One problem related to brake sensor has been reported for the 2002 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Toyota Highlander based on all problems reported for the 2002 Highlander.
Left (driver side) front abs began activating spontaneously as my 02 Toyota Highlander came to stop. Service agency found no code. Removing fuse on abs sensor eliminated 'false activation' problem, but disabled abs; replacing sensor had no effect. Discovered broken sensor ring on rear axle, due to corrosion. (necessary replacement of entire axle) eliminated abs activation on braking, but induced abs activation on acceleration from stop. Replacement of another sensor (also contaminated/damaged by axle corrosion/infiltration) seemed to solve the problem, but I now experience noise/activation when rear wheel drive engages in winter driving. My online research (and service agency) indicate this is a recurring, growing problem in Highlanders and lexuses and other Toyota models sharing the rear axle assemblies, that are prone to infiltration corrosion damage, especially in the northern states.