Garmin 400W Series, Instructions Manual

400W Series 

190-01226-14 Rev. 3 

Instructions for Continued Airworthiness Bell 407 

Page 18 of 26 

Alert Text 

Possible Cause 

Solution 

CDI key stuck 



 The CDI key is stuck in the enabled 

(or “pressed”) state. Try pressing the 
CDI key again to cycle its operation. 



  Contact Garmin technical 

support. 

CDI key disabled 



 “Ignore CDI key” has been selected 

on the MAIN CDI/OBS CONFIG 
page. 



  Go to the MAIN CDI/OBS 

CONFIG page and deselect 
“Ignore CDI key” 

Check unit cooling 



 The 400W Series unit has detected 

excessive display backlighting 
temperature.  The backlighting has 
been automatically dimmed to 
reduce the temperature.   



  Check for adequate ventilation 

or check cooling airflow. Refer to 
Section 2.7 of the Installation 
Manual. 

COM has failed (420W and 
430W only) 



 The unit has detected a failure in its 

communications transceiver. 



  Contact Garmin technical 

support. 

COM is not responding  
(420W and 430W only) 



 Internal  system-to-system 

communication between the main 
processor and the COM transceiver 
has failed.  Operational status of the 
COM transceiver is unknown. 



  Contact Garmin technical 

support.  If the COM board is still 
working, it will automatically tune 
to 121.500 MHz. Transmit and 
receive functions may still 
operate regardless of the 
displayed frequency. 

COM needs service  
(420W and 430W only) 



 The unit has detected a failure in its 

communications transceiver.  The 
COM transceiver may still be usable.



  Contact Garmin technical 

support 

COM push-to-talk key stuck 
(420W and 430W only) 



 The external push-to-talk (PTT) 

switch is stuck in the enabled (or 
“pressed”) state.  



  Try pressing the PTT switch 

again to cycle its operation. 



 Wiring is incorrect. 



 Check Wiring 

COM remote transfer key is 
stuck (420W and 430W only) 



 The remote COM transfer switch is 

stuck in the enabled (or “pressed”) 
state.  



  Try pressing the switch again to 

cycle its operation.  



  Verify the wiring is correct. 



  If the message persists, contact 

Garmin technical support. 

COM transfer key stuck  
(420W and 430W only) 



 The COM flip-flop key is stuck in the 

enabled (or “pressed”) state. 



  Try pressing the switch again to 

cycle its operation. 



  If the message persists, contact 

Garmin technical support. 

COM transmitter power has 
been reduced (420W and 
430W only) 



 The unit has detected excessive unit 

temperature. The COM transceiver 
transmit power has been 
automatically reduced to compensate 
for the condition. 



  Check for adequate ventilation 

or check cooling airflow. Refer to 
Section 2.7 of the Installation 
Manual. 



 Insufficient voltage level 



  Check the input voltage 

Configuration error - Config 
service req’d 



 The configuration information has 

been lost or corrupted. 



  Reconfigure the unit 

Data transfer cancelled 
(crossfill is busy) 



 An attempt to transfer flight plan data 

during a unit-to-unit crossfill was 
cancelled.  



  The host unit is busy. Wait until 

any previous crossfill operation 
is complete, before reattempting 
the transfer. 

Data transfer cancelled (data 
invalid) 



 An attempt to transfer a single user 

waypoint during a unit-to-unit crossfill 
was cancelled.  No waypoint was 
specified on the Crossfill Page.   



  Select a user waypoint and re-

attempt the transfer.