Error codes on 1992 Volkswagen Jetta

How do I get the error codes for a 1992 Jetta

Asked by for the 1992 Volkswagen Jetta
you car is not obd2 compliant. the best place for info and to buy diag testers for vw or audi is trust me, its as good as factory stuff.
To some guy: will that also work on 1999 Audi's?