Newbie Question - Can OBD-II show that an option is installed, even if it isn't malfunctioning?

Question

Specifically ..

a) is there a code that would show that the vehicle HAS an engine immobilizer installed and that it is functioning normally?

b) Would the code be the same across manufacturers, ie. Lexus, Audi, etc.....

I'm looking at this in the context of used vehicles, where it may not be known by the seller (estate sale for example) if the car had an engine immobilizer as standard equipment or as a factory-installed option.

Thanks for helping a newbie out.

Answer 1

A. The only time a code appear is if there is a fault detected,  B. Alarm codes belong to the BCM (body control module) they are usually manufactuer specific, If the alarm is factory there is a anti-theft light on the dash or a sign of a key (such as Honda or Chrysler). To scan for anti theft with a scan tool you will need a scan tool that read BCM and the anti - theft has to be manufactuer equipt, if it is aftermarket the scan tool cannot read it.