For 1990-2009 cars

Problem | Action
--- | ---
The fluid level in the pump is low. | Add power steering fluid, if needed. Refer to Checking and Adding Power Steering Fluid .
The pump belt slips. | Refer to Drive Belt Replacement in Engine Mechanical - 2.4L or Drive Belt Replacement in Engine Mechanical - 3.1L.
Internal leakage in the steering gear or the pump is high. | Refer to Power Steering System Test .
The flow control valve sticks closed. | Refer to Power Steering System Test .