Question about 1999 Chevrolet Tahoe
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.
Posted on Jun 26, 2012
Take the connector loose that is plugged into your ignition, has 3 small wires, ( orange w/black stripe, red w/white stripe, yellow) WHILE TRUCK IS RUNNING.
After disconnected security light will remain on ut truck will start
Posted on Jul 18, 2012
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Your Passlock may need to relearn the ignition keys, if the
ignition lock has gone bad like my in-laws Grand Am Gt, here is what i
did so they will not get stranded any more. Buy a Passlock by pass
module for around $70.00. You can orderone from GMPASSLOCK.COM in the
mean time try resetting the Passlock. Good luck
Ignition keys relearn takes about 30 min to do. 30-Minute Learn Procedure 1. Turn ON the ignition, with the engine OFF. 2. Attempt to start the engine, then release the key to ON; the vehicle will not start. 3. Observe the SECURITY tell tale light. After approximately 10 minutes, the light will turn OFF. 4. Turn OFF the ignition switch, and wait 5 seconds. 5. Repeat steps 1 through 4 - two more times - for a total of 3 cycles of 10 minutes. 3x10 = 30 minutes. The vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch turn from OFF to CRANK Important: Turn the Ignition Switch OFF. The vehicle learns the Passlock Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle. 6. Start the engine. The vehicle has now learned the Passlock Sensor Data Code and/or password. 7. With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles. Without a scan tool you may have momentary starter interruptions while history clears itself.
Posted on Dec 18, 2009
honestly, any number of thing's could cause the security light to come on, i would go to my local auto store and ask them to run a coad scsnner to find the problem, good luck
Posted on Dec 21, 2009
If the light is flashing it may be an issue with the passlock sensor.Here is a process you can try to reset the passlock. If this process does not work you may need to replace the ignition tumbler and passlock.
PASSKEY LOCKOUT RESET ALL GM CARS 1999 AND UP
1) Put the key in the ignition and turn to the "ON" position. Leave it that way for 10 minutes. After 10 minutes turn the key and take it out. Repeat this process (2) more times (3 times, 30 minutes total) This should reset the PASSKEY system to recognize your key.
Posted on Mar 08, 2011
i am in training for a mechanic and all you have to do is put a battery charger on it and leave the ignition on it needs to re learn the system
Posted on Jan 17, 2010
Tips for a great answer:
Jul 17, 2013 | Cars & Trucks
Mar 15, 2013 | Cars & Trucks
Feb 21, 2013 | 2006 Chevrolet Colorado
Jun 02, 2012 | 1999 Chevrolet Tahoe
Mar 18, 2012 | 1998 Chevrolet Cavalier
Feb 13, 2012 | 2003 Chevrolet Tahoe
Aug 28, 2011 | 1999 Chevrolet Lumina
Aug 21, 2011 | 2003 Chevrolet Tahoe
Jun 09, 2011 | 1997 Chevrolet Tahoe
3,602 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: