Sorry,
I should have been more specific.
I'm not sure if I got it right.
Is there a transponder in the IR part of the key that communicates with DAS in the car (and allows the car to start)?

I'm not worry about the IR transponder to open or lock the doors (there is a manual lock on the driver door anyways).
Is there a way to disable the transponder in the key itself (making the car crank but never actually start)?

When I was ordering the replacement keys in the dealership, they've made a mistake first time around. The keys would open the doors, trunk, would turn in the ignition cylinder, but it would only crank and crank but engine would never run.
A different technician recommended a 'mickey mouse' key (has two 'ears' - looks like a mickey mouse, I guess..)
These keys arrived in couple days and the car started right away with both.
These keys are not flip type keys. (The transponder must be in one of the 'ears'.)

My hope and question is: Is there a way to disable the transponder(s) in the other key(s) I don't physically have? The car should then only crank, but not start, if the PO comes back with his key.
Thank you for your time and explanation.
M#.