You are going to have to get a scanner that reads (B)body codes and U codes for data faults first, you will find either communication problems with module/s or a VIN mismatch
A community for Pontiac G8 owners and enthusiasts, for all the information on your Pontiac G8 sedan, G8 GT, G8 V6, and G8 GXP. Discuss performance, tech, engine specs, body kits and more!