Security system wont allow car to start for no apparent reason

What year is it ? Does the security light flash when try to start ? Anti - theft system will not allow engine to crank .

Turn the key to acc and wait about 10 minuter for the security light to go solid or stop blinking

This happens due to a failed or failing antitheft system. When the system cant communicate properly, it will disable your starter or injectors and show the SECURITY light. Go to this link for info and ways to beat this system yourself.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

THERE ARE MANY POSSIBLE CONDITIONS THAT COULD PREVENT YOURCAR FROM STARTING. 1. NUTERAL SAFETY SWITCH IF THE CAR HAS AN AUTOMATICTRANSMISSION. 2. CLUTCH POSITION SWITCH IF THE CAR HAS A MANUAL TRANSMISSION.3. BRAKE PEDAL SWITCH. MANY NEWER VEHICLES HAVE A SWITCH ON THE BRAKE PEDAL ANDIF THE PEDAL IS NOT DEPRESSED WHILE TRYING TO START THE CAR, THE CAR WON'TSTART. ANOTHER POSSIBLILITY IS THE SECURITY SYSTEM. DOES THE CAR HAVE ASECURITY CHIP IN THE KEY? THESE ARE SOME OF THE MOST COMMON REASONS THAT A CARWON'T START FOR NO APPARENT REASON. HOPE THIS HELPS.

Let the car sit undisturbed for 10 - 15 minutes, then try to start it. Check the owners manual if you have it. Sometimes, on various cars letting them sit awhile will allow the system to reset itself. On others sometimes rapidly turning the key from off to on, without turning to start 3 to 8 times within 10 seconds and then on the last turn to the on position leave it there until the horn chirps, at that point turn the key directly to start, or turn off first and turn to start. If all this fails, a GM dealer can reset the system.

You might have to reset the security system. It should tell you how to do this in your owners manual.

if the security light is flashing try to shut all doors and using the key lock and unlock the drivers door from the outside. This should disable the security system and allow for regular operation. i hope this helps

The security system (VATS/PassKey) is having problems, it's typical on those cars and it gets worse till the car won't start anymore. You can find a great write-up here: http://newrockies.ca , it was the only thing that saved my Park Avenue with the same system.

try disconnecting the battery should reset the system