Messages - Garmin GNC 255 Pilot's Manual

4.3

Messages

When a Message has been issued by the unit, the Message will be shown on
the display. After viewing the messages, touch the ENT key to acknowledge the
message and return to the previously viewed page. An acknowledged message
will not be redisplayed even if the condition persists. Messages provide an aid to
troubleshooting system operation.
Press ENT To
Acknowledge
Message
COM RADIO -
Com radio needs
service.
COM RADIO -
Com radio may be
inoperative.
COM RADIO -
Com overtemp
or undervoltage.
Reducing
transmitter power.
COM RADIO -
Com locked to
121.5 MHz. Hold
remote com
transfer key to exit.
4-4
Figure 4-1 Message - Com PTT Key Stuck
Description
The com radio is
reporting that it needs
service. The com radio
may continue to
function.
The com radio is not
communicating properly
with the system.
Com radio is
in overtemp or
undervoltage mode
and transmitting power
has been reduced to
prevent damage to the
com radio. Radio range
will be reduced.
Com radio is locked to
121.5 MHz.
Garmin GNC 255A/255B Pilot's Guide
Action
Cycle the power to the COM radio.
Contact dealer for service.
Press and hold the volume knob or
the external com remote transfer
(COM RMT XFR) switch, if installed
– this will force the com radio to
121.5 MHz. Contact dealer for
service.
Decrease length of com
transmissions, decrease cabin
temperature and increase cabin
airflow (especially near the GTN).
Check aircraft voltage and reduce
electrical load as necessary.
Contact dealer for service if this
message persists.
The external com remote transfer
(COM RMT XFR) switch has been
held and the com radio is tuned to
121.5. To exit this mode, hold the
com remote transfer (COM RMT
XFR) switch for two seconds.
Message
190-01182-01 Rev. A