Brake Fluid Level Switch
WARNING: This page is about a different car, the 2004 Honda Odyssey and 2003 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.
Remove reservoir cap. Check that float moves up and down freely; if it doesn't, replace reservoir cap assembly. Check for continuity between terminals with float in down position and up position. With the float up, there should be no continuity. With float down, there should be continuity.