Home > VansAirForceForums

-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

VAF on Twitter:

Old 06-09-2022, 05:46 PM
BillL's Avatar
BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 6,849
Default GTN 650 Error Message - Data Source ??

I got this message today on a flight and the pilot manual said "Dealer Service"

Can anyone enlighten me on the issue and implications for "service"?

Click image for larger version

Name:	IMG_6530.jpg
Views:	80
Size:	430.3 KB
ID:	26858
Reply With Quote
Old 06-09-2022, 06:49 PM
bjdecker's Avatar
bjdecker bjdecker is offline
Join Date: Jun 2005
Location: Georgetown, TX
Posts: 1,372

How is your GTN configured? RS-232 i/o's, HSDB, ARINC, etc.

There's a section in the install manual that refers to external heading sources...
Brian Decker
RV-7 (Flying)
Reply With Quote
Old 06-09-2022, 07:14 PM
BillL's Avatar
BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 6,849

Brian, good comment , I'll check the wiring diagram for that specifically.

It just appeared after 230 hrs of (seemingly) perfect operation.
Reply With Quote
Old 06-13-2022, 06:32 AM
BillL's Avatar
BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 6,849
Default 650 "DATA SOURCE" Message .. UPDATE ..

My first question is what changed and why now? Here is the background and event chain leading to a 650 error Message that was not real.

Discovery - the G3X is much slower than the 650 in the boot cycle. Although I have all the latest (I think SW) the message appeared.

My start sequence is battery-backup on- to boot the G3X then master on and start sequence. Well, my TWC IBBS battery is not charging (2nd failure) and the G3X has not completed the boot before I switched on the avionics (includes the 650). I had already done all my preflight checks and taxied up-shut down for a passenger. The restart sequence was faster than normal cold sequence. And . . I did not wait for the full g3x boot to continue in the checklist switch activations.

Yesterday, I watched the info errors on the G3X and found the RS232 and ARINC 429 connection errors disappear late in the boot sequence as linkage was established. It took longer than I thought. When errors were allowed to clear before turning on the 650 (Avionics), there were no error messages on the 650.

Now what I believe to have happened (but will discuss with Garmin)- - I think that the error generating SW code for the" Data Source: HDG" is encountered and posted to the screen before the data buss connection handshaking is completed, but is not revisited after the connection is made, i.e. is not constantly being checked (?). This allowed my direction up map to display properly but the error message would not disappear even though it was no longer valid. The location of the error message posting location in the line of boot code was before the ARINC could be finished due to the slower speed of the G3X booting process.

1) Charge/Replace IBBS battery.
2) Discuss SW with Garmin as to why the message did not disappear once "source" was connected so others won't get the message.
3) Evaluate panel change to provide more reliable IBBS, and alternative to IBBS to maintain line voltage to G3X in addition to IBBS - i.e. voltage stabilizer.

Thanks for listening.
Reply With Quote
Old 06-13-2022, 08:04 AM
Carl Froehlich's Avatar
Carl Froehlich Carl Froehlich is offline
Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 3,941

I too worry about avionics being sensitive to engine start. For my dual SkyView and GTN-650 install, start process is:
- Left avionics on. This powers up one SkyView display (with EMS) and Comm #2 (the Dynon radio).
- Engine start. I have never had a brown out of the one powered SkyView during engine start.
- After start the right avionics comes on. This brings up the second SkyView display and the power hog GTN-650. Now overlay the cost of the GTN-650 and I have good reason to baby it.

Note - I have dual PC-625 batteries on independent busses. Both batteries are on line for engine start and for all normal operation. I do not have any backup batteries as the design eliminates the need.

Reply With Quote
Old 06-13-2022, 08:20 AM
Walt's Avatar
Walt Walt is online now
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,917

Do you have a touch or non-touch system?
Generally the BU bat does not power the ARINC box, it comes up the same time as power is supplied to the 650/750, never seen that error but I alway wait for the AHRS to complete its alignment before start. So I suppose if heading info is not available (from G3X) when you boot the 650 it flags it.
Good luck getting the code changed on the 650.
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 2000+ hrs, New Titan IO-370, Bendix Mags, MTV-9 prop
Website:, Email:, Cell: 972-746-5154
Reply With Quote
Old 06-13-2022, 04:57 PM
BillL's Avatar
BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 6,849

Non-touch . . . Fingers crossed on SW, Walt, no expectations though.

Carl, The dual battery would help the voltage drop drastically. Our avionics are not like industrial mobile electronics like Deere and Cat. The engine ECM would work down to 7 volts and up to 47 volts. You can not have hydraulics and other things going wild on a 30 ton excavator. My vote would be all aircraft electronics to be the same way, but . . . no clout.
Reply With Quote
Old 07-28-2022, 11:35 PM
azonic75 azonic75 is offline
Join Date: Dec 2010
Location: Salem, OR
Posts: 138
Default did this end up requiring?

Did you end up having to send this to garmin?

RV-8a Flying
RV-10 Building
J-5A Flying
Extra 300 flying
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 03:29 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.