Volvo: 1997 Volvo 960 Service Light, 1997 volvo 960, volvo 960

Question
Recently my service light does not go off right away when I start the car up.  After I drive for a few miles it goes off, or if I turn the car on to accessories and let it sit for a few minutes before cranking the engine the service light goes off and I start the car.  What would be the reason for this.  I am guessing that when the service light shows up a trouble code is written and then another code is written when it goes off.  Again I am guessing but that would probably cause me to fail inspection because the diagnostic looks at the three most current codes registered and one of them is a failure.  Is this a true assumption?  Thanks for your help

Answer
Benson,
If it is the service light that is what it means, the car is needing service. It is a mileage counter and comes on ever 5000 miles. Pull out the small rubber plug on the dash speedo cluster and push the reset button. That will turn off the light for 5000 miles.