Why wont the engine start

Hello Vicky,

From what I can tell, the factory stereo is integrated into your car in such a way that you can't just replace the stereo in a straight swap. There are adapters needed to take care of several car data functions that your original stereo performs. These functions, if they get messed up, like having missing parts in the system, can cause your car not to start. It likely isn't even cranking the engine for example. This is a known problem. There are workarounds, but they don't involve getting a code, they involve installing an adapter that you will have to buy. You can reinstall your old stereo and everything should be fine until you get the parts you need to make this work. Here are a few links that will help. Crutchfield apparently sells the adapter that can solve many of the problems.

Crutchfield on upgrading the Pontiac G6 Stereo: https://www.crutchfield.com/S-SAuce5DrBE...

Pontiac G6 Owners Club Forum: https://www.g6ownersclub.com/threads/car...

Pontiac G6 Owners Club Forum: https://www.g6ownersclub.com/threads/car...

Mobile Edge Online regarding a dashboard part (seems pretty old): https://www.mobileedgeonline.com/special...