Hi,
Because of personal reasons I didn't fly for +/- 6 months and my airplane was in a dry hangar all the time. A few weeks back I pulled the plane out of the hangar for a flight but the efis displays a big red cross over the transponder (trig transponder with mgl interface) and rotating the barometer knob doesn't work, it seems to adjust the pressure setting but it's reset within a few milliseconds. The last flight (july 2024) everything worked fine.
I connected my laptop with a can interface to the can bus and tried to control the transponder directly, that seemed to work so the transponder looks ok. I made a dump of the can traffic and sent that to MGL/Rainier and got a quick response that he noticed 2 weird things in the dump:
- the ibox is sending 7FF messages thinking that it's a standby ibox
- there are 440 messages sent which indicate the efis is in "MX1 compatible mode" and therefor not expecting an ibox at all.
Now this explains the behvior of the transponder that is not working and baro being reset instantly, but I can't find the root cause.
- The D3 pin on the iBOX is floating, it's not grounded (unless internally shorted, but the hangar is very dry, there is no debris or whatsoever in the panel)
- I can't find any "MX1 compatible" setting in my G3 challenger, I think I went multiple time over every (sub)menu item twice to find it.
On the efis in the left corner there is a green square with a P in it, indicating a primary iBOX (I think). I configured the system to single ibox, but also tried setting 2 ibox'es.
I tried many things and spent many hours debugging this problem, from the can bus to checking all wires, pins, grounds, settings, etc. Untill it's fixed I can't fly the airplane and really need to.
Is there perhaps anyone with (good) suggestions ? I am also thinking of doing factory resets, but Im afraid to loose my settings. I am not sure if the setup.dat export contains every setting like the menu-settings, AP corrections, screen customizations, etc.
Any help is very much appreciated.
Thank you.
baro and transponder stopped working
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Re: baro and transponder stopped working
Some findings from a weekend debugging/troubleshooting:
- when power from the ibox (v2) removed I can change the baro pressure on the iefis, but it jumps back immediately when the ibox is powered on.
- removing all the can connectors from the ibox doesn't make a difference
- the 440 messages seem to come from the V16 radio, they disappear when I remove the V16 from the CAN. But the problem remains.
- all devices requiring active communication seem to have stopped working, only passive-communication devices appear to function normal. So this could very well indicate a iBOX behaving as a standby box. What has stopped working are trig-transponder-interface and the ap-servo's. What does work are the ahrs for example.
I don't see anything in the CAN protocol doc's on primary/ standby but found in a CAN dump from last year also 7FF messages, and back then this issue didn't exist.
- when power from the ibox (v2) removed I can change the baro pressure on the iefis, but it jumps back immediately when the ibox is powered on.
- removing all the can connectors from the ibox doesn't make a difference
- the 440 messages seem to come from the V16 radio, they disappear when I remove the V16 from the CAN. But the problem remains.
- all devices requiring active communication seem to have stopped working, only passive-communication devices appear to function normal. So this could very well indicate a iBOX behaving as a standby box. What has stopped working are trig-transponder-interface and the ap-servo's. What does work are the ahrs for example.
I don't see anything in the CAN protocol doc's on primary/ standby but found in a CAN dump from last year also 7FF messages, and back then this issue didn't exist.