One of these number is the code, I found them at a different site - hope you didn't pay the $105 my dealer was asking for. #3241 worked for me!
GM Chey Aveo Radio:
1156, 1165, 1325, 2145, 2151, 2152,
2253, 2346, 2453, 2654, 3116, 3221,
3241, 3251, 3265, 3346, 3451, 3462,
4136, 4314, 4316, 4362, 4513, 4524,
4853, 5241, 5253, 5312, 5436, 5445,
5624, 5813, 6361, 6451, 6645, 8253
GM Chey Aveo Radio:
1156, 1165, 1325, 2145, 2151, 2152,
2253, 2346, 2453, 2654, 3116, 3221,
3241, 3251, 3265, 3346, 3451, 3462,
4136, 4314, 4316, 4362, 4513, 4524,
4853, 5241, 5253, 5312, 5436, 5445,
5624, 5813, 6361, 6451, 6645, 8253