Immobilizer stopping the start

This sounds like you are having a larger issue with the key being recognized. I am not sure it is related to the vehicle running out of fuel or not but if the theft light now flashes and it didn't do this before then we need to start with checking for codes.

Here is a guide that will help with this:

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

Once we know what codes are in there then we will have a better idea on which way to turn.

However, if there are no codes then we are going to need to try and disconnect the battery and retest. Basically, this will force the modules to reset, and we may be able to get past the theft system.

If not, then we most likely have a key or immobilizer issue which should have some codes to point us in that direction.

Unfortunately, we don't have a manual on this vehicle, so we are going to have to try and figure this out based on the codes that we have.

Let's start with this info and go from there.