The GNS 530 of the C172 has a small and a large left knob for entering COM and NAV Freqs.
The small left knob can be pushed, it’s marked „PUSH C/V“
The GNS 530 manual says: „*Press this knob momentarily to toggle the tuning *
cursor between the COM and VLOC frequency fields“.
But this COM / VLOC toggling doesn‘t work, pushing the knob has no effect.
I further testet the G1000 in the C172.
Here is switching from N1 to N2 and COM 1 to COM 2 by pushing the middle knob not possible.
Swapping from standby to active is possible with both NAV and COM.
Are you using any mods for G1000 or GNS530?
no, no mods, never used any.
Issue solved, I can’t believe what the solution is.
It’s the annoying „All Assistant“ function, introduced with one of the latest updates. As soon as you move your mouse over any button or knob an explanatory text field pops up. Just these popups block the original control function, here it was the COM / VLOC toggle button.
I’m sorry, but it’s simply stupid. The actual button function is blocked due to the explanations to this button.
After disabling „LOCKED“ (under ACCESSIBILITY) to „LEGACY“ to spook is gone.
Thank you so much for this, was bugging me for so long and could not figure it out for the life of me. Crazy to think that the feature to help explain buttons just disables a super important button🤣. Its all good hopefully they fix it for everyone but thank you so much for posting this solution was fking killing me
Hello I have the all assists off. Can’t push the Vloc button (push C/V) to swap between Com and Nav. I am using a PA44 Seminole from Carenado. GNS 530.
Go to General Options, click Accessibility (on the left bar) and then change Cockpit Interaction System from “Lock” to “Legacy”.
Solved it for me, many thanks!!!
thanks mate. someone who actually stated EXACTLY which of the 100s of settings it was. (works g8).
Thanks! Wow! I was really looking for a fix for this for hours. But now I have no justification to my wife to buy GNS 430/530 hardware
Thank you.
I know it’s an old thread but I had this issue today and wasn’t sure what the problem was. Thank you for the solution 
@StrohSchema7980 answer is correct. The directions to the option are: General Options > Accessibility and under the User Interface section Cockpit Interaction System should be set to “LEGACY”
I’m guessing this is a bug that has come back because I have not seen this probem before AAU3
Actually…
The following options are all in the General Options > Accessibility and look under the User Interface section (The second one down from the top).
Definitely feel red faced over this one. It is possible to switch between COM and VLOC on the GNS 530/430, while when Cockpit Interaction System option is set to LOCK . If you are having problems working out what to do turn Instrument Description Tooltips to INSTANT or DELAYED . A mouse icon of a hand pointing up and right tells you the control is just a toggle and is operated by left clicking the control. More complex controls have a flat hand mouse icon. This implies the control needs more complex manipulation. If you left click and hold you will see a tool tip telling you how to use the control. In the case of the GNS PUSH C/V control. There is a tool tip that says if you right click the control is is the equivalent of pushing the end of the control and that it will “Select between COM and VLOC”.
My feeble excuse for failing to note this is that I thought I had tried right clicking the control and that it had no effect (I had failed to read the tooltip properly) 
sPK
