There was a Q&A in Journal #1. Turning to include the direction applies to BMG/CMG.
"C3.2 & D1.81-.2, D8.5 Can a Gun fire in its own hex (i.e., is its own hex considered in its CA)? Do the same principles apply to BMG/CMG?
A. Yes; except during the MPh if the hex is entered from outside the CA, when, even if the moving target now expends MP for some other purpose (e.g., firing sD or stopping and unloading Passengers), the Gun would still have to turn its CA to include the direction from which the hex was entered, or if the bow-mounted weapon of an Immobile vehicle (D8.5). Yes. [J1]"
So I'd say that unless the berserk unit entered the AFV's location from the TCA, the AFV would have to change CA so the TCA includes the hexside crossed.