From my internet wanderings,this appears to be an engine management light,so the simple answer would be to take it to a dealer and get the fault code read,and go from there.
Its not a light, its a message on the dashboard screen.
@username123, The vehicle was serviced quite recently but not by an opel dealer.I used to drive a passat and these messages could be deleted or reset by a couple of methods. The passat work arounds are easily available on the net but I just cant find one for the Insignia.
Hope this clarifies
westgolf