We operate a sub-fleet of 9 aircraft with dual 430’s, some aircraft crossfill between two is not a problem other’s it does not work, when one or the other is swapped out it is always a software bug or user set up. Our sparkies seem to have inconsistent results in sorting the problem.
One cause was differing database dates between units on installation which caused a the system to note a difference and hence not accept the crossfill, this is how it was relayed to me from the big spark himself.
My advice speak to a Garmin rep or quality dealer.
