Hey guys,

I know tons of people have had issues with their amps on these and the IS forum. My issue started off as maybe once every 5 months or so I’d start the car and the audio wouldn’t work. I’d hold down the radio on/off button and the system would reset, and audio would restore. Then it became more frequent, and now it’s at the point where it doesn’t play sound at all. Neither from the volume on the radio nor the steering wheel.

I took out my amp, visually inspected it and found corrosion, so like common sense I sent it off to be repaired, only for the sound to not work when it was returned. Repair tech was adamant it is fixed. And looking inside it looks like he did a great job. I even made a little basket to prevent the water from reaching the unit incase it leaks in again (after sealing the vent with duct tape). I read about some instructions to clean all electrical connections with electronics cleaner including the one that’s underneath the center console. Still nothing. Has anyone had any issues with their factory radio (P10082 model)? Amp is good, wiring looks good, fuses are good, so I’m kinda baffled

 

Not sure if i have the same kinda issue as you or one of a similar involving the same components. My AM/FM seems to only work in the morning when i first start the car and will keep working if i leave it on that station the entire time. But if i try and turn the station or switch to media then go back to AM/FM it stops putting sound out and the station display flashes randomly like a weak signal. All other media sources work with sound except AM/FM, but do when the whole system is cooled down in the morning. Any thoughts?

 

That’s definitely weird, I’d say probably either the head unit or the antenna which would suck to replace.

 

I wonder if there might be a break in your antenna in the rear glass. Do you have tint covering the rear? If not you might be able to check continuity of different sections of the antenna. I'm not sure how much glass expands with heat, but that area gets pretty hot in the sun.

Just a thought. Not sure why it'd stop working (even when cool) when you switch stations or audio input.

 

Just to update, it’s not the radio, and most likely not the speakers either. They ohmed out good. Anyone?

 

Only other thing to check would be Pin2 of the big, 30 pin amp connector. It should be a white wire. It is the mute signal. If you measure it in relation to body ground, it should be above 3.5V when system is unmuted, and less than 1V when system is muted (when you get an emergency call).

Pin 1 - Green - battery voltage
Pin 2 - white - mute
Pin 3 - white/black - ground

First check it with the connector unplugged, to make sure you are getting above 3.5V when you are expecting audio to be played. If you are not, then you'd ha be to see if there is a short to ground somewhere, or possibly the telematics transceiver is bad.

If you are getting above 3.5v, then plug the connector in. Try to measure it from behind the connector. This is to make sure something within the amp is not being ing this signal down to under 1v, which would trigger a mute signal.
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Thank you! I am not getting any voltage to Pin 2 when disconnected and powered on. I tested the buttons in the hidden menu system and both steering wheel and volume button are registering.

What is the telematics transceiver?

 

Just to verify, make sure to measure the other 3 pins listed to make sure your multimeter is actually able to make good contact with the pins. This is to sure that 0V you may be getting on Pin 2 is actually 0 and not just a misread.
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With the amp 30 pin connector disconnected measure the following:
​​​​​Measure continuity between pin 3 and body ground. And measure voltage between pin 1 and body ground.

If above pass, measure continuity between pin 2 and body ground (or pin 3) to make sure there isn't any short to ground that might be bringing the voltage to 0V.

The telematics transceiver, I'm not 100% sure. I think it's for the SOS system in the car. Among other things, it'll send a mute signal to the amp when there is an emergency call going on. It's located in the dash, above the glovebox compartment.

Ideally, you'd get to the transceiver and disconnect the connector and measure voltage directly at the mute pin to determine state of the transceiver. But trying to work around that for now since it seems like have to remove the glovebox door to get access to it.
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Yeah I just took it down, disassembled it and the board looks clean and in good condition. Upon plugging it back in, it made some weird noise. I guess I could part swap it and see, but this is doubtful. Frustrating.

Oh, and pin 2 definitely had zero volts going through it, it made good contact. Thanks for your help by the way.

 

Alright, just to check it's not shorting to ground, check continuity between pin 2 and pin 3 (or Pin 2 and body ground). It should measure with more than 10k ohm. This is for the same 30 pin connector going into the amp.

Do this with the connector disconnected from the amp.

 

Just to update. It is a bad amp. Found a buddy who let me swap his out and it works. Goes to say, just because it’s refurbished or fixed doesn’t mean it actually is. For anyone having the same issue, make sure you put a known good amp in before taking everything else apart lol

 

Just FYI: To help others for this problem. Just about each and every thread that has this problem with the system playing. It's just about 99.9% of the time the Amp. Trouble shooting the whole system before knowing the amp is not bad tends to lead right back to the amp. Especially when you can see evidence of water moisture. The amp can also damage back to the head unit by shorting it out also. When all of the speakers are the same result (not playing) that's normally the key to it.

I have not had any moisture nor water in my trunk amp area at all, but I made a plastic cover over my amp to prevent water just in case. Preventing this problem is the best action knowing that this can happen.

 

Yea that was my thought too, especially with the actual corrosion. But figured we'd go down the diagnostic tree since it had been "repaired" already. I'm guessing this repair service didn't have a GS laying around to test it before shipping out lol.

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I thought the panel beater may not have attached antenna properly, but then the USB and DVD were not working either - so it turned out to be a common fault with the Pioneer head unit, and Lexus has a head unit exchange program for $500. Go to local Lexus dealer.