How to retrieve current radio code for my 2004 chevy aveo?

My vehicle is a 2004 Chevy Aveo LS hatchback. My radio did same thing end of last year. Try these codes below and instructions. Mine was 2152.

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

1. Turn the ignition to ACC or On Mode.
2. Turn the radio on look at disolay to see if AF or COdE appears on screen. If AF (go to step 3) and if COdE (go to step 4)
3.Enter AF Code (Usually Zipcode from dealership purchased from)by pushing the preset pushbuttons. COdE will then flash on the display.
4.Enter one of the codes from above if it flashes 3 times then it's the correct code if Err appears then with in a few sec's then it is incorrect move to next code.

****** Please Note ******

If incorrect AF code (Dealer Zipcode unless in Asia if in Asia push 5 and follow directions on screen) is entered an incorrect frequency level may be chosen and the radio reception may be affected if this occurs reset the audio system by removing and reinstalling the audio fuse then repeat steps 1 through 4. Hopefully this will work. Good Luck.

Here's an easier way. Purchase a 9 volt battery powered radio / computer MEMORY RETAINER. Plug into your cigarette lighter/power socket SECURELY. AFTER replaceing the battery, remove 9 volt poer feed, and BINGO. Radio stations memory, clock will all RETAIN. their memory. Hope this helps