Garmin GNC 255A, Pilot'S Manual

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190-01182-01 Rev. E Garmin GNC 255A/255B Pilot’s Guide 5-3
Troubleshooting
5.1 Messages
When a message has been issued by the unit, the message will be shown on the
display. After viewing the messages, press 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.
Display of Message
Messages
MESSAGE DESCRIPTION ACTION
COM RADIO -
COM radio needs
service.
The COM radio is
reporting that it needs
service. The COM radio
may continue to function.
Cycle the power to the
COM radio. Contact dealer
for service.
COM RADIO -
COM radio may be
inoperative.
The COM radio is not
communicating properly
with the system.
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.
COM RADIO -
COM overtemp or
undervoltage. Reducing
transmitter power.
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.
Decrease length of COM
transmissions, decrease
cabin temperature and
increase cabin airflow
(especially near the GNC).
Check aircraft voltage and
reduce electrical load as
necessary. Contact dealer
for service if this message
persists.
COM RADIO -
COM locked to 121.5
MHz. Hold remote COM
transfer key to exit.
COM radio is locked to
121.5 MHz.
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