There are 2 methods to program a module from a GM car using a Tech 2 scan tool:
If you’re trying to program a module, there are two methods. I don’t remember the exact terminology but one is pass-through and the other is using the Tech 2 as a go-between.
The pass-through is to use with a laptop in the vehicle and it just uses the Tech 2 as the connection between. This is the fastest and easiest way to do it.
The go-between method is for when you can’t bring the computer into the vehicle and uses the Tech 2 as a go-between. You connect the Tech 2 to the vehicle and download the module information that you want to program. Then you disconnect, run to the computer running Tis2000, connect it to the computer and download the programming information for that module, disconnect again and run back to the vehicle, connect it and it automatically programs the module. It can take a long time depending on the module (PCM is the longest).
However, if you’re getting crank but no start, it’s not the Vehicle Theft Deterrent (VTD) as it wouldn’t even crank if that was the issue.