Dear Tom & Ray,
General Motors has a anti - theft system called:
" Passlock "
It uses a signal from the ignition switch,
fed into a electronic box under the dash board,
which stops gas flow , if the signal is absent.
I’ve found a method of defeating this system, should it be defective , because of a bad ignition switch.
It requires cutting the ignition switch wire,
while the engine is running, causing the system to fail enabled. And, that condition will remain enabled , as long as the battery is connected.
I’d like to duplicate that signal , comming from the ignition switch , so I can replace the battery when necessary.
What is that signal?
Advising people on how to defeat anti-theft systems troubles me due to I do not know your true intentions.Passlock system theory of operation info is avialable in the FSM.