IF you had bought MaxiCheck Pro, you can do exactly what your want. When you get into the older GM's, it gets a little tricky, but it bets spending 4k. If you go to GM 2004, select GM Truck. Then select Light Truck, then Letter K. Then do 8500 or less. There it is, works like a champ.
Also, when you buy it, and its like a difference of 20 bucks, you have to update the software. You MUST re-format the SD card when you update the software or you will get aggravated.
Good luck.