cobalt06chevy

Sorry if this has been posted before but my girlfriend owns a 2006 cobalt ls 2.2L and the other day while driving, her service airbag light came on and the message on the dash Service Airbag Soon. she did notice that this morning when turning on her car the light was off and about 30 mins into the drive came back on again. has anyone else had this problem and what was done to fix it. ive read on some google searches that you have to replace the whole pass side airbag module. im really hoping that is not the case because she doesnt have that kind of money to drop into her car. Thanks for any feedback