# Passlock

**URL:** <https://community.cartalk.com/t/passlock/18210>\
**Category:** Maintenance/Repairs\
**Created:** [August 15, 2008, 1:13pm UTC](https://community.cartalk.com/t/passlock/18210 "2008-08-15T13:13:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![petermauro](https://avatars.discourse-cdn.com/v4/letter/p/49beb7/32.png) [@petermauro](https://community.cartalk.com/u/petermauro)\
**Post date:** [August 15, 2008, 1:13pm UTC](https://community.cartalk.com/t/passlock/18210/1 "2008-08-15T13:13:47Z")

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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?

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**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [August 15, 2008, 5:49pm UTC](https://community.cartalk.com/t/passlock/18210/2 "2008-08-15T17:49:35Z")

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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.