Ok sorry 03 Tahoe LT and the computer said unknown driver.
You mean the instrument cluster information readout just below your gear selected readout displayed "unknown driver"?
After scratching my head thinking what on earth is this guy smoking...i got it! The unknown driver is referring to driver 1 and driver 2 for power seat and mirror settings. Your tahoe will memorize 2 drivers settings and move them automatically when Key FOB 1 or 2 is used OR button 1 or 2 is pushed on your drivers side door near window switches. This module I believe is under your driver seat. Try this first, disconnect battery both neg and pos AND....pay attention here closely and follow exactly. Take neg and pos battery wires that are DISCONNECTED from battery and touch the two wires together (battery not connected at all) for 60 seconds. Then reconenct to battery and see if all is well. Im not sure if this is related to your no start condition.
Ive gotta hand it to you, I own not one but two 2003 Tahoe LT and have never seen any goofy shyiet like this out of them. You got gremlins or a black cloud following you!
Check underneath both front seats for wiring harness pinched in seat metal track. Check fuses for power seats.