04 silverado shutdown

my 04 silverado's pcm will not communicate with the tech2 scan tool or my diablo predator. the truck is completly shutdown. will not turn over, crank, or run. when the tech 2 is plugged in it has a response of "is ignition on?". same response on the predator. any ideas of what the problem is? it will not even program a new pcm.

What happens when you turn the key over? Do the lights come on? Will it do everything except start?

Does Pin 16 have 12 volts? In Pin 4 connected to ground?

http://www.obdii.com/connector.html

The OBDII connector shares the same fuse at the cigarette lighter. Does the lighter work?

Check both ends of both battery cables for clean secure connections.

//2000CAYukon

that is correct, all lights come on, gauges work,radio works, everything except it will not turn over. i had a diablosport predator program on the truck, when they backed it out to put the oem program in, this is when the problem occured. it even has a new pcm and bcm and will not read any information. this truck has been down for 2 weeks now!!! help!!!

that is correct, all lights come on, gauges work,radio works, everything except it will not turn over. i had a diablosport predator program on the truck, when they backed it out to put the oem program in, this is when the problem occured. it even has a new pcm and bcm and will not read any information. this truck has been down for 2 weeks now!!! help!!!

with a meter check all fuses.....