"Show me /explain how would you check that the power assisted steering is working before starting a journey"

If steering becomes heavy the system may not be working properly. After starting the engine two simple checks can be made. Gentle pressure on the steering wheel should result in a slight but noticeable movement as the system begins to operate. Or, turn the steering wheel as you move off, you will get an immediate indication that the power assistance is working

Information suppiled by the DSA.