In order to activate remote start on GM vehicles you need:
1. Find VIN car("new VIN"), which have remote start options (PRO code BTV).
2. Update firmware for BCM from SPS with "new VIN".
3. Change VIN in BCM from "new VIN" to your original VIN in order to odometer shows correct data. For this you need cheap CH341A EEPROM tool like this.
The following video show you how to setup the chip reader and program the chip.
It would probably be best to first make a backup of the chip in case anything goes wrong. Then you can view the contents of the chip. In the software, the left side of the screen shows the actual program, which is displayed in Hexadecimal numbers. The right side shows a translation in plain text.
On the right side, look for a string of numbers that look like a VIN. It is usually only a few lines down from the top. It is always missing the first number of the VIN. Replace it with your VIN (minus the first number) by simply highlighting each letter on the right side and typing in your VIN. Then program back the chip and you’re done.