There will be a test Buying a NEW SCT you will receive 3 tunes for your vehicle, and once you install them in the vehicle there are two open spots left in the SCT DEVICE for use on another vehicle BUT you will need new tunes for the new vehicle. A new device will have the ability to be VIN locked 3 times. A VIN lock gets consumed the first time you use the device to flash a vehicle with a file other than stock. You can then flash that same vehicle an unlimited amount of times with any custom tune or back to stock. The device will remain VIN locked as long as a custom tune is flashed or "loaded" into the vehicle. It will be able to be UNLOCKED once you return the vehicle to stock. This can be viewed under device options. If the Device status is STOCK, its UNLOCKED, if its aftermarket its VIN locked. You can also view how many vin locks are available under device info it will list â€œchanges leftâ€. If that gets down to 0 SCT needs to unlock it. Buying a USED SCT, there are two ways you will receive the DEVICE: LOCKED, or UNLOCKED. The SCT DEVICE does NOT lock to a VIN number of the specific vehicle. If an SCT DEVICE has been returned to stock before the truck is gone, this is considered UNLOCKED. The tunes that are stored in the device CAN be used on a different truck but ONLY if you have the SAME YEAR and SAME CAB CONFIGURATION AND SIMILAR MODS. (Not recommended, but it is possible). If you purchase an UNLOCKED device, you can also elect to order new tunes (Torrie charges $200 for N/A and $250 for s/c turbo/nitrous tunes). Once you do this, the device has now been used on a second vehicle, and there is still one more time the SCT can change vehicles before it becomes LOCKED. If you purchase a LOCKED DEVICE, either by it being used on 3 vehicles, OR the previous owner did NOT return the SCT DEVICE back to STOCK, then YOU MUST RETURN THE DEVICE BACK TO SCT TO UNLOCK. This cost is $150. Once the device is UNLOCKED, you can then purchase NEW tunes. (Torrie charges $200 for N/A and $250 for s/c turbo/nitrous tunes). You can do the math, as the prices listed are subject to change, and DOES NOT include the actual purchase price from the seller.