Actually the a/b modules go bad rather often and they will definitely go bad if the airbag is not removed/replaced improperly. There is a sequence involved they requires the mechanic to remove the module FIRST then repair/place the airbag. Many dont follow the sequence and it causes the error light to display because now the module is toast. The dealership should incur the cost to replace the module because they didnt follow the sequence. In addition, the airbag will still operate properly even if the error light is lit. The airbag responds to sensor settings not the module. The module actually captures the data for downloading and communicates "intentions: between the airbags.