if airbag its self the resistance has change due to age and corrosion or a open circuit within the ecu will read this as broken circuit of a fire circuit, as fault goes after disconnect chance are the airbag its self is faulty,, that said if that dont cure it then a airbag module could be at fault or wiring to it, as breaking the circuit should throw up different code than fitting a out of spec airbag, seeing these issues alot where reader says one thing and turns out being something else and without having the pinouts of module with the resistances it near impossible to locate a fault without replacing stuff ie start at most likely and cheapest,, gen one mini suffer abs pumps for a past time,