Rear brake sensor?
This was from another forum:
"It wont go away by itself.
Try this:
1. with engine running
2. press and hold odometer
3. service light will appear (yellow triangle)
4. while still pressing odometer press the BC button on the turn signal stalk
5. navigate to desired reset function such as brakes by pressing the BC button
6. to reset, press and hold BC button
7. a rotating hand of a clock will appear
8. press BC button again and a check mark in a box will appear
9. turn off/on engine to confirm that indicator light has been reset.
If it wont work, at step 6 try a double press instead of holding it."