Volvo Repair: 240 3rd gear, volvo service, gear shift

Question
I was driving on the highway and somehow, my automatic 240 with 240,000 miles, shifted down to 3rd and an arrow is shown on the dash, i think it has to do with the small button on the gear shift but i press it and nothing happens, how do i get it out of this 3rd gear mode? If the button is broken, what will it involve to fix it?  

Answer
Hi Kyle,
       ...
       It seems like a part has failed...check out the overdrive relay..it directly controls the overdrive mode on the trans.
            Bring car to Volvo service dept...or a competant mechanic that knows Volvo..
                Good Luck,
                       Bilbo