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GNX 375 NEEDS SERVICE

Bart

Well Known Member
Has anyone else ever had this error? "GNX 375 NEEDS SERVICE" It's hard to find the message in the documentation but I found it buried in the maintenance manual. The 375 appears to be working in its entirety however I continue to get this message. Stien has provided a new config module which we replaced...same error. We have sent screen shots that shows green checks in the settings. The wires and pin outs appear correct and are confirmed by the green checks in configuration mode. Before I pull it and send it back I was wondering if anyone else has plowed this ground already. If so what did you do to clear the message?
 
Most units will display that if they can't get a GPS signal after some length of time.
 
The maintenance manual is every specific about this error code....it has to do with the config module (replace it, check settings, etc.) but other than that there is no guidance. I replaced mine (via a hot spare from Stein) and got the same error.
 
Bart,

Does the Diagnostics, XPDR, Warnings page show a CFG Module error like this?

Diagnostics_XPDR_Warnings.png

If there is a red X by CFG Module, this could also be caused by configuration module wiring.

Steve
 
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The maintenance manual is every specific about this error code....it has to do with the config module (replace it, check settings, etc.) but other than that there is no guidance. I replaced mine (via a hot spare from Stein) and got the same error.

My GNC 355 displayed that at initial power up. After bringing it outside, and getting a good lock on the satellites, the message cleared, and has not appeared again. As Walt said, likely my case was likely tied to not getting a a satellite lock.
 
why yes it does exactly

Steve - Can you reference what I should be looking at with regard to the wiring? i.e. a wiring diagram? Are you talking about the 3 wires actually going into the config module chip? Maybe that's the issue but if I could reference where they should be attached I could verify that...my harness was built by Stien and it was flawless but this has been ran enduring message that just won't clear after all of phase one flying.




Bart,

Does the Diagnostics, XPDR, Warnings page show a CFG Module error like this?

View attachment 8673

This could also be caused by configuration module wiring.

Steve
 
Steve - Can you reference what I should be looking at with regard to the wiring? i.e. a wiring diagram? Are you talking about the 3 wires actually going into the config module chip? Maybe that's the issue but if I could reference where they should be attached I could verify that...my harness was built by Stien and it was flawless but this has been ran enduring message that just won't clear after all of phase one flying.

Bart,

Both the GNX 375 installation manual and the G3X Touch Rev. AM Installation manual (page 27-37) provide the wiring diagram for the configuration module mounted inside the backshell of the GNX 375 connector. There are 4 wires going from the GNX 375 P3751 connector to the small connector on the config module.

GNX375ConfigModuleWiring.png

One thing to keep in mind is that once you fix this problem and your GNX 375 finally communicates with its config module (assuming it never has), the System ID of the unit will change to match the config module, and you will have to ask Garmin to edit the System ID you may have entered in FlyGarmin to match the new System ID.

Steve
 
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Steve - thanks for the input. Since I still have Stien’s hot spare config module installed- I wonder if my system ID has already changed. I’ll start field stripping that unit tonight and see what the wiring looks like one last time. Prior to this it was just LRU to LRU replacement of the config module chip. I did check the pin outs and checked the wires when I swapped the config module but it didn't occur to me to see if there was a broken pin or a loose connection. The learning curve on removing the chip was time consuming...should be faster on the second go. Garmin did offer to send a replacement unit but I had to provide credit card for the full price of unit until they revived the defective unit back at home plate. I guess that's fair but seems a little unfriendly. I'll probably go that route if I can't find a problem with the wiring.
 
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