You didn'y say which model of car that you have. You gave the age, engine size, trim level and gearbox but is a a Panda, 500, Punto, etc? Knowing that may lead to someone with the same car telling you if was available on not back then.
You can not switch it off. If you learn that you should have it and don't (also try your owner's manual) and it's not working, it may be a bad fuse or lamp that needs changing.