As you haven't provided any information to help troubleshoot, try reading through this thread that discusses error 6. Cheers.
--------------------- ZZZING 2000 Z3 2.3 Oxford Green Beige/Black Sharked, StrongStrut , Whalen Knob, LeatherZ, M upper shock mounts, Koni Sport Shocks, SSR Competition Wheels, HIR bulbs, Oxford Green Hardtop