I think your aircraft has a problem and I suggest having an avionics shop look at it.
A few Notes:
Cirrus customer support people got pretty irritated with me when I switched radios to debug a similar problem, though in my case it was the radio that was bad. I had previously been instructed by a technician on how to swap the radios and I’ve handled, taken apart, fixed, designed, built, etc. expensive electronics for most of my professional life. But that didn’t matter to the Cirrus – I’m an owner so I must fly the plane, but not be too involved in its repair.
The Cirrus customer support person I’ve dealt with knows almost nothing about avionics and can’t judge whether something is appropriate for a pilot to do. They are nice people, but don’t expect them to be rational on the topic of pilots who are interested in debugging avionics problems, even if the problems have stumped the shops (with Cirrus’s help) for several months.
There is setup information in the Garmins specific to its position in the stack. You can read the Garmin installation manuals on the web, in PDF, if you are interested in what all the setup info is about. Or you can swap the radios back.
While companys like Sandel, Arnav, and Garmin are comfortable with telling you, the pilot/owner, how to fiddle with maintenance modes of their products, that doesn’t mean that Cirrus will be comfortable.
Knowing the maintenance modes of the avionics can be useful in general. I found an avionics guy who had read the wrong info on how to setup the Garmins and mis-set mine. (This contradicts Cirrus’s position that owners are incompetent and avionics techs are all-knowing in this area.)
Cirrus has so far not released the AWD (Airplane Wiring Diagram) for the SR22, though Ian Bentley said it would happen this fall. In the meantime, they are reluctant to share the schematics they do have. And they refused to share these diagrams with me, an owner. Fortunately, the shop shared them with me, which allowed me to debug a problem that the shop hadn’t been able to in two months. Cirrus also refused to send me or my shop the Cirrus-specific setup information for the SR22 avionics, leading me and my shop to guess (which isn’t hard).
Probably more information than you were looking for, but there you go.
Good luck and step carefully around this issue with Cirrus customer support.
I have one Garmin radio that is markedly less sensitive–I am unable to hear ATIS from a distance, while the squelch is broken on the other radio, and receiving perfectly.
I switched the two radios in the racks, so I have determined it is an antenna/install issue, not the radio itself.
The less sensitive install is certainly adequate once I’m closer, just not as sensitive. Any similar experiences? Is this a ground plane issue related to antenna location? I’m inclined to live with it, but I am kind of compulsive, and it is under warranty . . . opinions?