Hi everyone

repaired a A4 B8 2009 model (only passenger doors, fender & wheel were damaged), got the car with no battery. so stuck another battery in and sound everything was great. after about 2 weeks car was done but battery was dead. so i got a new one from Audi. but when i connected it, no sound from mmi unit had car @Audi hooked up to their VAS bt their laptop cant read the radio( error comes back - radio not reachable ) anybody out there that can help? also PDC not working since battery change

any info welcome
thanx