MCU failure

The MCU failed in our SR22 on Sunday over Santa Barbara. While I was able to maintain communication on the established frequency using the #1 Garmin, I was surprised to see the screen go blank. Also, I could not disengage the autopilot without pulling the circuit breaker. I would like to know if both of these should have been expected. Incidentally, when we were bringing the plane home last August, we fried a starter in Montana and the mechanic there said we would be replacing the light weight starter someday. I suspect we just lost another one but the diagnostic work has not been completed yet.

Gary, how many hours on your SR22?


Hi Gary,
I was in the other Cirrus in the runup. I’m curious to see what Chris says locked the autopilot and NAV1 screen. Perhaps they were spiked with power. Did you try recycling Avionics master power in air or on ground?

Loosing the essential bus nav/map functions is bad news. Did the gyros stay alive?

If there is anything I can do to help, since I work near the airport, let me know. I would like to have given you a ride last Sunday, but I called you back about 2 seconds late (you’d shutdown) and I had to run to Santa Maria first.


In reply to:

The MCU failed in our SR22 on Sunday over Santa Barbara.

That explains what we thought was the Aurora Borealis over our house!

Seriously, this is a troubling failure. To lose (one “o,” guys) your #1 Garmin’s display and have your Autopilot freeze up is pretty odd. If this had been in IMC you could have been in deep Bandini. Did you lose the Sandel? Instruments?

I know the guys at Stratman and they’re very thorough and sharp, so I expect they’ll get to the bottom of this with Cirrus’ help. I live and work less than two miles from the airport, so if I can provide any assistance please email me and let me know.

200 hours on N84PW SR 22

I didn’t try recycling the avionics master power. The gyros did stay alive. I’m just now learning how many others have had similar problems. I understand Cirrus doesn’t cover replacing the light weight starter with the Continental starter. If I go that route, will Cirrus pay the incremental cost for the heavier starter? Thanks for the offer for a ride, it was a long drive in Sun. pm traffic.

My understanding is Cirrus will not cover labor to install non-warranty parts… so installing an Energizer starter even in the case of a failed Light Weight will still cost you (Stratman is about 1 hr labor and $360). You get no warranty help.

Interestingly, Chris has already replaced 1 starter/adapter and 3 MCU that have failed.

Did you have three passengers or four? Curious if it would have worked anyway. Maybe I can give you a lift back up here when it’s ready to go.



You should join COPA. You will find access to the members forum and Response sections Worth the small price of admission many times over