[TX '90 ZR1]

Got started troubleshooting. Here's where I am and need ideas.
With key in the start position the security light stays on steady. According to Marc's troubleshooting write up, this indicates the VATS system is shutting everything down.
Checked codes and get a big H53 after a small 1.-(nothing after the 1.)
Also get a big H46 after a small 4.-(nothing after the 4.)
Went to the FSM and code 53 has to do with the pass key. Followed instructions to read value as instructed in step 1. The number I get is 255.
After this I am getting lost. They are mentioning an adapter from J 35616.
I see no reference to code 46 in the CCM section. Code 46 in the ECM section refers to injector shut down. Could this be what I am seeing?
Anyone have any ideas or input?