Random “no 1090es” message GTX 335

[nrimmer]

After several successful flights with a new GTX 335 installed and no errors (except air-on-ground) I have started randomly getting the error message “no 1090ex”. It was self installed with my A&P and then calibrated by our avionics shop.

The error has always resolved within a few minutes. In case it matters I am flying on the edge of a mode C ring. The error always seems to be when flying well outside of the mode c area and at lower altitudes near the Class G/E transition (1,000-1,500’)

Any suggestions?

 

[bnt83]

After several successful flights with a new GTX 335 installed and no errors (except air-on-ground) I have started randomly getting the error message “no 1090ex”. It was self installed with my A&P and then calibrated by our avionics shop.

The error has always resolved within a few minutes. In case it matters I am flying on the edge of a mode C ring. The error always seems to be when flying well outside of the mode c area and at lower altitudes near the Class G/E transition (1,000-1,500’)

Any suggestions?

http://static.garmin.com/pumac/190-00734-11_06.pdf

 

[Floyd]

Sounds like an antenna or wiring problem or possible GPS issue. I will see that message if I power up in the hangar and the gps cannot see the satellites.
As char above says contact Garmin.

 

[Indiana_Pilot]

I would check the coax for both transponder and GPS antenna.. a multimeter will quickly determine if you have a good cable or a short..

 

[Checkout_my_Six]

Sounds like an antenna or wiring problem or possible GPS issue. I will see that message if I power up in the hangar and the gps cannot see the satellites.
As char above says contact Garmin.

WASS antennas are 9v powered, active. This is a classic loss of ground plane at the antenna. It’s either internal or external at the antenna. Most times replacing the GPS antenna fixes it.

 

[nrimmer]

WASS antennas are 9v powered, active. This is a classic loss of ground plane at the antenna. It’s either internal or external at the antenna. Most times replacing the GPS antenna fixes it.

Thanks for the suggestions. I will check it out and report back

 

[nrimmer]

It was in fact a bad antenna connection. I had a thin aluminum bezel mounted in between the transponder face and the tray to cover the gap around the tray. This was keeping the transponder from being fully inserted and must have been right on the edge of an antenna connection. Removed the bezel and have no more problems. Even avoided the air-on-ground error for the first time.