applied vehicle speed below a maximum allowed value engine temperature reasonably close to its operating norm and minimum air pressure levels available the state shifts to an engine off state 404 armed for a rapid restart of the engine 70 initially the climate and electrical loads already active are carried air pressure to operate power assist for the brakes and steering is supplied to continue operation of those accessories using air pressure as an alternative prime mover for as long as the engine is off in other words were the driver stopped for traffic he or she would not feel a loss of steering boost nor would the air brakes discontinue operation deterioration in the voltage state or loss of air pressure would represent a load condition violation and the state would change depending upon the character of the violation a deteriorating electrical state could be dealt with by shedding the electrical loads as represented by state 406 state 406 represents various electrical loads having been shed possibly as the result of a progressive series of transitions feeding back on state 406 alternatively a load condition violation if it persists or exceeds other thresholds may be dealt with by cranking the engine for a restart either hydraulically state 410 for an electrical load condition violation or electrically state 408 for a pressure condition violation it is possible that the load condition violation could be removed by connection of the vehicle to an external air or power source or operation of an auxiliary power unit if available accordingly a transition from state 406 back to state 404 is shown electrical and cab climate control related loads.