2004 Suzuki Forenza SSPS Light

Speed Sensitive Power Steering System Description
The speed sensitive power steering (SSPS) system varies the driver effort required to steer as the vehicle speed changes. At low speeds, the system provides maximum power assist for easy turning and parking maneuvers. At higher speeds, the steering power is reduced to provide the driver with firmer steering and directional stability. The SSPS system accomplishes this by reducing the amount of power steering fluid flow from the power steering pump to the power steering gear as the vehicle speed increases. When the vehicle is stationary, the SSPS system provides maximum fluid flow to the steering gear. As the vehicle speed increases, the fluid flow to the steering gear is decreased.
Control Module
The SSPS control module processes the vehicle speed information from the engine control module (ECM) and uses the steering wheel rotation sensor to provide a control signal to the electronic variable orifice (EVO) actuator located on the power steering pump.

I would suspect a bad/faulty sensor sending a wrong signal. Have the vehicle plugged into a diagnostic computer to see if there are any fault codes showing !