2004 GMC Vortec 5.3 computer
 

Looking for a system that I can hook into the ECM that sits on either the A pillar or its own box on the dash, that I can change the motor and trany settings by just pressing a button. Like if I want to put it into super cruse mode (cut off cylinders) or trailer mode, etc. The truck is old enough, and I have seen the ones that you plug in and take out after it reprograms the ECM. Saw it on one of the truck shows, but can't remember. It does have the trailer mode button the shifter.

Hypertech has 1 I beleive, but a good tune is better as most people will tell you...