A problematic hydraulic system.

Diagnose the hydraulic system. Refer to Power Steering System Test Procedure.

The power steering fluid level is low.

Add power steering fluid. Refer to Checking and Adding Power Steering Fluid .

The power steering gear valve is sticking.

Flush the power steering system. Refer to Flushing the Power Steering System. Bleed the power steering system. Refer to Power Steering System Bleeding .

The power steering pump pressure is insufficient.

Refer to Power Steering System Test Procedure. Refer to Power Steering Pump Replacement , or Power Steering Pump Replacement .