One problem related to speed control cable has been reported for the 2001 Lexus RX300. The most recently reported issues are listed below.
The contact owns a 2001 Lexus Rx300. While driving 80 mph with the cruise control engaged, then the vehicle accelerate on its own. She attempted to turn the cruise control off; however, after engaging the brakes the vehicle failed to stop and accelerated up to 100 mph. The contact was forced to exit at an off ramp, down shift into park in order to stop the vehicle. The dealer stated that the throttle cable was stuck and frayed; however, he also stated that the cable exhibited normal wear and tear. The failure mileage was 80,000.