It shuts the engine off kind of randomly. Often after I get off the freeway having driven 20 minutes or more it doesn't shut the engine down at a stoplight. Other times, driving around town partly warmed up, it shuts off at every light. Other times not, even fully warmed up. This is without the heater, or the seat heater, or the A/C, or the lights, and I'm coming to a full stop with no creeping so I see no obvious reason that it shouldn't be working. It seems like the one time it should always work is after some highway driving. It makes me wonder if my battery is going south because this is new behavior. Do these trucks do some weird **** with battery management where alternately charge and allow discharge of the battery during extended driving? What could be going on here?