channels (FM only): The main channel is the
only channel that can receive in hybrid mode (both digital and analog)...
Other information:
(Option/accessory)
If the vehicle is equipped with Sensus Navigation*, speed-related information
will be provided in the following situations:
In cases where the speed limit is given indirectly, e.g. signs for highways
or other major roads.
If a previously detected speed sign is deemed to be no longer valid and
no new sign has been passed...
If safety mode has been set, it may be possible to reset the system in order
to start and move the vehicle a short distance, for example, if it is blocking traffic.
Starting the vehicle when it is in safety mode
Check the vehicle for damage, particularly for fuel leakage...