Hi guys!! I have a problem. When a try to use my AL519 in a 1997 Chevrolet Silverado TBI 5.7 lt simply not connect, but i try in a 1996 P-30 with a Vortec 5.7 lts. and and im this engine there is no problem to read codes and parameters. In my own research i could find that maybe the problem is the reading protocol because in Vortec the protocol is PWM  or VPW. When i saw this i did a double check and i try to use the scanner in a 2000 C3500 TBI 5.7 and the same problem occurs. Already download the update pack for the model AL519 but when i try again the same problem occurs. Help please!!