Hi guyz i am back from my trip to another neighbouring country as it was a long journey i drove 2500 miles and on the way back it was sandstorm as the road was passing through a desert huh and i have got this error which says on dashboard screen as "required maintainance" and other one says Check PCS < this i could say is of the radar detector in front of the ultra luxury package as it got dirty with sand and cleaning it still i have the error

and i really want to know what does required maintainance mean

please help