Hi steering assist malfunction warning light has come on my Ford Focus 2011 ,usually happens a few times a month and the car is almost impossible to steer ,if you turn the car off and then on the problem sorts it self out ,I have taken it to a ford garage and they say they could not diagnose a fault but if it happens again the steering rack and pscm will need to be replaced ,is this right ?can The module be changed without changing the rack ?i woul be grateful if any has any advice .I changed the battery but that didn’t work