There's two work arounds for what you're going through. Find a replacement head unit 2nd hand and potentially pay someone to have your VIN added until you find one that doesn't have issues or...
Purchase the Tech II and have all the pay backs for as long as you own the truck. It all depends on if you already have some other diagnostic equip you may have invested in.
You can also purchase a preloved XP laptop with the GM TIS2000 software installed. You'll have the capability to add VIN to ANY head unit or other components. You can also charge to service other peeps Navi or Radios. $302 to your door.
GM TIS2000 2nd Hand Laptop $215 without shipping (+$72.00)
or you can purchase the Tech II that has three options listed below. A Tech II with no case. A Tech II with a case for free shipping or a Tech II with the MDI2 that allows you to run the TIS2000 software on any modern PC/laptop. Both the SP-23 options below come with the TIS2000 software to load into a XP PC/laptop (not included) so you can program VIN into radio or other components.
SP23-1 GM Tech2 with Carton Pack $269 $250 without shipping (+$72.00)
SP23 GM Tech2 with Case Pack $409 $379 Free Shipping
CD11 GM Tech2+GM MDI2 Carton Pack $617 $580 Free Shipping
The company listed above is where I purchased my
SP23 Tech II Feb 2020 on sale for $281.00. As you can see, the longer you wait, the higher the price. It took ten days to arrive and it's a spot on clone of GM's no longer used $3-$4K Tech II also made in China
The Tech II is easy to use. Simply navigating around in its menus, you'll stumble into most everything you need to diagnose issues. Watching a few online youTube videos will make you a master.
Expect to pay $75 to $150 for a service to add your VIN to a 2nd hand radio. If you've get the inkling to upgrade to a factory 11-14 Navi head unit with XM, built in hard drive for tunes, hard drive based NAVI and a DVD player, you'd benefit from one of these.
When you have the ability to instantly add your VIN to a 2nd hand unit, you can immediately verify if you got a smoking hot deal or return it as a lemon.