Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
If the unlock codes are old, then you might not find them usable with new maps. But if the maps are not new, just the Garmin you are loading them on, then that might be workable.
The codes have to match the maps rather than the Garmin, you see.
Tell me more about the challenge you need help with. Thanks.