Here is what the problem is, one or both of the rear wheel speed sensors are shorted. they are integrated into the rear bearing hub assembly. You may obtain the entire assembly on E-bay for about $ 35.00. You can find out which one by an OBD2 reader that will read the ABS failure code. After replacing the bad assembly, you must reset the ABS computer not the ECM computer. DO NOT attempt this repair unless you have an air chisel to break the rusted assembly free from the backing plate. The rear caliper, pads and rotor must be removed to get to the bearing hub along with the emergency shoes. There are 4 bolts that hold the hub to the backing plate/ steering knuckle. The front sensors should be removed and cleaned with alcohol. Also shop air to blow the crud off the tone rings on the CV joints thru the sensor port. Dirt gets in between the tone ring grooves and causes the front sensors to hiccup. So for about 35.00 you can do the entire job yourself and save over 600.00 dollars. How do I know this is it, Been there done that on my 2002 Highlander with 240,000 miles. Good luck man it's about a 3 hour job with proper air tools.
