2005 silverado using CA-520-A

I quit using code alarm remote starters because of the chevy trucks in 1999. the second ignition relay on the code alarm harness would loop the ignitions through the relay and interrupt the retained accessory power function of the truck intermittently. I now use Ultrastart units and have very little problems with them. for the aftermarket keyless entry feature to work on that truck (2005) you either need a doorlock interface or the wiring diagram for the locks that includes cutting wires and installing relays in the door. you will also need an anti theft system bypass. DEI makes a nice all in one unit, but I cannot remember the model number, 456g I think. The ultrastart unit you would need would be a tl1250 or new 1270.