07 Tundra Changed my battery and Anti theft alarm keeps going off

Recently changed my battery and when I went to connect the negative terminal, the security alarm started blaring and the truck won’t crank. Anyone know how to disable or reset this? Thanks.

 

key in the ignition and turn it to on 2 times quickly, don't start the truck. Should disable the alarm system. If you do it correctly then the red light on the dash will blink 2 times per blink quickly. To turn it back on do the same thing, the blinking shoukd stop. When reconnect the battery I hold the key fob because the alarm goes off every time. I would also check the negative terminal and ensure it's on tight.

 

I tried that today but no luck. I’ve tried about everything I could find on forums and no luck

 

Did you try the key in the driver side door?

Lock and unlock the driver door with the key back and forth several times.