Volvo: Check Engine Light/Emission System Service, obdii code reader, volvo dealer

Question
Have a 2001 V70 XC.  Check Engine Light just came on with a message saying "Emissions System Service" or something like that.  I am looking to reset the light, but understand from reading your info that there is no way without a OBDII reader tool etc.  I believe this message was triggered by a very cold day and poor fuel causing a miss-fire(not sure).
THE QUESTION is, does the OBDII reset itself if it no longer detects a problem or does the code stay in the OBDII and message displayed until Volvo squeezes more money from me?  I understand that it is important to have good diagnosics, but I just purchased the car from a dealer and if I need to go into a volvo dealer everytime the car hiccups it will be more bother than it is worth.  

Answer
Hello Sammy! Yes. The computer may reset itself if the fault is gone. It ususally takes about 100-200 miles of driving. You will need a special OBDII code reader or Volvo special tools to read and reset the code. There is no other way. It is best to have the car checked by a qualified Volvo technician to make sure there is no major issues.

Jimmy