Image via WikipediaYears ago, I saved an email on resetting the dash service light on a newer Volvo, such as my C70. I finally needed to do this, dug out the email and sure enough it worked! No OBD-II required.
1. Turn the ignition to the "I" position (accessory), and hold down the trip meter reset button
2. While holding it down turn the key to position "II" (don't start)
3. Continue to hold the reset button down until the service light begins to flash.
That's it - the internet used for good.