McCheez

Hello all,

well, i bought my first used 2007 IS250 a little over 3 months ago.
you may be seeing several posts from me for help in the future.
The previous owner of my IS was a little rough on her but i didnt mind and would like to polish her up a bit.

so on to my first shout out for help:
So i was driving around on Friday March 12th, had my ipod plugged into the audio input and listening to music. Suddenly the sound cut out.
I switched to radio, to cd, back to the auxiliary and still no sound.
I tried to turn the volume **** and also tried the volume buttons on the steering wheel but no VOLUME shows up on the radio screen. I tried shutting the car off and turn it back on...still nothing. I cant even change the bass or treble or anything. the radio is working but just no sound from any speaker.
I checked the fuses under the hood and the passenger side. both fuses are good. one of them has the prongs a little "burnt" so to say, but nothing blown out. I managed to take part of the center console out but thats it.
So i dont know what to do now.
Does anyone know what it may be?
and also
Does anyone know how to remove the radio to check for any loose wires or fried circuit or something, if need be?

Sorry if the post is long.

Thanks,

Slammer1

I'm not sure what your problem is, but can almost guarantee you it isn't a loose wire. There are four harnesses that plug into the back of the "radio". Three in the cd changer, and one for the display itself. These are quite hard to unplug, and the odds of a loose wire being the culprit are pretty much nill. If your are certain that there aren't any blown fuses, I would be more inclined to think that the problem is either in your amplifier in the trunk, or the cd changer (below the display) itself.

McCheez

funny thing happened this morning....speakers started working again.
now im waiting for this crap to happen again.

joeker

iTrader: (8)

was your ipod's volume turned up?

McCheez

lol yea it was. i didnt get sound from radio or cd player either.

.....and my speakers stopped working again.
this is really frustrating.
How will i know for sure what the exact problem is?

Lilblue

It could be your factory amp that cutting in & out .... Lexus know for having bad factory amps.

McCheez

la ching@d@....

well this amp, essentially its just to amplify the signal from the radio/stereo am i correct?

how would the lack of volume display and the rest of the sound settings be affected if the amp was the one not functioning....unless the radio doesnt "detect" the amp and therefore no settings are displayed or able to be changed. or does the actual head unit control all of that no matter if an amp is present or not.

i dont mean to question anyone's response, just thinking out loud and trying to make sense of how this thing works. Hoping we can pinpoint the exact cause of this by using everyones input and knowledge....lol dam that sounded corny.

sorry if i sound like a noob.

I appreciate all of your responses and help.

Slammer1

You don't sound like a "noob" at all, in fact you pose better questions than most. The audio in the IS is quite complicated. The stereo consists of the display, the cd changer, and the amplifier. You do not have normal signals going to the amp from the radio, but rather just a couple of signals. There are also data lines going to the amp, and it is at the amplifier that all of the volume, tuning (treble, bass, etc) are handled. From the amp, the signal is then sent out to the speakers. Now for the bigger issue, there are two body control modules (one in each kick panel), which monitor and control the function of the audio system. If you are familiar with pulling check engine light codes on a car, to find out what sensor or component has malfunctioned, this system works the same way. I have seen repair manuals, which show a series of buttons to push on the HU, which will basically retrieve the DTCs (diagnostic trouble codes) for the audio system itself. I will have to dig around for them, but this may be something worth trying.
I really don't think you would have lost your display information if the problem was just in the amp, but to be honest, body control modules rarely fail, at least not within the first ten to fifteen years of use.

Slammer1

I am still looking, but this could be a possibility.......



Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier

DESCRIPTION

This circuit sends a signal to the stereo component amplifier to mute noise. Because of that, the noise produced by changing the sound source ceases. If there is an open in the circuit, noise can be heard from the speakers when changing the sound source.

If there is a short in the circuit, even though the stereo component amplifier is normal, no sound, or only an extremely small sound, can be produced.

Slammer1

The flowchart for checking components that would give you a "no sound" symptom is as follows:

1. AVC-LAN circuit
2. Radio receiver power source circuit
3. Integration control & panel assembly power source circuit
4. Stereo component amplifier power source circuit
5. Sound signal between radio receiver and stereo component amplifier
6. Speaker circuit
7. Mute signal circuit between radio receiver and stereo component amplifier
8. Stereo component amplifier
9. Radio receiver
10. Integration control & panel assembly


If you took it to a dealer with the "no sound" symptom, this is likely the order that they would go in to determine which signal or component was faulty. By no means is this an easy diagnosis, as you have to pull the connectors for these circuits and measure voltage and resistance with a multi-meter. The amplifier isn't hard to get to, but having to pull the display and cd changer assembly is tough.
You really may want to check with the dealer on what they would charge to determine where the issue is.

McCheez

wow thanks!!

well, i got an update....
went to the dealer and they said that they dont know what it could be and it would cost $120 to take the head unit out and replace it.

also, my speakers randomly start working some times.
so far ive kept my ipod plugged in to the auxiliary port...ive noticed that the ASL indicator turns off and all my settings reset and the sound cuts out....returning after a couple of seconds. so far its only happened with the ipod plugged in. havent noticed it yet with the radio.
when the speakers dont work when i turn the car on, i keep turning the radio on and off and they start working after several tries, well that happened today. dont know if that will work everytime.

i found another post with similar problems but with an older vehicle:
https://www.clublexus.com/forums/ls4...-levinson.html

McCheez

i noticed lastnight and this morning, popping coming from the speakers, right before the speakers start working again.
and then i would hear it again while they work, right before they cut out again.

this is really frustrating.
i wanna punch the audio system with a speeding train.