I don't recall what the cutoff date was for the under hood diagnostic port, but if you have one then it is easy to reset the lights. Open your hood and look on the passenger side of the car. There will be a black box of sorts to the left side behind the headlight assembly. (About 12"X9"X9") Attached to the front of the box should be 2 little rectangular boxes. Lift the cover off of them to reveal the 1-7 A and B ports. If these are there, then you are in luck. If not, you still may have a chance. On the dash, there may be a rubber grommet consealing a reset button. (Not to be mistaken for the clock H/M and/or trip meter reset button.) If there is a reset button there, just press and hold while the ignition is on to reset the light. For some great detailed info, check out www.volvospeed.com
and navigate to the service and maintenance section. Under the "Bay 13" area, find service lights. Good site for info, very trustworthy source.