I just bought a used Chevy Impala 2005 and it has a microphone placed at the rear view mirror and its wire goes inside the hood. I don't know where it goes and I have no idea how to find its purpose. What should I do to figure it out?

  • Welcome! Thanks for the question. I'd guess that this is a mic for a hands free phone system. Somewhere there will be either a Bluetooth or a cable connection for the phone (assuming I'm right).
    – dlu
    Nov 20, 2016 at 1:25
  • @dlu How do I check if that works or not? Nov 20, 2016 at 3:41
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    From what @tlhIngan says it sounds like it might be for the OnStar system. I've only seen it work once, the controls were integrated with the radio, and maybe the steering wheel. I'd guess it would be in the owner manual. Did you get one with the car?
    – dlu
    Nov 20, 2016 at 4:15
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    Do try to find where the other end of that wire goes. There aren't any good places for it to go under the hood.
    – tlhIngan
    Nov 20, 2016 at 23:40

2 Answers 2


GM vehicles often came standard with OnStar, GM's roadside assistance system. 2005 may be a little early for factory-installed Bluetooth.

  • How do I check if that works or not? Nov 20, 2016 at 3:40
  • OnStar is a subscription-based service. I'd check with a GM dealership or with OnStar themselves.
    – tlhIngan
    Nov 20, 2016 at 3:53
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    Because it's a 2005, you may need an adapter for modern cell networks --> en.wikipedia.org/wiki/OnStar#History
    – tlhIngan
    Nov 20, 2016 at 3:57
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    @SulavTimsina - Just press the blue OnStar button. If it works, it will join with the network and you'll hear the OnStar operator. Just tell them you are testing your system, thank them for their time, and press the blue button again. They will thank you and by this you'll know if the microphone is working, which it more than likely will be. tlhingan is correct about the adapter ... the vehicle needs the newer digital equipment in order to work. Nov 20, 2016 at 12:33
  • @Pᴀᴜʟsᴛᴇʀ2 There is no blue button there. There is only a mic placed just above the mirror; looks like it didn't come originally with the car, may be its past owner has put it there. Thats why I am not being able to find about it. Nov 20, 2016 at 20:02

Impala active noise cancellation began in 2014 model year, so it's OnStar or an aftermarket phone system (which need not be BlueTooth).


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