Will not start after replacing the battery, security system?

I assume the engine will not crank over; can I ask if the security light is flashing when you turn the key to crank position? If everything goes out, lights etc. The battery cables are loose or corroded here is a guide to help you fix the problem:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

If the connections are okay and the security light is flashing please reset the system which is done by removing the negative side of the battery, with the cable loose from the negative side of the battery, hold it to the positive terminal for 1 minute this will discharge the memory capacitors in the BCM and PCM allowing the system to reboot. Then reconnect the battery. Let me know how it goes.

Hi, does your vehicle have the KARR alarm system? If it does, the override button is on the lower panel on the driver's side. See snapshot of instructions below. Hope this info helps. I had that issue with my wife's Honda Fit. I had to manually override with that button.