What my symptoms were, and how I fixed it.. in case it helps others.
I have a 2001 Sequoia Limited 4x4 - My VSC off, and VSC trac lights were stuck on.. so was my emergency brake light (no the e-brake was not engaged) on rare occasions they were off when I started my car, but always came back on.
I took it to the dealer
on Friday, and the diagnosis was: that my rear brakes were bad (less than 10 to 20% left) and this is causing my light problems.. they wanted $280 for the rear brakes. (they also said my fronts had left than 40% left) I declined their offer and elected to repair myself. (I was stuck paying a $47.50 diagnostic fee)
I went to a local auto parts store, and purchased semi-metallic pads for the rear for $40, and cermaic for the front for $40.
I removed the wheels, and replaced the pads. Rotors appeared to be fine.
I had also been reading online on these forums about a speed sensor on the axle that can get metal on the magnets cuasing improper reading and thus giving me the same errors. So I followed the advice, and carefully removed the 10mm bolt, and gently pryed out the sensor on each for the four.. and sure enough 3 of the 4 had some metal or goop stuck on the pickup. I wiped them cleaned, and reinstalled.
So far my lights are off, and my brakes seem to be greatly improved..
So for $85 in parts (2 sets of pads, and 1 can of spray brakecleaner) + the $50 for diagnostic.. I am VERY satisfied how inexpensive this was to correct.
Hope this helps others.