53 plate vrs steering problem

having a problem with my vrs dreaded steering problem 

anyway past few months the steering light would come on, didnt seem to effect the steering, if i restarted the car the light would go out and would stay out for a good period a month or two 

then it started happening every week, then it started happening everyday  

now the light is permantly on, the steering goes from heavy to light, normaly heavyer at lower speeds) had the car plugged in and he said that its come up with a error to do with the control module? 

the control module is built into the pas pump, there for would it need a new pump? or anything i can check, 

ive searched everywhere and i cant find anything on the control module so i asked here

thank you matty