ignition coil and Garmin GEA24B failure
Thought I'd share an issue and resolution from a recent incident
Rotax 915is, ~500 hours.
Lane A solid light came on during a routine flight. Rough running symptoms for about 2 seconds before the light. Landed nearest airfield
FADEC page showed ignition/injector driver error and Cylinder 2 EGT fault
Had to leave the plane overnight - no time for in-depth diagnostic
Next day, most engine instruments were x'd out on G3X EFIS: Manifold pressure, RPM, oil pressure, oil temp, coolant temp, EGTs, fuel flow and FADEC data all unavailable
Engine ran normally on lane B, very rough on lane A
Diagnosed the cylinder 3 was not firing on bottom plug. Inspection and swap of plug, boot, and wires yielded no change.
After lots of dead-ends, finally replaced the coil, which eliminated the rough-running problem. The failed coil had tight connections with both plug wires. This wasn't the first route of thinking as normally 2 cylinders would fail from a bad coil, but only cyl 3 was failing.
Engine instruments still not working. Replaced the Garmin GEA24B with a loaner, all instruments came back.
This is the second incident I'm aware of where a failed coil and failed GEA24B occurred together. Not sure how it's related, but I don't think it's a coincidence. This engine has the old-style connectors on the coil.
