The oil level in the power steering pump is low.

Check and add power steering fluid, as necessary. Refer to Checking and Adding Power Steering Fluid .

The belt on the power steering pump is loose.

Inspect the drive belt for wear. Refer to Drive Belt Tensioner Diagnosis in Engine Mechanical.

The pump pressure is insufficient.

Test the power steering system and repair as necessary. Refer to Power Steering System Test .

A gear relief valve is faulty.

Replace the gear relief valve. Refer to Steering Gear Check Valve Replacement - Off Vehicle .

The flow control valve is faulty.

Replace the control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle .