Had this problem for over a year now.. seems to go away during cold months. And is very noticeable during warmer seasons.

It's a very high pitched whiney, crackling noise that comes from the front right area of the cabin. At first thought you think it's the speaker, I've replaced the speaker, no change.

One odd ball thing is if I press the power button on the onstar module it will turn the noise off but then it starts right back up again, soooo annoying. I'm planning to rip apart the dash and disconnect the navi, onstar and then go from there.

I got a video of it.... anyone seen this before? I've been searching for answers for awhile now and had no luck

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TECHNICAL

Bulletin No.: 07-08-46-002D

Date: July 29, 2009

Subject: Audio Whine Noise from Radio Speakers When Using OnStar(R) (Install Noise Suppression Filter)
Models:
2007-2010 GM Passenger Cars and Trucks (Including Saturn)
2007-2010 HUMMER H2, H3
2007-2009 Saab 9-7X
Equipped with OnStar(R) (RPO UE1)

Supercede:
This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 07-08-46-002C (Section 08 - Body and Accessories).

Condition

Some customers may comment on an audio whine coming from the radio speakers when using the OnStar(R) system. The amplitude and frequency of the whine will change with an increase or decrease in engine speed.

Cause

This condition may be caused by electrical noise on the OnStar(R) Vehicle Communication Interface Module (VCIM) battery feed wire being passed to the microphone output pins at the radio.

Correction

Technicians are to install a noise suppression filter, P/N 1224205, into the OnStar(R) battery voltage circuit, a few centimeters (inches) from the VCIM. The filter package has three attached wires - a single yellow wire at one end with a yellow wire and a black wire at the other. Install the single yellow wire side into the battery voltage circuit towards the VCIM. Install the remaining single yellow wire into the battery voltage circuit toward the fuse and the black wire to ground.



Important

The noise suppression filter is polarity sensitive. The filter is designed to be most effective when the end with the capacitor ground is connected towards the source of the electrical noise. Install the filter in this polarity first. If the noise level is still not satisfactory, try disconnecting the capacitor ground. In some cases, if the first installation does not correct the noise, try reversing the filter polarity (removing the filter, turning it end for end and then reinstalling it) and grounding the capacitor lead.

 

thank you so much!!!!!!!!!!

 

Damn Fyr... you beat me to it :-)

 

I got files and files of H2 stuff, so when I see a question that I can find, I just click over and copy it in.

 

Def alternator noise caused by a bad or floating ground. I don't think it's related to the tech bulletin posted though because it mentions the vcim on the mic being the cause, you aren't using the mic when onstar isn't on and you say it goes aaway when you turn the onstar on. So what kind of radio is it?

 

Well I thought I was in the clear but I heard the noise again today....
I have the Onstar module completely disconnected but I did keep it mounted in the bay for looks.

I can't believe this.... what else could it be??!

My navigation unit is a Pioneer.

I replaced the alternator early this year, but the noise has been doing it before and after.

 

It is alternator whine caused by ground loop isolation. If it was happening both with and without onstar active I would point to the amp. Because it seems to abstain when onstar is active, I point to the head unit itself. Some simple things to try are relocating the head units ground wire or running a cable from the common on the line outs to the chassis. If everything is wired correctly it could be an issue with the head unit itself and since you don't seem to have much knowledge in this area I would recommend taking it to a customs shop and ask if they have any engineers.

 

Thanks... I think I'm going to completely disconnect the navigation unit and see if the noise returns. If it does, I can rule out the headunit.

 

Fixed it!

As i was taking out the navigation it stopped immediately.. moved it back and forth and it would turn on or turn off so I knew it was some crossed wires or something. It's really tight quarters so I couldn't identify exactly which wire was causing an issue but I was able to spread everything out enough so when I put it back together the noise was gone! Hooray