Tried the normal reseting security system by the 10 min wait with key in ignition until security light turns off. Today car started up with no problem until I was on my way home and car staled. Security light wasn't blinking, but want to see if I can Reset the Security Computer without having to take it to a mechanic.

The only way to reset a computer is to take it to a dealer they have the codes needed to do this

The security system need to be reset, plug your charger back on the battery then turn the ignition switch on and leave it on untill the security warning light turns off (about 10 to 20 Min) then turn the key to off wait 5sec then turn the car on it should be good to go, this solves this kind of problem 9 out of 10. good luck

SWITCH IGNITION ON WITH MASTER KEY TO BE PROGRAMMED.TURN ON IGNITION KEY TO ON POSITION.SYSTEM LED SECURITY LIGHT WILL ILLUMINATE.LEAVE IGNITION KEY ON POSITION FOR 10 MINUTES UNTIL SECURITY THEFT LIGHT DISAPPEAR.THEN SWITCH OFF IGNITION SWITCH WAIT 5 SECONDS, THEN START THE ENGINE,THIS WILL HELP YOU FOR A WHILE BUT YOU NEED TO GET THE THEFT SECURITY SYSTEM SCANNED CHECK OUT AT THE GARAGE OR DEALERSHIP.

Leave the key in the run position until the security light stops blinking. This should take 10 minutes. Then turn the key off, wait 5 seconds and try to start it. The security light should be blinking again. Leave the key on again for 10 minutes. Repeat this 3 times. After the third time on the the next start it should start and run fine. This will reprogram your theft system.

You need to reset the Passlock security system to your Tahoe.

1. Attempt to start the car, let it stall, but DO NOT turn the key off! Leave it in RUN.
2. Wait 10 minutes or until the Theft System light glows steady instead of blinking.
3. Do not turn the key off, but start it immediately.
4. This should reset your Passlock system.

Good luck and thank you for using Fixya.

If that does not work then your may have to do the 30 min relearn. You do basically the 10 min thing with the security light trick instructions above. Here goes this only works if your secuity light is on.

Put key in ignition don't start the car but you want to turn the key all the way on and release it back to the on position wait 10 mins or till the security light stops flashing repeat this the exact same way two more times( dont take key out) ending in about 30 mins total time. this should reset the code to the computer and you should have no more problems with it.

Hello, Try this: Get in car, turn the key to start, when it don't start let key come back to run (do not turn off) The security light should be blinking, let car set for about ten minutes or until security light stays on steady at that time turn key off for 10 seconds then turn back on (do not go to start) security light will be blinking again wait 10 minutes and security light should go out. Turn key off, wait 10 seconds . Turn key on (do not go to start) security light will be blinking again, wait 10 minuets and security light will go out. AT THIS TIME TURN KEY OFF FOR 10 SECONDS THEN START THE CAR.

to reset the pas-loc turn the to on position 10 to 15 min.then turn the key off for a few seconds,then start the car/if your security light is on do this like i said for 10 to 15 minutes.the light should go off,then turn the key off and wait a moment then start it,you dont have to wait the 1/2 hour out

hold the reset button on the fuse panel and when it blinks let off of it and it will go away

Are you reffering to the alarm or the pass lock system that put the theft light on.....If its the alarm the put the key in the door and unlock it. If its the pass lock system put the key in the ignition and turn it on and try to start the vehicle. After it shuts itself off leave the key on for ten min until the theft light stops flashing the turn key off and try to start it again. This may take a few times....

The fab key activates the security system in the car, the ignition pass lock may need to be reset to your ignition key's. It Takes about 30 min to do. Try resetting the pass lock to read your ignition keys. 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. Good luck and hope this helps. The ignition keys has a resistor value for the ignition to read and after a few years the resistance may change and the Pass Lock has a had time reading it's value so you have to reset the pass lock to read the keys again.