1200 E. 151st Street
Olathe, KS 66062
913-397-8200
SERVICE BULLETIN
NO.: 21135 Rev A
TO:
All Garmin Aviation Service Centers
DATE:
December 22, 2021
SUBJECT:
GTX™ 35R/GTX 45R/GTX 3X5 Series Main Software Version 2.65 and ADS-B Software
Version 3.31
CERTIFICATION
AUTHORIZATION:
TSO Authorization (see Approval section for details)
TSO authorization does not provide installation airworthiness approval. Separate installation airworthiness approval is required for type
certified aircraft. Notification of revision to any Garmin STC(s) will be provided under a separate service bulletin.
______________________________________________
PRODUCTS AFFECTED
The following GTX 35R/GTX 45R/GTX 3X5 series units are affected:
Table 1. Products Affected
Model
Appliance P/N
GTX 325
011-02974-00
GTX 335
011-03300-0( )
GTX 335 NV
011-03300-2( )
GTX 335 GPS
011-03300-4( )
GTX 335R
011-03301-0( )
GTX 335R GPS
011-03301-4( )
GTX 335D
011-04331-00
GTX 335DR
011-04332-00
GTX 345
011-03302-0( )
GTX 345 GPS
011-03302-4( )
GTX 345R
011-03303-0( )
GTX 345R GPS
011-03303-4( )
GTX 345 NV
011-03302-2( )
GTX 345 NV, GPS
011-03302-6( )
GTX 345D
011-04333-00
GTX 345DR
011-04334-00
GTX 35R
011-04286-0( )
GTX 45R
011-04287-0()
© 2021
Garmin Ltd. or its subsidiaries
All Rights Reserved
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and provided further that any unauthorized commercial distribution of this document or any revision hereto is strictly prohibited.
Service Bulletin 21135
December 22, 2021
Page 1-12
Revision A
PURPOSE
GTX 35R/GTX 45R/GTX 3X5 Series Main Software Version 2.65 contains the following changes:
•
•
•
•
•
•
•
•
•
•
•
Fixed squat switch issue documented in Garmin Service Advisory 20123. Updated the air/ground
algorithm to report the previous power cycle air state for the first five seconds after power-up
when a squat switch is installed.
Improved squitter fault detection to be more tolerant of momentary interruptions to nominal squitter
transmissions.
Expanded the flight ID entry processing to add a flight ID history which can track up to four
previously-entered flight ID values on panel-mounted units.
Added the GAE 12 altitude encoder as a supported source of pressure altitude on GTX 35R and
45R units.
Expanded the serial output port configuration to support a new MX Series Format 3 configurable
output format, available for units with ADS-B In capability.
Expanded discrete output functionality to include a new Altitude Valid discrete output function,
which is asserted when the GTX is receiving valid pressure altitude data and is in a mode that
enables transmission of altitude data.
Updated the equipment status discrete output function conditions to not activate on the pressure
altitude input warning when the Altitude Valid discrete output function is configured.
Expanded unit configuration to support on-ground power up mode configuration, which allows the
unit to be configured to power up in a specific transponder mode when on-ground.
Expanded audio message functionality to include autopilot alerts as a new class of aural
messages, which includes a single new aural alert message “Autopilot Off”. The audio software
was also updated to support this change.
Expanded discrete input functionality to add Autopilot Off 1 and Autopilot Off 2 as new discrete
input functions.
Updated the altitude deviation display configuration to allow an acceptable range of 150 ft to 999 ft.
GTX 35R/GTX 45R/GTX 3X5 Series ADS-B Software Version 3.31 contains the following changes:
•
•
•
Improved 1090ES ADS-B/ADS-r/TIS-B message reception processing to ensure that 1090ES
ADS-B/ADS-R/TIS-B targets are correctly displayed on diversity units.
Added a new serial output MX Series Format 3 to more accurately provide FIS-B data to G1000®
displays running 12.XX, 13.XX, 14.XX, and 15.XX software versions that support FIS-B.
Improved the consistency of HSDB ground uplink transmissions.
DESCRIPTION
This service bulletin describes the process for upgrading GTX 35R/GTX 45R/GTX 3X5 Series units to
Main Software Version 2.65 and ADS-B Software Version 3.31.
COMPLIANCE
Optional: This Service Bulletin may be incorporated at the owner’s discretion and is not warranty
reimbursable.
APPROVAL
TSO authorization does not provide installation airworthiness approval. Separate installation
airworthiness approval is required for type certified aircraft. Notification of revision to any Garmin
STC(s) will be provided under a separate service bulletin.
GTX 35R/GTX 45R/GTX 3X5 Series Main Software Version 2.65 and ADS-B Software Version 3.31 are
TSO authorized. Refer to the applicable installation manual for additional approvals. The change from
main software version 2.60 and ADS-B software version 3.22 are both minor per 14 CFR 21.619.
Service Bulletin 21135
December 22, 2021
Page 2-12
Revision A
DOCUMENTATION CONSIDERATIONS
The current revision of the GTX 3X5 Series Pilot’s Guide (Garmin P/N 190-01499-00) Rev G is applicable.
Pilot Guides are available at www.garmin.com/manuals.
REFERENCES
Table 2. References
Document
Number
Revision
(or later)
190-01499-00
G
GTX 3X5 Series Transponder Pilot’s Guide
190-01499-01
A
GTX 3X5 Series Transponder G1000 Pilot’s Guide
190-01499-02
19
GTX 3X5 Transponder TSO Installation Manual
190-01499-33
E
GTX 3X5 Installation Tool Guide
190-01487-12
B
GTX 345 Quick Connectivity Setup Guide
190-01499-09
F
GTX 345 Declaration of Conformity
190-01795-01
D
GTX 345 Important Safety and Product Information
190-01499-04
6
GTX 35R/45R Transponder TSO Installation Manual
Description
All documents described in this bulletin are available at no cost in the Dealer Resource Center on the
Garmin website https://dealers.garmin.com.
MANPOWER
One (1) hour labor.
WARRANTY INFORMATION
This modification is not warranty reimbursable.
Service Bulletin 21135
December 22, 2021
Page 3-12
Revision A
SOFTWARE INSTALLATION AND VERIFICATION INSTRUCTIONS
Part One: Software Upgrade Procedure
NOTE
GTX 35R/GTX 45R/GTX 3X5 Series transponder software is updated with the Install Tool
operating on a PC or laptop computer and USB cable. There is no G1000 system loader
card.
1. From the Garmin Dealer Resource Center, download the following onto a PC or laptop:
• GTX 35R/GTX 45R/GTX 3x5 Field Release (006-B2466-0K)
• GTX 35R/GTX 45R/GTX 3x5/3000 Install Tool version 4.25 (006-A0271-45)
(or later version)
2. Install the Install Tool.
3. Open the executable file (006-B2466-0K_0A.exe).
4. Connect a USB cable from the PC or laptop to the USB connector attached to the
GTX 35R/GTX 45R/GTX 3X5 connector backplate.
5. Attach the aircraft to ground power.
6. Energize the unit.
NOTE
Take steps to prevent accidental power disruptions to the unit during the software loading
process.
7. Open the Install Tool.
8. Select Configure Transponder.
Figure 1. GTX Install Tool
Service Bulletin 21135
December 22, 2021
Page 4-12
Revision A
9. Wait for the unit to connect.
Figure 2. Connected Unit
10. Select GTX.
11. Select Configuration.
12. Select Save.
NOTE
The unit’s configuration parameters are maintained through a software upload. Saving the
configuration before the upload provides a quick way to analyze configuration changes
that need to be addressed with the update.
Figure 3. Configuration Save
13. Choose a location to save the unit’s configuration.
14. Close the configuration window.
Service Bulletin 21135
December 22, 2021
Page 5-12
Revision A
15. Select Load Software.
Figure 4. GTX Install Tool
16. Make sure the unit is online.
Figure 5. Connection Status
Service Bulletin 21135
December 22, 2021
Page 6-12
Revision A
17. Select Browse.
18. Locate the GTX 35R/GTX 45R/GTX 3x5 Field Release (006-B2466-0K_0A.gca).
Figure 6. Software Upload
Service Bulletin 21135
December 22, 2021
Page 7-12
Revision A
19. Select Auto-select.
Figure 7. Auto-select
20. Select Upload.
NOTE
Individual items will be marked as complete as they are installed. If items fail, repeat the
upload process. A message box will appear once the upload is complete.
Service Bulletin 21135
December 22, 2021
Page 8-12
Revision A
21. Once the upload is complete, make sure the software part numbers and versions on the unit match
the ones in the GTX 3x5 field release file.
Figure 8. Software Load Complete
22. Select Exit.
Part Two: Software Upload Checkout
Review New Configuration Items
A system software update may add new configuration items. Values for new items should be determined
and assigned. Configuration changes for each system software version are documented in the GTX 3X5
TSO Installation Manual and the GTX 3x5 Installation Tool Guide.
Review new configuration items by comparing the unit configuration to the configuration file saved before
the upload.
NOTE
Differences are highlighted in yellow.
1.
2.
3.
4.
Select Configure Transponder on the GTX Install Tool.
Select GTX.
Select Configuration.
Select Compare to file.
Figure 9. Compare to File
Service Bulletin 21135
December 22, 2021
Page 9-12
Revision A
5. Select the saved file in Part One.
6. Use the scroll bar to look through the configuration items and look for changes highlighted in
yellow.
Figure 10. Configuration Comparison
7. Set new configuration items as required.
Resolve Configuration Failures
A system software update may add additional restrictions on existing configuration, which could result in a
configuration failure. Follow these steps if a configuration failure exists after a software is loaded.
1. Compare configuration saved before the software load to the unit’s current configuration.
2. Highlighted items that exist in both configurations indicate a problem and will be set to their default
value.
3. Modify the configuration setting by changing its value and pressing set.
4. Set the configuration to the desired value.
When updating to system software version 2.60 or later, the following steps can be performed to ensure a
clean/valid configuration if the configuration fault persists:
1. Make sure configuration was saved before the upload.
2. Reset configuration using the GTX –> Configuration –> Reset menu item.
3. Load the previously saved configuration.
NOTE
If the configuration was not saved before the software upload, load the previous system
software version, save configuration, and then load desired system software again.
Service Bulletin 21135
December 22, 2021
Page 10-12
Revision A
Resolve Non-Volatile Memory Fault
After loading software, further action is needed under the following conditions:
•
•
•
System software was updated from version 2.02, 2.03, 2.05, or 2.10.
System software was updated to version 2.11 or later.
The unit is failed due to a non-volatile memory fault and configuration failure.
In this situation, RS232, A429, Discretes IO, and Altitude Source configuration will be defaulted due to an
incompatibility in discrete configuration. To resolve this issue, perform the following actions:
1. Connect to a unit and navigate to the discrete configuration page.
2. Assign discrete functions as desired.
3. Press the set button.
NOTE
If the desired discrete configuration is the default, assign an arbitrary discrete function and
press set. Then unassign that function, and press set again.
4. Cycle power to the transponder.
Part Three: Documentation Update Procedure (with the appliance installed)
Make entries in aircraft records in accordance with local aviation authority requirements to indicate this
bulletin has been completed.
Service Bulletin 21135
December 22, 2021
Page 11-12
Revision A
MATERIAL INFORMATION
NOTE
All files are available to download on the Dealer Resource Center dealers.garmin.com.
•
•
GTX 35R/GTX 45R/GTX 3x5 Field Release (006-B2466-0K)
GTX 35R/GTX 45R/GTX 3x5/3000 Install Tool version 4.25 (006-A0271-45)
(or later version)
GTX 35R/GTX 45R/GTX 3x5 Field Release (006-B2466-0K) contains the following:
Item
Part Number
Version
Public Keys
006-D7109-K0
2.00
Region List (Non-Diversity)
006-D7109-00
2.00
Region List (Diversity)
006-D7402-00
2.00
System
006-B1607-0L
2.65
Audio
006-D4910-07
2.52
FPGA (Non-Diversity)
006-C0153-22
2.20
FPGA (Diversity)
006-C0184-22
2.20
ADS-B Public Keys
006-D7336-K0
2.00
ADS-B System
006-B1797-1A
3.31
ADS-B FPGA
006-C0157-21
2.10
GPS
006-B1827-22
8.2
GPS Loader
006-B2349-00
2.0
The install tool only shows loadable regions that are applicable to the connected unit type.
Service Bulletin 21135
December 22, 2021
Page 12-12
Revision A