Airbag fiat 500, Multiecuscan or you need to open the ECU ?

[life]

Hello guys,
kindly hope someone help me clarify the ideas.
I'll keep this short, one day while caricavo a mobile in the car, I slammed against the dashboard, and from that moment the game faulty airbag in my fiat 500 1.2.
I brought the 500 in the fiat, and to diagnosis by " the failure of drivers " and " power failure unit ", from the time that they asked me more than 500 euro to replace it, I ask you to help me find an alternative.

I saw the program multiecuscan, elm327 and yellow wire, from what I have read you should remove the light.
While others say that we need to open the ecu and work on the eeprom.

Which of the two solutions for me ?
multiecuscan is easy to use and with a few euros, I could solve the problem, but I don't know if it would work.

Thanks in advance.

[ciccio84]

With multiecuscan you can reset the light only when all the components are connected but in this case, you have a problem with the supply of the control unit, then you would need a schema in order to actually see if we get all the signals, and after that is done decide how to take action!

[giuseppe89]

If you are sure that when you went to fiat they are unable to communicate with the ecu of the airbag, this makes me think of an error due to a voltage sag, and then reset and see what happens...(this can be done with multiecuscan) then, if the communication was not happening with this unit and you have said that there could be a power problem perhaps has failed its the ecu...I happened upon a great point in 2012 that should fail, the ecu without a bump it drops in voltage, and if I'm not mistaken it should fit the same ecu of your car(in this case, it must be opened and repaired, or the problem is fixed in the file with a programmer).

[life]

Thank you both, the fiat was close while the controlled and the control unit, communicated, went out, in fact, the two errors of which I spoke. I also asked him if anything happened to the pretensioner seen the slight bump that I have given on the dashboard , but also control those that have seen the resistors were ok.
The ecu I also tried to remove it to see the code, and clearly detached me from other failures (belt-passenger front airbag etc), clearly when they leave. Maybe it is a sign that the ecu is still alive.

In any case, I like to put hand on things, I bought l need to try with multiecuscan, but I also picked up a control unit used ( guaranteed not accident-free, I hope) in order to have the alternative. In the best case, if I fix it with multiecuscan rivendo the control unit.

The thing, however, that it is clear to me is : With multiecuscan if I can raise the lamp, the control unit then returns to efficient? that is, in the event of an accident work for me?