when will the security feature activate

If your have a passkey system in that car - keys with the pellet embedded in it...

If the key pellet is the wrong value, the Theft Deterrent Module (TDM) will not send signals to allow the starter to engage or fuel to the engine. The TDM will shut down for ~3 minutes and the SECURITY lamp will remain lit with the key ON or OFF. When the ~3 minute timer has expired and the key is cycled from OFF to ON, the TDM timer is reset. If you try a key with the correct pellet value, the engine should start and run. SECURITY lamp should be off. If there is still a problem with reading the key, the TDM will light the SECURITY lamp and start the ~3 minute timer again.

If the sensing contact circuit is open or shorted (cannot read the key) or a defective key is used at the time the ignition is turned ON, the SECURITY lamp will flash at a rate of once per second and the engine will not start. No three minute lockout will begin.

The SECURITY lamp will also flash at once per second if a new, unprogrammed TDM is installed and there still is a defect in the key reading circuit. The engine will start in this condition, though.

The lock cylinder circuit is continuously monitored. If a fault lasting 1 minute is detected, the SECURITY lamp will light. If the fault then goes away for 1 minute, the lamp will go back off.

If the system detects a fault with the lock cylinder circuit after the engine is already running, the SECURITY lamp will light. The engine will be able to be restarted. This is called “fault enable mode”. (The system saw a good reading from the key at one point during a previous ignition cycle before the failure. So, it considers it a problem and not someone trying to steal the car.) When in fault enable mode, PASSKey protection is disabled until the problem is repaired. Once repaired, the SECURITY lamp will go out about 1 minute after the key is turned on.

From http://shbox.com/1/pass_key.html