2010 Toyota 4Runner Owners Manual - Page 380
2010 Toyota 4Runner Manual
Page 380 highlights
3-2. Using the audio system Type B and C STEP 1 STEP 2 STEP 3 STEP 4 Press Press Press . (MORE). (ASL). (type B Press , , (type B only) or only) as corresponds to the desired mode. Type B: "LOW", "MID", "HIGH", or "OFF" Type C: "ON" or "OFF" ASL automatically adjusts the volume and tone quality according to vehicle speed.