Lane A Fault Light On Steady 912iS

[Amadeus]

Beautiful day today to go fly. Did preflight, sart-up, oil warmed up to above 120 on taxi to run-up area then throttled to 4,000RPM and switched off Lane A - all good - then switched back on and the light remained illuminated. After cycling Lane A again the light still remained illuminated.

This being the first time for this to occur I was curious if the engine would just shut down if I flipped off Lane B with Lane A light on. Engine continued running but running slightly rough. Flipped Lane B on again and the Lane B fault light went off while Lane A remained lit.

I sat and pondered a minute since with both lanes flipped on the engine runs smoothly and coolant temp, oil temp and oil pressure all remained in a good place. It was then that I decided I would use the engine sensors to help me narrow things down.

When I flipped off Lane B the EGT for cylinder 3 dropped off. Flip on Lane B and the engine smooths out and EGT for cylinder 3 returns to normal.

I pulled into the hangar and let the engine cool down as I removed the top cowling and went to lunch. Came back, pulled the top spark plug (Lane A is top plugs) and it appeared to be clean and functional. All spark plugs were replaced just 3 flight hours ago during annual condition inspection. Of note, I replaced with NGK spark plugs instead of the Rotax plugs. Even though the plug appeared to be fine I replaced the plug with another NGK (16 NGK plugs came with the RV-12iS when I purchased) off the shelf. Started up only to discover same results as from the previous run-up.

Any suggestions of where to begin troubleshooting?

[jrtens]

I think Lane A powers ignition coils 1 and 3 which power the bottom plugs per the diagram on page 281 of the heavy MM.

[jrtens]

One possibility is that during the inspection the ignition cable was slightly dislodged from the spark plug connector. Make sure that cable is firmly lodged in the connector.

Also, what does your engine fault page say?

[Amadeus]

Originally Posted by jrtens

I think Lane A powers ignition coils 1 and 3 which power the bottom plugs per the diagram on page 281 of the heavy MM.

I think you're right...

oops

Thank you!

[Amadeus]

Originally Posted by jrtens

One possibility is that during the inspection the ignition cable was slightly dislodged from the spark plug connector. Make sure that cable is firmly lodged in the connector.

I will check the cable/connector AND spark plug when I get back over to the hangar.

Thank you!

[Amadeus]

Originally Posted by jrtens

Also, what does your engine fault page say?

"Engine fault page".....Is that something the G3X would have?

[jrtens]

Yes. You have to go to a submenu to get it.

[mburch]

Originally Posted by Amadeus

"Engine fault page".....Is that something the G3X would have?

Originally Posted by jrtens

Yes. You have to go to a submenu to get it.

If you have a G3X Touch system, you can view FADEC fault information from a variety of pages:

• From the Engine page option menu
• From the Engine Setup page in the main menu
• From the System Diagnostics page in the Diagnostics menu
• From the System Information page in configuration mode

[G JWTP]

Have a look at Rian Johnson of Vans explaining it.

https://www.youtube.com/watch?v=lNHsB9Y1xuw


John.

[csmith3603]

Howdy there;

Yep both Garman & Dynon have a Fault page for Dianostics if it logged!

Could be the wires.....

Anybody know of were to borrow a Rotax B.U.D.S dongle if the above fault
page is cleared to get at the history log,, What a monopoly!


Charles