2001 LB7 Error: $0537

[garrettg.bpd]

I'm trying to read the stock tune from the pcm. The trucks history is unknown. The radio is stock. Pulled the radio fuses. One thing to note is that the under hood fuse box diagram on the lid and in the owners manual dose not match the locations of the fuses and relays. Tried unchecking high speed and checking try alt keys. No luck. Looked thru the forum just looking for some up to date insight.