what to look for with code u0401 on 16 focus st

Question

was in traffic idling and engine fault popped up on my info screen and the engine starting misfiring, sounded as it was with popping in exhaust but could not feel it. it had no throttle response and would start to stall when i would give it throttle. i turned it off and back on but not started and the hill assist fault and key not detected popped up on the info screen,i turned it off again and then started it and it ran fine. no check engine light but when i got home i used my matco maxme diagnostic scanner and found code u0401 in the abs, ocsm occupant classification system module) and rcm (restraint control module), that was the first and only time it has done this. what do I need to look for because the freeze frame has nothing recorded and everything seems to be working ok.