How do you turn off the brake wear light on a Lexus ls400?

Answer 1

Replace the worn brake pads. If that has been done, then the warning lamp needs to be reset ... best leave that to an authorized dealer. On a 1998 LS400 (perhaps all other years too), there is a "closed-circuit" wire that is clipped onto the brake pads. It is located and designed in such a way that when there is plenty of pad left, the closed-circuit wire is simply left alone. However, when the pad wears down close to its end, this wire ends up touching the spinning rotor, thus becoming an "open-circuit" and then trips the computer, telling you that you need brake service. This wire, when new pads are inserted, now returns to a closed circuit because it is not touching the rotor. BUT, if you either 1. wait too long to change pads while the warning light is on, or 2. have had multiple brake jobs, THEN this wire will end up rubbing against the rotor and thus break / wear through. With a broken wire, the brake light will remain on, unless you either solder a new piece of similar gauge wire to replace the missing piece, OR purchase a new sensor assembly. I did a simple solder, and it works perfectly, and didn't cost me any $. ALSO, before trying this method, try disconnecting the battery for a minute or two. I don't recall for sure, but it may be possible that the brake light will turn off with this battery reset. If the light still stays on, then try checking the sensor wires on the front wheels. Don't forget it's a good idea to always disconnect the battery before doing any work; especially when performing this type of repair / soldering. I hope this helps you.