2011 Hyundai Santa fe GLS 3.5L No system found on scanning

Question

I have 2011 Hyundai Santa fe GLS 3.5L with deployed both driver wheel and front passenger airbags. I replaced both of them, also both seat belts, and I sent the control module for resting.
The airbag still on and during computer scanning of airbag system the result was no system found, the electrician made scanning of the engine, also the result was no system found.
The front passenger light continued to be off when some body sat on the front seat.
I tried with another control module the front passenger light became on, but the airbag light still on and with system scanning the result was no system found.
Please I need an explanation of this ( no airbag system detected )