theft system prevent vehicle from starting

There could be a number of reasons for this. We need to start with checking for codes as there is normally a code that will tell us what is happening.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Once we know what codes we have we can get that info and figure out what this could be.

Here is a basic guide that will help with how to try and disarm this system:

https://www.2carpros.com/articles/how-to-reset-a-security-system

If this info does not help then our options are going to be limited without knowing what codes (if any) we have.

Let us know and we can go to the next step. Thanks