I suspect you probably don't have TC on your SE. Look on your spare tire cover for the 'Service Parts Identification' label. If you don't have RPO code NW9, you don't have traction control. You will have ABS, but this is another system entirely and can't be disabled (except as noted by Archon).
There are different systems available on the 2000+ Bonnevilles.
1. ABS - Standard on all cars.
2. Traction Control - Usually not seen until the SLE, but available as a factory option on the SE (if specifically ordered).
3. Stabillitrak - Full stability control system, only available on the SSEi or GXP.
StingRay Bike w/cards in the spokes, Weeeeeee!