A follow up to this posting that will help future searchers.
My '98 LS400 has sensors on passenger front and rear rotors. Other years may have them on all 4 wheels.
If you let the pads wear to a point where they wear through the sensor, you can do one of two things. (1) Replace it at $60-$80 per sensor or (2) clip the wire, twist them together or solder them and tape the ends.
Once you close the circuit, the light will immediately do off. No need to reset the ECU or anything.
If the light doesn't go off, check the other axle. I beat my head on a wall for a week trying to get the damn light to go off before it finally dawned on my that (by chance) both my front and rear pads wore out almost simultaneously.
The second I clipped and tied the rear wires, the light went out immediately. I then went on to do a rear break job.
