The 2000's don't have fluid level monitors, so low fluid can't be the blinking light source.
Likely possibility: Check/clean the ABS sensors -- accumulated dirt will interfere with their ability to generate the pulse signals the ABS system needs.
Next: The low battery is a common source of the lights. If the battery isn't too weak,one way to confirm this as the source of the problem is to start (getting the blinking lights), ride for a couple minutes, then restart the bike (even better, kill the engine when you're rolling (in a safe place!), and bump start it. If the lights are gone, it's the battery getting weak.
Other possibilities:
If one wheel is rotated with the other stationary while the ignition is on, the system will throw a code.
A damaged or disconnected sensor wire can also cause the problem. If your speedo is intermittent and the cruise won't stay engaged, the rear sensor wire may be chaffed at the swingarm fitting where it is ziptied to the rear brake hose.
Report back on what you find -- we can speculate all day with more clues
