When steering effort is affected both directions equally, that is typically caused by a worn power steering pump. You didn't list the mileage so I can't make any judgements related to that. Your car uses the "ZF"-style pump which is known for worn vanes and the resulting low pressure, but the symptoms include the power assist usually comes back when you raise engine speed.
Most manufacturers have seen fit to add an unnecessary computer to the steering systems, so that adds another series of potential problems. Your mechanic will have to use a scanner to view live data to see if there's an electrical problem causing loss of power assist.
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Thursday, March 19th, 2015 AT 9:05 PM