Issues with starting vehicle?

I took the battery out to reset a code that was brought to my attention when I reconnected it the key didn’t work anymore. After looking further into that issue, I found out about the security feature and resistance pellet in the key. My problem is when I use the ohms meter to read the resistance on the key. It says zero. I don’t know what happened for it to just quit reading anything. Is there a way to bypass this or replace the ignition even?