My car apparently has power 'assisted' steering which is 'sensed' by the speed of the car. Works fine on the hwy at 40mph+, but no power steering available at low mph, u-turns, parking, etc.. I'm told that there is a 'valve' (Solenoid Valve?) inside the power steering gear box that is the mostly likely culprit. Fluid level is fine and there are no leaks.
No power to steering, and power steering fluid is not the problem on 2004 Mercedes-Benz E500