I have a 2007 Chevy Silverado 1500 Classic WT with 4.3 Vortec and I just installed a factory 6 CD Changer radio that I bought on ebay and had it unlocked at a nearby Chevy dealership. Everything on the radio works perfectly except the sound output is not loud enough. Since I just got a job at a Chevy dealership in the quick lube zone, I tried to use the Tech 2 to somehow adjust volume, but I can't do it since I only know how to look up trouble codes with the Tech 2 and I thought the Tech 2 can do adjustments on radios? Some technician at my dealership told me it could have been programmed for a Bose system, which my truck doesn't have or the speakers could be the problem.. Do you know what can I do to fix it?