Expert: Cleggsan - 12/3/2009

Question
I have a 2006 Toyota Camry Solara Convertible.  The volume adjusts on its own all the time. There is a feature that the volume is supposed to adjust with your speed when the top is down.  However, now the volume just adjusts at any given time and now it is doing it all the time.  Is this sensor in the audio system or on the vehicle?  Also, the stereo is the factory installed navigation system as well.

Answer
You should be able to defeat the auto level control. When that feature is on the volume is adjusted according to the speed of the automobile which is taken from the speedometer system  (at least it is in most cars; however some of them adjust from the level of acoustic noise inside the cabin via a microphone which is used to monitor the sound pressure level) and the whole thing is pretty simple in concept but complicated in its execution.

If you defeat the level control does it still seek?   You might test its function with it both OFF and ON and with the top down and again with top up.

If it is not controllable and you are convinced it is an electronic defect within the head unit I suggest you take it to an install/repair shop that specializes in Toyota cars.  Do not take it to the car dealer unless they have an audio specialist on staff (very  few of them do).

The audio volume level is adjusted electronically and it may have a bad IC or sensor.

Hope this helps.