Weird sound system problem
 

Yesterday I got in the car to go grab some lunch. Using the mode button on the steering wheel I tried to flip over to an AM station. No sound. There was sound when I turned it back to FM. I have an MP3 CD loaded and that worked as well. Nothing was plugged into the Aux jack and my Blackberry was wirelessly connected via Bluetooth. It appeared the AM tuner was working since I could hit the scan button and frequency would stop on all the normal stations, but still no output. Then I started playing around with the local controls and got AM output by pressing the AM button on the dash unit. I went back to the steering wheel mode button and everything seemed to be back to normal. A little while later my wife called my Blackberry. Our home number showed up on the display but there was nothing from the speakers, when it should have been ringing. I hit the off-hook button on the steering wheel and still nothing. My wife could hear me but I could not hear her. I disconnected and disabled the Bluetooth connection, called my wife back, and finished our conversation. Next I reenabled the Bluetooth connection and called my wife back. This time I could hear the phone ring and she could hear me talk after she answered.

I have a hunch the whole issue had to do with the Bluetooth connection (I've had some minor connection issues with it before) but how it effected the AM output is strange. I'm not taking it to the dealer (yet) but I'd be curious if anyone else has had a similar problem.

Re: Weird sound system problem
 

I had the same type of problem and at the time I hadn't even tested the Bluetooth feature or used the aux plug of the car yet..

My issue was I tried to go from CD to FM using the dashboard button and I got no sound (the frequency seemed to be tuned in ok). I'd change to different stations.. still no sound. I went to AM.. no sound.. then back to FM.. again no sound. After flipping back and forth a few times the sound seemed to kick in and all was well after that.

Re: Weird sound system problem
 

I've had exactly the same thing happen to me. (It's happened to others on this site as well...search "AM Mode Silent") Luckily, it once happened on the way to the dealer, and I was able to show him the problem. At first, they said there was not a TSB issued and they would not work on it until one was issued. Eventually, they claimed a TSB was issued (although I was not able to find the actual TSB) and they agreed to replace the radio. The day after the new radio was installed, the same problem occurred. That was about two months ago. It had been happening about once a week, but now it's almost every day. FM goes into silent mode every once in a while now, too. Since my commute is about an hour each way, it makes it difficult (impossible) to use the bluetooth.

Since the dealer was not much help, I checked the Toyota service manual on AV systems. (I wasn't able to upload the document for you.) It appears it is caused by a short at the amplifier under the passenger seat. When this occurs, it will not send output to the speakers. Next step is to find a dealer who is familiar with electrical issues.

Re: Weird sound system problem
 

my car still has this problem even after the amp was replaced and the radio twice, exact same symptoms. It happens rather rarely though. I have had numerous warranty issue with my car so it is annoying though.

Re: Weird sound system problem
 

I just found this post, and I am having the same problem as well. Just today, I turned on my radio and there was no sound at all, and the station that it was set on should have been received perfectly clear. I switched to the next FM band and no sound. I switched to AM and there was no sound. I even turned off the radio and turned it on again, and still no sound. I played a CD and was able to get sound instantly. Once I switched to the radio, it seemed to work. I'm also having problems with the sound system not being able to read a CD that I know should be readable. Other times, the CD player has difficulty starting up. Do these issues require having the dealer install a new CD changer and radio?