2004 Chevrolet Express Logo
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Anonymous Posted on May 05, 2014

Why won't 2004 chevy express start when security light is on?

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Marcos Lopes

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  • Chevrolet Expert 259 Answers
  • Posted on Apr 23, 2015
Marcos Lopes
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Joined: Oct 29, 2011
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Because ignition key has a chip that allow ecm to start the engine if you are using a key copy it will not working, if you don't have the original key with the chip on it you must take vehicle to the dealer to disable the security program on engine computer

5 Related Answers

Anonymous

  • 1010 Answers
  • Posted on Jun 25, 2008

SOURCE: 2003 chevy express cutaway

Odd, and hard to figure out without hearing
the "scratching". I'd say run over to
the local GM service bay, and ask them to
do some inspecting. It's all covered under
a warranty right now I suspect, so have the
anomolies checked out while you can for free.

Best I can offer without being there to evaluate.

Let me know what they discover.

ALARMTEK
CARALARMMAN.COM

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john h

  • 29494 Answers
  • Posted on Oct 27, 2009

SOURCE: 2004 chevy 3500 express passenger van transmission

if ur replacing it remove front grill disconnect both lines and carefully remove retaining clips from radiator if replacement is original eguipt mount & reconnect --if its a universal follow instructions usually cut off fittings and use clamps and hose to hook up

raj somaiya

  • 5370 Answers
  • Posted on Mar 03, 2012

SOURCE: Ran 99 chevy express hot won't start even with a

Car not starting or turning over indicates towards multiple possibilities. It can be issue with battery or weak battery. But if battery checks out ok, then it can be starter issue or faulty alternator or problem with low fuel pressure or no spark at spark plugs due to dirty spark plugs or faulty ignition coil or injectors getting cracked or dirty and needs to be cleaned.


To confirm the problem, the basic troubleshooting is required.


Click this link below and follow the troubleshooting:------

http://technoanswers.blogspot.in/2012/02/car-starting-issues.html

---------

This will help.

Thanks.

tayjoejoe

Joe Taylor

  • 2229 Answers
  • Posted on May 23, 2012

SOURCE: security light on 2004 chevrolet express van won't go off

The security light is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM. (Theft Deterrent Module) The TDM is what tells your computer that the correct key is being used and that it is "OK" to allow the vehicle to start and run. These 3 parts must be in CONSTANT communication. If the key is in the ignition, then these parts are sending important signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, (normally due to a failing/broken part) the car goes into antitheft mode. The car misinterperates this and thinks its being stolen or hotwired because it is NOT getting that signal from YOUR specific key. There is where the security light turns on and shuts down your vehicle. So basically, if that light is on, your system has some sort of failing part. This can start as an intermittent "no start", to your vehicle not running for days at a time, to the vehicle NEVER starting again. The problem is electrical and computer based, so don't count on an easy reset button, or the problem fixing itself. The hard part is isolating which part is the problem. You can spend a thousand dollars through a mechanic very easily. I have had great luck with bypassing the entire system. This way the problem will never return. It actually CAN'T ever return because it is eliminated. This can also be done yourself at a much cheaper cost. Read through this link very carefully. You'll find alot of information and pictures, along with ways to help you fix this.



http://vatspasslockpasskeysecurityhelp.yolasite.com/

tayjoejoe

Joe Taylor

  • 2229 Answers
  • Posted on Jun 26, 2012

SOURCE: 1999 2dr chevy tahoe security light flashes truck won't start

The security light is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM. (Theft Deterrent Module) The TDM is what tells your computer that the correct key is being used and that it is "OK" to allow the vehicle to start and run. These 3 parts must be in CONSTANT communication. If the key is in the ignition, then these parts are sending important signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, (normally due to a failing/broken part) the car goes into antitheft mode. The car misinterperates this and thinks its being stolen or hotwired because it is NOT getting that signal from YOUR specific key. There is where the security light turns on and shuts down your vehicle. So basically, if that light is on, your system has some sort of failing part. This can start as an intermittent "no start", to your vehicle not running for days at a time, to the vehicle NEVER starting again. The problem is electrical and computer based, so don't count on an easy reset button, or the problem fixing itself. The hard part is isolating which part is the problem. You can spend a thousand dollars through a mechanic very easily. I have had great luck with bypassing the entire system. This way the problem will never return. It actually CAN'T ever return because it is eliminated. This can also be done yourself at a much cheaper cost. Read through this link very carefully. You'll find alot of information and pictures, along with ways to help you fix this.



http://vatspasslockpasskeysecurityhelp.yolasite.com/

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2004 chevy express 3500 first the fuel pump was acting up and all the Gages were going up and down. Now the van won't start/run and the security light is off at all times? Any related problems known?

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My 2004 Chevy suburban won't start but there is a locked padlock on dashboard , is this why?

sound like problem in the theft security systm,try this insert another key in the ignition switch, the other key could be worn where pcm and bcm dont recognize it. and switch ignition on engine off watch padlock symbol with ignition switch left on 10 minutes the padlock symbol will extinguish or turn off then you will turn off ignition switch wait 5 seconds then try starting vechicle if start your theft security failing need let dealership check it out.
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Security light on 2004 chevrolet express van won't go off

The security light is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM. (Theft Deterrent Module) The TDM is what tells your computer that the correct key is being used and that it is "OK" to allow the vehicle to start and run. These 3 parts must be in CONSTANT communication. If the key is in the ignition, then these parts are sending important signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, (normally due to a failing/broken part) the car goes into antitheft mode. The car misinterperates this and thinks its being stolen or hotwired because it is NOT getting that signal from YOUR specific key. There is where the security light turns on and shuts down your vehicle. So basically, if that light is on, your system has some sort of failing part. This can start as an intermittent "no start", to your vehicle not running for days at a time, to the vehicle NEVER starting again. The problem is electrical and computer based, so don't count on an easy reset button, or the problem fixing itself. The hard part is isolating which part is the problem. You can spend a thousand dollars through a mechanic very easily. I have had great luck with bypassing the entire system. This way the problem will never return. It actually CAN'T ever return because it is eliminated. This can also be done yourself at a much cheaper cost. Read through this link very carefully. You'll find alot of information and pictures, along with ways to help you fix this.



http://vatspasslockpasskeysecurityhelp.yolasite.com/
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Won't start lights come on but engine won't do anything

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