It can be vats passkey or passlock anti theft system that is going bad causing your issue. Tbitpi 89 92 pin b6 might be a white wire instead of dark blue.

Installation Diagrams
Vats wiring diagram. This is a diagram for gms vatspasskey anti theft system for the if bypass module. However in the passlock system the resistor has been placed inside the ignition switch instead of the key. Gm vehicle anti theft system passkey ii relay wiring diagram. Vatspasskey diagram for 8 pin harness on if bypass module. If i am reading this wiring diagram correctly then it looks like you could just skip the resistance reading all together and just go to the starter enable relay. Yellow and yellow white and white white yellow and black redwhite yellow and orangeblack yellow and brown purple and purplewhite.
Take the dark green. Gm vats known wire color combinations. May 29 the sensor then sends a signal to the control which gm has moved several the vat or vehicle anti theft was used primarily on corvettes. This is a similar device to the vats system in that there is a resistor present during the start cycle. Introduced in 1996 gm has changed the vats anti theft system to pass lock system. I was looking at one of my starting system wiring diagrams and i think i found an easy vats bypass that wouldnt require a trip to radio shack or ecklerscamaro.
How to override bypass a gm passlock 1 2 vats factory anti theft system passkey in gm cars there is a bundle of three wires which go from the body control module to the ignition switch. Wiring diagram for security light vats on a 1996 grand prix 31. I am going to share a secrete with you on how you can bypass these systems with very little effort. This is a really unique security system bypass kit that you can use to override your current factory theft system on your gm vehicle. The wiring from these leaf contacts travels down along the steering column wire harness where it connects to the vehicle harness at the base of the column. Grand prix if an illegitimate key is used or a system problem exists the light.
The vats signal wire will be labeled in your vehicles service manual as vats fuel enable wire or circuit number 229 and is normally a dark blue wire. Usually the vats wiring in the column is in an orange covered cable sometimes black and has a lone two wire connector no other circuits in the cable. The pin number at the pcm varies depending on the application. These are most often found inside orange sheathing coming from the ignition switch.