It comes on every 5k for turbos and 7.5k miles for non-turbos. For the 96 model, the OBD-II system doesn't allow you to reset the light yourself. If you are very lucky, you may have a dealer that will reset it for some small or no cost. It can only be reset by computer or with a special tool. However, my dealer would only reset my light if I agreed to a $100 oil change and checkup.

You would be fine if you did like I and many other owners of these cars and learn to ignore that light for the two minutes that it is on. My light was only reset one time in the 89k miles that I owned my 96 855T, and that was only right before I unloaded the car before I got stuck with another $2k worth of repairs, after spending $1k in repairs in both September and October last year.

Good luck