# Security switch in Chevy S-10 **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** pump, keys, s-10, gasoline\ **Created:** [September 18, 2007, 10:59pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820 "2007-09-18T22:59:19Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![richvd](https://avatars.discourse-cdn.com/v4/letter/r/eb8c5e/32.png) [@richvd](https://community.cartalk.com/u/richvd)\ **Post date:** [September 18, 2007, 10:59pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/1 "2007-09-18T22:59:19Z")
I have a 2000 chevy s-10 x-treme edition and I’m having an odd problem. Some times when I start up the truck with out giving it some gas, it will start up and immediatly die and then the security light on the dash will start to flash. The truck will not start for a good 10 minutes while still turning over. I have looked into this and aparently it has a security feature that will turn off the fuel pump if the correct key isn’t recognized. The key doesn’t have a chip in it and I got a brand new factory cut key. The other wierd thing is that while driving sometimes the security light will come on when I hit a bump or just am driving along. The truck will not turn off or anything but will still drive just fine. I have also noticed that I can make the switch turn on by rapidly adjusting the tilt stearingwheel. I have no clue what to do. My local mechanic said that he didn’t even know where the switch was. Any and all suggestions would be appreciated. ---
**Author:** ![miners](https://avatars.discourse-cdn.com/v4/letter/m/9e8a1a/32.png) [@miners](https://community.cartalk.com/u/miners)\ **Post date:** [March 25, 2008, 7:20pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/2 "2008-03-25T19:20:50Z")
I’m having the same problem with my 99 s-10. No one can help me either. ---
**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\ **Post date:** [March 25, 2008, 8:14pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/3 "2008-03-25T20:14:43Z")
I would guess you’ll need to have the ignition system traced to find the fault. You mentioned you can affect the switch when you move the tilt steering column, perhaps there is a damaged wire. ---
**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\ **Post date:** [March 25, 2008, 10:31pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/4 "2008-03-25T22:31:05Z")
If you can wait until tomorrow I can get into the wiring diagram and see what can be done to disable the system. I recently was looking at a wiring diagram for a GM security system and it seemed to me that it was possible to disable the system by cutting a specific wire. I’ll do some checking and get back to you. ---
**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\ **Post date:** [March 26, 2008, 12:38pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/5 "2008-03-26T12:38:53Z")
I am sorry to say but I don’t see any way to disable or by-pass the security system. The system uses the key sensor to send a signal to the BCM, if it doesn’t see the correct signal it sends a voltage signal to the VCM to shut down the fuel injectors. What I can’t find is how they shut down the fuel system. Do they just shut off the fuel pump relay? Does it not fire the injectors? I can’t find it in the wiring diagram. I know that if you get a new key cut you have to have it programmed to the vehicle with a scanner. ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [March 26, 2008, 12:55pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/6 "2008-03-26T12:55:15Z")
I lose track of when they released the various incarnations of Passlock. There’s a ton of information out there on ways to reset and defeat all versions of Passlock. Some are as simple as cutting the yellow Passlock data line and waiting with the key in the run position for 10 minutes. There are chipped keys, chipped tumblers and RF keys. The bypass method depends on the configuration to some degree. When the proper code is not presented to the controller, it disables the fuel pump and injectors. It’s all done internal to the controller in the programming. ---
**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\ **Post date:** [March 26, 2008, 1:49pm UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/7 "2008-03-26T13:49:06Z")
I saw one version where all you had to do was by-pass a relay to disable the system. I can’t remember what vehicle or year it was for but it must have been for an earlier version. ---
**Author:** ![richvd](https://avatars.discourse-cdn.com/v4/letter/r/eb8c5e/32.png) [@richvd](https://community.cartalk.com/u/richvd)\ **Post date:** [May 11, 2008, 8:05am UTC](https://community.cartalk.com/t/security-switch-in-chevy-s-10/4820/8 "2008-05-11T08:05:31Z")
So I got it fixed. It was the security interlock switch that sits just above the tumbler. cost about 400$ to get it fixed. Hope you can get it fixed.