Powersteering failure diagnose sudden powersteering failure on 2003 Lincoln Aviator

Check your power steering fluid level. If the dash lights, warnings, flicker on momentarily then your Surpetine belt is slipping and the tensioner could be weak. You need to indicate if this is at idle or what speed. Also if your 4x4 is on it will not turn sharply at low speeds. Its easy to turn on the 4x4 instead of the other control.

Check your power steering fluid level, then check for any leaks. also a worn belt will do it.