Wanna Update your Garmin GPS175/GNC355/GNX375 Main software v. 3.30 ?

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
My Garmin: GPS175 Experimental
re: Garmin Main software 3.30 update for GPS175/GNX375 units

I spent over an hour trying to find out how and where to get the download file on the Garmin websites to do this update on my Garmin GPS175 nav. Garmin must enjoy making it difficult to do this? Here's what I did to generate the SD card install file:
(SB install instruction .pdf attached)

(2026) Service Bulletin 26085 Rev A: GPS 175/GNX™ 375/GNC® 355 Main Software Version 3.30 and GNX 375 Transponder Software Version 2.90
Link: (SB General Description)

Where to get the install file: (link below)
The following content is available for registered users:
Manuals
Software
Service & Installation Bulletins
Service Communiques & Letters


Doc ID: SB26089 RevA (Service Bulletin, Install Instructions)

*Experimental* GPS175/GNC355/GNX375 TSO Software - Main v3.30

then
Downloaded and Installed below file on my Windows PC to generate the install file on a Mini-SD card, then load into your Garmin GPS175/GNC355/GNX375
(remember 32GB max SD card)

(download this file)
GPS 175/GNX™ 375/GNC® 355 TSO Software - Main v3.30, Transponder v2.90 006_b3353_0e_a.zip
(unzip this to generate the actual install files)

ENJOY!
 

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Last edited:

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
re: Garmin Main software 3.30 update

I spent over an hour trying to find out how and where to get the download file on the Garmin websites to do this update on my Garmin GPS175 nav. Garmin must enjoy making it difficult to do this? Here's what I did to generate the SD card install file:
(SB install instruction .pdf attached)

(2026) Service Bulletin 26085 Rev A: GPS 175/GNX™ 375/GNC® 355 Main Software Version 3.30 and GNX 375 Transponder Software Version 2.90
Link: (SB General Description)

Where to get the install file: (link below)
The following content is available for registered users:
Manuals
Software
Service & Installation Bulletins
Service Communiques & Letters


Doc ID: SB26089 RevA (Service Bulletin, Install Instructions)

*Experimental* GPS175/GNC355/GNX375 TSO Software - Main v3.30

then
Downloaded and Installed below file on my Windows PC to generate the install file on a Mini-SD card, then load into your Garmin GPS175/GNC355/GNX375
(remember 32GB max SD card)

(download this file)
GPS 175/GNX™ 375/GNC® 355 TSO Software - Main v3.30, Transponder v2.90 006_b3353_0e_a.zip
(unzip this to generate the actual install files)

ENJOY!
 

F18Sailor

New Member
Joined
Mar 20, 2025
Messages
19
This is a Dynon forum...not sure what you were expecting....and yes, Garmin bury their update pages. I expect a few to be coming out over the next few weeks with the AXIS release.
 

Biggiesauls

New Member
Joined
Jan 9, 2024
Messages
22
Location
NE Texas
This is a Dynon forum...not sure what you were expecting....and yes, Garmin bury their update pages. I expect a few to be coming out over the next few weeks with the AXIS release.
If we are real lucky, some gps175 units might be pulled from some Dynon panels once the Dynon navigator changes from vaporware to shipping.
 

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
This is a Dynon forum...not sure what you were expecting....and yes, Garmin bury their update pages. I expect a few to be coming out over the next few weeks with the AXIS release.

F18 Sailor: I'm probably wrong, but I was just assuming there's quite a few people that use Garmin navigation units (mine is GPS175, IFR approved) linked into their Skyview units. I think it's a pretty important update (imo) with the visual approach VNAV update (and other fixes).
 
Last edited:

Rhino

Well-Known Member
Joined
Jul 20, 2009
Messages
1,905
Presumably it's because Mac only has a 9% market share, so there's relatively few Macs out there to support, compared to PCs. The weird thing is that market share doesn't seem to matter when it comes to mobile apps. Apple devices have only a 32% market share in the mobile market, compared to 69% for Androids. And yet, there are lots of aviation apps that are only written for Apple devices. Go figure.
 

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
Presumably it's because Mac only has a 9% market share, so there's relatively few Macs out there to support, compared to PCs. The weird thing is that market share doesn't seem to matter when it comes to mobile apps. Apple devices have only a 32% market share in the mobile market, compared to 69% for Androids. And yet, there are lots of aviation apps that are only written for Apple devices. Go figure.
yeah, doesn't make a lot of sense for Garmin to not support Apple devices, especially for this system update. I have an Apple iPad in my RV7 so that I can use Foreflight, which can send and receive flight data to the GPS 175.
 

PYoder

Member
Joined
Nov 3, 2013
Messages
66
Location
KOSU
re: Garmin Main software 3.30 update for GPS175/GNX375 units

I spent over an hour trying to find out how and where to get the download file on the Garmin websites to do this update on my Garmin GPS175 nav. Garmin must enjoy making it difficult to do this? Here's what I did to generate the SD card install file:
(SB install instruction .pdf attached)

(2026) Service Bulletin 26085 Rev A: GPS 175/GNX™ 375/GNC® 355 Main Software Version 3.30 and GNX 375 Transponder Software Version 2.90
Link: (SB General Description)

Where to get the install file: (link below)
The following content is available for registered users:
Manuals
Software
Service & Installation Bulletins
Service Communiques & Letters


Doc ID: SB26089 RevA (Service Bulletin, Install Instructions)

*Experimental* GPS175/GNC355/GNX375 TSO Software - Main v3.30

then
Downloaded and Installed below file on my Windows PC to generate the install file on a Mini-SD card, then load into your Garmin GPS175/GNC355/GNX375
(remember 32GB max SD card)

(download this file)
GPS 175/GNX™ 375/GNC® 355 TSO Software - Main v3.30, Transponder v2.90 006_b3353_0e_a.zip
(unzip this to generate the actual install files)

ENJOY!
I have a 375 - installed in certified Bo - is there any way to access the software download to update mine without going to dealer? I've attempted to follow your instructions but get stopped short trying to find download file?!?!?

26089 sends me to 'loader card creation' which sends me to 'dealer resource center' - which, of course, i am not.
 
Last edited:

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
I have a 375 - installed in certified Bo - is there any way to access the software download to update mine without going to dealer? I've attempted to follow your instructions but get stopped short trying to find download file?!?!?

26089 sends me to 'loader card creation' which sends me to 'dealer resource center' - which, of course, i am not.
Good question Pyoder. I thought I read that certified units have to be done by an approved Garmin dealer. I suggest giving Garmin a call to confirm that.

Mine: Garmin 175 Experimental
 
Last edited:

PYoder

Member
Joined
Nov 3, 2013
Messages
66
Location
KOSU
Good question Pyoder. I thought I read that certified units have to be done by an approved Garmin dealer. I suggest giving Garmin a call to confirm that.
Yes, They advertise that units installed in certified aircraft must be done by a dealer. I'm trying to find a way around that - was not obvious from your post what kind of plane you had.
 

PhilzSkyHdx

Member
Joined
Oct 11, 2025
Messages
44
Yes, They advertise that units installed in certified aircraft must be done by a dealer (or A&P) I'm trying to find a way around that - was not obvious from your post what kind of plane you had.
Ya I didn't specify that (mine is Experimental) in my original post. thanks
 
Last edited:

Avee8or

New Member
Joined
Jan 5, 2025
Messages
14
Yes, They advertise that units installed in certified aircraft must be done by a dealer. I'm trying to find a way around that - was not obvious from your post what kind of plane you had.
The Garmin website just refers to the applicable FAR, implying that the update could be done by A&P/IA. Did you get the dealer requirement in a conversation with Garmin? My GPS is in a C170, and I have no dealer nearby.
 
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