New DFC90 disconnects in Cruise

My Cirrus Serice Center installed the complete "Panel Overmake" package into my 2006 SR22-G2 this June. Overhauied PFD/MFD, DFC90, Flap Wire, all the latest software

For the first 40 hours it worked nicely and was reliable.

Now, two days ago on an IFR flight through Germany in FL90 after the first 45 minutes the A/P disconnected itself without a warning. No other message or error message, only: "Autopilot Disconnected", of course with the beeps that come with it.

Ten minutes later this happened again, then the next time after 3 minutes, 2 minutes ... in the end it only worked in uncoupled FD mode.

On a second 90 minute flight on the same day it worked again, did not disconnect.

I let the Cirrus service Center measure the servos and they said that the  3.5 volts in the roll servos are "okay" (which i doubt). They said that they cannot do more than that and that I should "observe" the AP ... (they did not say if i should observe it it in VMC or IMC !)

On the flight home it happened again: Disconnected in IMC three times in sequence, no other error message than "Autopilot Disconnected".

After hand flying for 10 minutes I switched it on again and it worked for the remainder of the flight.

I also got an eMail from my Service Center in the UK that I should check the aileron trim tab setting and that this could be the reason especially in strong crosswinds. I did have crosswind up to 35 knots at altitude but i have a hard time believing this can be the reason.

The DFC is under warranty but nobody has really told me what to do until now.

Any Ideas, information, tips?




Edited by GYORC - 03 Oct 2013 at 3:48pm

Hi, thanks for the quick answer
- the servos were tested by the Cirrus Service Center and I think they measured 3.5 Volts at the Roll Servo. They said that that's okay (..). They also measured the pitch servo and said it's ok.
- It has nothing to do with the tray I think. We took it out and put it back in again (as Aaron recommened)... and it also worked perfectly for the first 40 hours
- The trim tab idea came from the Cirrus SC in the UK that has installed the autopilot (RGV, Alec Vincent). So i don't have to test that? The TRACKING PERFORMANCE IS PERFECT!
- Yes, the normal disconnect tone in the headset and the yellow message on the PFD "Autopilot Disconnected"

I had a "Servo Limit" message maybe twice for a second or two in the last two weeks, but really only a second or so


Edited by GYORC - 03 Oct 2013 at 10:49am

I'll go check on the roll servo installation and warranty question with Customer Service guys.  I suspect they'll send you a direct note in response but let me go check with them now.

Have you gotten a call/email from Avidyne Customer Service to resolve your question?

BTW, why does Avidyne not let its partners read out the DFC90 error log? I suppose the device will store the reason for such a disconnect in a non volatile memory area which can be read out.

Customer service has not contacted me so far.