Stability Control Failure
 

I know this may seem a little redundant as i have seen many post on this topic. I recently purchased a 2005 saab 93 linear, and sometime i get the stability control failure message and it will either go off while i am driving or it will go off when i turn the car off sometimes it will come back on immediately for a couple of days and sometimes it will go off and stay off for three or four days. should i be concerned what parts should i consider replacing as this message is getting pretty old.