Unlike the VIN Unlock Code that allows a tuner to be used on another vehicle, the Duramax LML First Tune Unlock Code allows for the completion of the Install Download for the first time.
Unfortunately, H&S Performance (the manufacturer), programmed this requirement for owners of Duramax 6.6L engines and a stock H&S Tuner can not be used without it.
However, the Duramax LML First Tune Unlock is based on the tuner serial number, so it will only need to be unlocked once for the lifetime of the unit.
Note: DO NOT purchase this code unless your tuner specifically asks for it. If your tuner does not prompt you to enter this code (mentioning part number# 111006) during the first tune download, then you don’t need it.