1997 Volkswagen Polo fault code

when I turn the key a code comes on the mileage counter it say in 02 what does this mean and what do I do to get rid of it please .I can not see any problems with the car it drives great and does everything it should but as its a old 1997 polo the code could have been there for years I don't know as I have only just bought it has a ne battery starter motor and new starter motor bush and has very low mileage and has been serviced aswell with all the new bits changed that needed changing.but its just that code ?

many thanks paul