2009 Toyota Corolla Owners Manual - Page 189

3-2. Using the audio system n Adjusting the Automatic Sound Levelizer (ASL) Except JBL brand audio system When "ASL" is selected, turning to the right changes the "ASL" level in the order of "LOW", "MID" and "HIGH". Turning to the left turns "ASL" off. ASL automatically adjusts the volume and tone quality according to vehicle speed. JBL brand audio system When "ASL" is selected, turning and turning to the right turns "ASL" on, 3 Interior features to the left turns "ASL" off. ASL automatically adjusts the volume and tone quality according to vehicle speed. 223