An auto-stop/start vehicle may enable a stop/start strategy for starting and stopping the vehicle engine during a drive cycle. This may occur, for example, when the vehicle stops at traffic signals, cross-walks, stop signs, and the like. The engine is shut down if no power is required (e.g., while waiting at a traffic light). As soon as power is requested, the engine is automatically restarted. By avoiding unnecessary engine idling, the vehicle's fuel economy will be improved. For this reason, it is desirable to use the engine shutdown function as much as possible when engine auto-stop conditions are satisfied.
In many approaches, a presence detection system determines the presence of a driver as a necessary condition prior to initiating an engine auto-stop. In still other approaches, engine auto-start is initiated upon detection of a driver exiting the vehicle.