Mazda Repair Questions? Ask Mechanics for Answers ASAP
If the immobilizer light is not lit, and many other functions don't work, I would say the BCM (body control module) has been water damaged, fried.
The key is read by the BCM.
The BCM enables the start relay if a programmed key is read.
With the ignition on, hotwiring the starter gets the engine running.
How bad was the flooding in the car?
Sorry for confusion here Roeland.
I would contact the seller.
It has some other system that I can't help you with.
It might have some secret way only the owner driver would know, that they should have shown you?