I'm the happy owner of a 2015 2500HD 6.0 Flex Fuel Double Cab.
When I fill the tank, I get in and turn the key, pause, then bump the key to start.
It will turn the starter longer than needed (3 or 4 seconds) then let go.
The motor usually fires, but once in a while she'll stall.
Mind you, this only happens at the pump. I have not had this issue any other time.
Thanks in advance for your thoughts and opinions!