Abstract: A control system 14 and method for preventing exhaust gases from entering an intake manifold 26 of an engine 21 after engine shutdown is provided. The engine 12 includes a valve controlling air flow into the intake manifold 26. The method includes determining when the engine 12 has been shutdown. The method further includes opening the valve for a predetermined amount of time after the engine shutdown to allow air at ambient atmospheric pressure to communicate with the intake manifold 26. Thus, a relatively high air pressure in an intake manifold 26 prevents exhaust gases from migrating into the intake manifold 26 which reduces a subsequent engine crank period.

Abstract: A method for determining an operational state of a vehicle starter motor coupled to vehicle battery includes the steps of detecting a vehicle battery voltage, deriving an average vehicle battery voltage, and inferring the operational state of the starter motor based at least in part on a difference between the detected vehicle battery voltage and the average vehicle battery voltage.

Abstract: A method for preventing reverse running of an internal combustion engine includes determining the operational state of the vehicle starter motor, determining whether a stall or imminent stall condition exists, and suspending operation of the engine based on the stall or imminent stall condition.