GTX 345 Failure

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Arrow115

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Chris
Has anyone ever had any issues with random inflight failures of their GTX 345? This has been going on for the past few months. It does appear random as we wont have any issues for a while and then it happens again. I attached a picture of the initial message. The only way to get it working is to power cycle the transponder. Pressing ALT or anything else doesn't help. It does show a message on the messages page that says "1090ES ADS-B OUT FAILED"
 

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Arrow115 said:
Has anyone ever had any issues with random inflight failures of their GTX 345? This has been going on for the past few months. It does appear random as we wont have any issues for a while and then it happens again. I attached a picture of the initial message. The only way to get it working is to power cycle the transponder. Pressing ALT or anything else doesn't help. It does show a message on the messages page that says "1090ES ADS-B OUT FAILED"
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I see it every-time there is no GPS lock on my GTN, (takes about a minute or two of no GPS lock to post the message) like turning it on in the hangar.

Is your GTX using an internal GPS receiver or one that is panel mounted like a GNS/GTN etc?

I may have seen it happen in flight maybe once or twice in 3 years.
 
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bnt83 said:
I see it every-time there is no GPS lock on my GTN, (takes about a minute or two of no GPS lock to post the message) like turning it on in the hangar.

Is your GTX using an internal GPS receiver or one that is panel mounted like a GNS/GTN etc?

I may have seen it happen in flight maybe once or twice in 3 years.
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My GTX is connected to my GTN 650. When this happens, its always inflight and the 650 appears to work as normal.
 
I’ve a GTX-345 with a Garmin GNU-430W as position source for almost 4 years, and have not seen any error. It’s been very reliable. What does Garmin say? Have you called them or checked with a good Av shop? Curious if this is related to the unit or the installation.
 
Any GPS testing areas nearby? Have you changed cell phones, or started carrying a SPOT locator recently? Which port on the 345 is receiving the position data? It could be a bad crimp in the connector on either the GPS or xponder end.
 
I am on the list for my avionics guy. He mentioned a possible bad connection as well. We shall see. I am going to get the firmware version numbers of the transponder and 650 to see if there are any updates that are available as well. Thanks for all the suggestions.
 
Does anyone know if there is some way to confirm that valid position data is being sent from the GPS and received by the xponder? For instance, the GMX and MX 20 have a flag that generates if the transponder isn't receiving valid data. There is also a system page you can look at. Does the 345 have some way of confirming valid pvt data is being received, other than a 1090es TX out fail message? That could be a n antenna or other fault, not necessarily bad data.
 
Thanks, but I still see no way to see some sort of valid data message. Looks like check source satellite lock, ring wiring, check configs. I suppose you could put a scope on the TX pin of the source and look for square waves. But no way for the gtx to confirm valid data.
 
Chip Sylverne said:
Does anyone know if there is some way to confirm that valid position data is being sent from the GPS and received by the xponder? For instance, the GMX and MX 20 have a flag that generates if the transponder isn't receiving valid data. There is also a system page you can look at. Does the 345 have some way of confirming valid pvt data is being received, other than a 1090es TX out fail message? That could be a n antenna or other fault, not necessarily bad data.
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I believe there is a diagnostics menu similar to GTN were you can watch the code being received on input ports live.

The fail messages are strange for sure, especially when they light up like a Christmas tree when turned on indoors. There isn't a damn thing wrong with it but you wouldn't know that.

The internal GPS versions must have GPS antenna connected and the keep alive wire hot to keep the thing from flashing "service soon", even if you aren't using that GPS receiver. (note: If you aren't using the internal GPS the keep-alive wire only needs to be hot when the transponder is on)
 
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My altitude encoder went tango uniform, I don't remember if I got an error message or not. I did get a letter from the FAA letting me know that my ABS-B had failed.....this was a couple years ago.
 
Well, we got it hammered out. The correct configs from an IFD to a gtx345 using the IFD as the ADS-B position sensor are IFD rs232 out ADSB+ (G2) to GTX rs232 in ADSB FMT 2. As a little e experiment, we tried GTX legacy 422 with a GMX 200. No go.
 
Chip Sylverne said:
Well, we got it hammered out. The correct configs from an IFD to a gtx345 using the IFD as the ADS-B position sensor are IFD rs232 out ADSB+ (G2) to GTX rs232 in ADSB FMT 2. As a little e experiment, we tried GTX legacy 422 with a GMX 200. No go.
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I will try this. I randomly get a similar message - just the "no 1090ES" part not the "failure" part. Posted about it a while back and never came up with a solution. Checked all the connections, but didn't think about adjusting configuration.
 
Had similar issue back in November. First flight it was intermittent. Second flight was a complete failure. The unit had failed, so it was returned to Garmin for a warranty repair.
 

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Did your avionics shop initiate the return to Garmin or is there a way to talk directly to them? My avionics shop told me that they have heard of this issue and Garmin is aware of it and it may be fixed in a future software update. I am pretty sure they are just trying to avoid troubleshooting the issue. On a related note, anyone have a recommendation for an avionics shop in the Houston area?
 
Arrow115 said:
Did your avionics shop initiate the return to Garmin or is there a way to talk directly to them? My avionics shop told me that they have heard of this issue and Garmin is aware of it and it may be fixed in a future software update. I am pretty sure they are just trying to avoid troubleshooting the issue. On a related note, anyone have a recommendation for an avionics shop in the Houston area?
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I recently had some upgrades done by Temple. Some may have other opinions, but as of right now, I'm satisfied.
 
My GTX 345 just failed with the "Transponder Failed No 1090ES TX" warning. It's on the way to Garmin for repair - just out of the 2 year warranty. My shop says Garmin will charge $1300 to fix, but the turnaround time is pretty fast - and the shop gave me a loaner meanwhile.
 
Our GTX failed with the same message. We also had to send it to Garmin.
 
To be clear, when you guys say your unit “failed” is there an actual failure notice or is it just giving you the “no 1090es” message periodically?
 
nrimmer said:
To be clear, when you guys say your unit “failed” is there an actual failure notice or is it just giving you the “no 1090es” message periodically?
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If you look at my post above it says “failed.” Additionally, I could not set a transponder code and ATC confirmed they were receiving no return from me.
 
nrimmer said:
To be clear, when you guys say your unit “failed” is there an actual failure notice or is it just giving you the “no 1090es” message periodically?
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upload_2020-11-25_8-55-42.png
 
Thanks. Haven’t seen that one - mine gives the occasional “no 1090ES” but never seen a total fail message
 
Here at Southern Avionics we have had to send multiple GTX 345s off to Garmin for repair for this Transponder Fail issue. It appears to be a problem with the GTX 345 unit. At times it will go away and seems to be working just fine then it fails again.
When the 345 is not receiving GPS position it will display the 1090ES/ADSB errors under messages. You This particular failure completely disables the squawk code entry and mode selection.
 
Interesting, Isaac. After Garmin fixes the 345's, does that solve the problem "forever," or do they fail again? Just wondering, since I have a 335, which is about the same unit and mine has failed with the same message. It was sent back to Garmin, repaired and reinstalled. Should I look forward to the same thing happening again? I went with Garmin rather than Appareo Stratus because I thought Garmin had a good track record, but maybe not. :(
 
I do not recall any of the GTX 345s failing again. Apparently it was the transmitter board in the transponders that had to be replaced. We had troubleshot the issue by updating software, using different antennas, etc. The challenging aspect of it all was that it would start working again and work for some time and then it would fail again.
I wouldn’t be surprised to see Garmin roll out a service bulletin for them in the future.
Garmin has some great products but they aren’t immune to some glitches here and there.
 
One additional PIREP: My GTX 335 failed in-flight with the same message. Once the message came up it would not go away even after turning it off and back on. After it cooled down for a few hours it came back online, but failed again on the next flight. This happened a couple months ago when the device was just under 2 years old and had only been used for about 100 hours. Garmin fixed it under warranty with about a week turn around time.
gtx-335-1.jpg gtx-335-2.jpg
 
Chip Sylverne said:
Any GPS testing areas nearby? Have you changed cell phones, or started carrying a SPOT locator recently? Which port on the 345 is receiving the position data? It could be a bad crimp in the connector on either the GPS or xponder end.
Click to expand...
I'll second that with the Spot. When I had my GTN 650 installed in 2017, I was losing GPS signal every 10 minutes for up to a minute, but just on some flights. It turned out it was the flights where I was carrying my Spot, and the outages corresponded to the Spot's position updates every 10 min.
 
My GTX 345 just failed with the "Transponder Failed No 1090ES TX" warning. It's on the way to Garmin for repair - just shy of 200 hrs and 3.5 years after install. My shop says Garmin will charge $1300 to fix.
 
It is very likely that they will just send your shop a refurbed unit with a different serial number. That is what they did with mine even with the original sill being under warranty.
 
Mine failed on a Thurs night with about 600 hrs on it. I called my avionics shop Fri morning. Said they can send it back for a flat rate repair for $1395.00 or they can get me a replacement for $1495.00 and not wait for the repair. I went with the replacement and had it shipped next day. I took my plane over the avionics shop Monday afternoon and they swapped it. Did it while a I watched and did not charge me any labor. Sucks!! I now have about 300 hrs on the replacement and all is good so far.
IMG_0700.JPG
 
They sold you a used one for $1,495?
 
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