Trouble codes 81, 82, 83 after truck shut off

After driving my K2500 for about 30 minutes without a problem, it randomly shut off as if someone pulled the keys from the ignition. I lost power steering, dash warning lights (I can barely see my glow plugs light when I turn the key), and engine power. And now the truck won’t turn over; it will crank I can hear the lift pump and can hear the computer purring and dash warning lights don’t work, and it has codes 81, 82, 83. Pointing me to the 1-2 solenoid, 2-3 solenoid and the TCC.

Could this be an issue with my ECM/computer? I don’t think it’s a mechanical or fuel delivery issue since I can get the truck to crank but I’m losing something, and she won’t turn over.

Please help. Many thanks.