Air Bag RCM

I have a fault code of B1342 on my airbag RCM, which I found out means there is an internal fault in the RCM and it needs to be replaced. I have ordered a used RCM that has the exact same part number. When I get it will I have to have it formatted? or sense it is the same part number will it just work without formatting. Will I harm the replacement RCM if mount it back in the car and plug it in and see if it works?