How do you reset anti-theft system on a 2005 Nissan Titan?

To reset the anti-theft system on a 2005 Nissan Titan, first ensure that all doors are closed and the key is out of the ignition. Insert the key into the ignition and turn it to the "On" position without starting the engine, then back to "Off" and repeat this process a few times (usually three times). After that, leave the key in the "On" position for about 10 minutes until the security light goes off. Finally, turn the key to "Off" and try starting the engine.