My daughter has an Aygo and the power steering light comes on intermittently, and she loses the power steering. The car went into a garage last week but ( of course) the light wouldn't come on for them so nothing got resolved. Today she has just rung to say it came on immediately upon driving and has stayed on. I'm going to suggest she takes it to a garage I use, but just wondered if there were any suggestions as to cause and possible cost to fix?