I had a a similar problem. All the warning lights came on. Screaming sound from the brake system. The Lexus dealer said it was to do with the dot 3 brake fluid. Dot 4?? I think is the replacement. I had a major service and they had used the upgraded dot 4 fluid. This was replaced and problem over. The master cylinder and brake system are in one piece and cost about $5000 to replace....ouch!! I have had no problems since. I know I can buy cheaper parts via my family in Japan....my wife is Japanese.