within past 2 days the red "brake" warning light & yellow "trac" light have been coming on. Brakes work fine, Traction control is not working. Owners manual, of course, says take it to a Lexus dealership immediately. However, I have been told that you usually enter the service dept, bent over, and walking backwards for your wallet cleansing (hopefully that is all you will get ). Does anyone have experience or ideas..... am I looking at a bad relay??? Any help is greatly appreciated... from frozed Michigan. Marcus:

 

Just a guess, but your park brake (remember, it's a drum) could be seizing/freezing. Suggest you engage and release your park brake several times (at a stop!) once the car is warm.

 

Thanks for the advise... you may be on to something... it has been freezing and thawing a lot up here over the past week. I will give it a try after the car is warmed up. I have only owned the gs3 for 2 months. I has no idea that the center of the rotor was a miniature drum !!!!

 

I've only ever heard of cars using drums as parking brakes. Perhaps it has something to do with being a redundant system from the main braking setup.

Park brakes can be a pain - they NEED to be used once in a while at least.

 

It finally warmed up here in michigan. I pulled the rear wheels and did a visual inspection, everything seemed fine although emergency brake lining very thin. I then pulled all relays that were associated with "abs" or "trac". I carefully took the relays apart and cleaned the contacts with strips of construction paper, several were dirty! Started the car, warning lights still came on. I did a visual check under the hood and noticed that behind the passenger side strut housing there is an aluminum-colored block with steel lines going into it. It has a little tray under it and it had some brake fluid in it. I assume it is part of the abs system. The fittings going into the top of this block were wet with brake fluid!I sprayed the entire top with carb cleaner and then carefully tried to tighten the fittings, 2 of then did tighten a small amount. I then saw under a red rubber fitting protector that there was a fluid release fitting. I cracked the fitting and brake fluid shot across the garage and hit the opposite wall! (I am glad I was in the clear!) I tightened the fitting back up and started the car. Guess what? The warning lights went off! I am assuming that maybe there was air trapped inside. So far, everything back to normal. Mark

 

That's pretty wild! Glad it solved the problem. Hopefully your brakes still WORK! :eek:

 

My parking brake light often lights at start-up. A light pull on the release handle always turns it off. I suspect a sensor switch that's too close to the edge.

One reason parking brakes are drum is because they have 'self-energization' ... as the drum tries to rotate, it increases the force of the shoe against the drum. Disc brakes don't have this. Therefore, it would take either huge force by the driver, or very long travel of the pedal.

The lack of self-energization is the main reason disc brakes are much more stable than drums. With a drum, a slight change in friction (water, temperature, contaminents) is multiplied.

I must have too much time on my hands.

 

I used to have this issue. It was caused by me accidentally hitting the park brake pedal with my left foot getting in or out of the car. I guess I've learned not to now.

 

Hmmm. Maybe so. I'll pay closer attention.

 

OK, looks like life is one step at a time.... the brake warning light no longer comes on, but now, the trac light is coming on again. It is not on all the time. During the times when it is not on, the traction control seems to work as when I break the wheels loose, the trac light flashes on and off, which is the normal operation, to my understanding. Any words of wisdon out there????

 

marcus - still might be a rear seized brake caliper (happened on my old Acura) or a bad speed sensor.

 

Thanks for the advise. I will try to see if there is a way to test a speed sensor... Maybe an ohm meter will reveal something if I check both sensors. I did see these sensors on the rear wheels when I pulled them recently. I assume they must pick up a magnetic field signal.

 

Bit: You're right on. It happened yesterday. I looked closely at the parking brake pedal when I pulled the release. Sure enough, it popped up about an inch. Thanks.

 

You're welcome.