Harsha De Silva

Steering multifunction keys of volume control suddenly not working in my premio 2011. Only the left side, buttons are not working. Right side buttons are working. I went to a car audio setup person and he told that cotrols in setup is hidden (kenwood). But @ toyota they told that this happens in this premio/allion model and need to reset and asked to book another apointment for it when i serviced the vehicle. Does any one know what has happen / how to reset it?