Garmin G1000 Pilot's Manual page 121

AUTO-TUNING NAV FREQUENCIES ON APPROACH ACTIVATION
The primary NAV frequency is auto-tuned upon loading a VOR or ILS/Localizer approach.
NOTE:
When an ILS/LOC approach has been activated in GPS Mode, the system switches to NAV Mode
NOTE:
as the final approach course is intercepted (within 15 nm of the FAF). See the GPS Navigation section for
details.
NAV frequencies are automatically loaded into the NAV Frequency Box on approach activation.
When loading or activating a VOR or ILS/LOC approach, the approach frequency is automatically transferred
to a NAV frequency field as follows:
• If the current CDI source is GPS, the approach frequency is transferred to the NAV1 active frequency field.
The frequency that was previously in the NAV1 active frequency field is transferred to standby.
• If the current CDI source is GPS, and if the approach frequency is already loaded into the NAV1 standby
frequency field, the standby frequency is transferred to active.
• If the current CDI source is NAV1 or NAV2, the approach frequency is transferred to the standby frequency
fields of the selected CDI NAV radio.
190-00498-01 Rev A Garmin G1000 Pilot's Guide for Cessna Nav III
AUDIO PANEL AND CNS
4-23