I honestly don't understand exactly how our system works, since it's 'valvetronic'. But yes, there's obviously a computer operated valve somewhere that varies assist. If your inner belt is tight (drives both the water and P/S pumps), and pump doesn't 'whine' while turning stationary, then it can be the valve, rack, or an electronic gremlin. To eliminate the electronic part, I'd disconnect the battery and see what happens after that. If it doesn't improve, you'll have no choice but to take it in; it's going to be something mechanical. Probably the valve, but could be the rack too. Good luck man, and cover your seats, knob, carpet, and steering wheel
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