Ive had that problem before running vz ls1 in mafless mode, from memory the "predicted airflow vs rpm vs tps was causing safety mode to activate , was also getting code p1514 ,and dash displaying "saftety mode" try raising the numbers.

The data on ls1 memory ic is byte swapped as well , so you will need to byte swap data to make sense of it.

37AA isn't your seed ,that's the reply given for security timeout error , hence why you get it when trying again before 10 sec security timeout.
From memory the pcm will give a reply of 0000 when it is already unlocked ,for eg mec is set.

Try sending ATSP2 and / or ATE0 , sometimes elms wont auto detect vpw protocol properly .
Besides sending ATSP2 it should work on defaults , if you still cant get it working let me know and ill add a routine to the adx so it sets up correctly on connection.

Getting the engine to crank doesn't disable vats , if vats is active even if you have it cranking you will still have no injector pulse .
Get someone who knows what there doing to disable vats.

Operating System Enhanced.

What Antus said still applies to the vz ls1 there are fuel sender level/voltage pids , also although it wont set engine light if there is a fuel sender error it will report codes
P0461
P0462
P0463

Just tested it ,works fine ,gets seed and key ,osid no problem ,seems to crash if you hit "get vin", but that doesn't matter.
Tried a brand new elm327 from china , wouldnt work straight out of packet on default settings
Only commands I sent to get it working were
atsp2
atl1

If the car starts and runs fine now ,and all other dash info is good except fuel guage ,checking sender resistance would be good place to start.

There are 8 calibration modules on vz ls1 pcm, all the fuel guage conversion/config settings are in the fuel system cal module.