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Discussion Starter #1
Does anyone have any idea where the Bluetooth antenna is in the early 2012 (non-Mylink) Volts?

I looked at the diagrams gmpartsdirect has posted, which indicated that it is directly attached to the back of the VCIM (Onstar module), but it’s not actually there. Presumably it’s remotely mounted somewhere else.

I have a DTC set for a Bluetooth antenna short to ground. It’s causing a red Onstar status light, though the Bluetooth seems to work fine.
 

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Service information is showing the sensor connected to the back of the VCIM to the center coax cable style connector (if equipped) . The DTC you likely had was likely B2485 02 Short to Ground. If antenna was missing I suspect your DTC would have been B2485 04 Open/High Resistance.

Short to ground DTCs also set when their is a lack of power. The next step I would take is to confirm the 12 Volt battery in the trunk test good, Has your 12 volt battery been replace yet? Can you clear the DTC?
 

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Below is a pic of what my VCIM looks like. That's not actually mine, but an ebay pic of a the same part number (22842168). As can be seen, there is only one antenna connector (it's either the GPS or cell antenna). And, it has a lead connected to it, not a Bluetooth antenna module. So, the Bluetooth antenna must be somewhere else in the car.

Yes, I'm getting a short to ground DTC. If I clear the DTC with GDS2 is immediately reappears. 12V battery is only about 18 months old and shows normal voltage.
 

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Bluetooth range is not very far. I am only spit-balling here but the BT antenna is probably only about an inch long and may in fact be on the circuit board and not an external antenna.
 

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Discussion Starter #5
Bluetooth range is not very far. I am only spit-balling here but the BT antenna is probably only about an inch long and may in fact be on the circuit board and not an external antenna.

That is possible. Though it would have a been foolish to encase the antenna inside a metal housing.

This is what the Bluetooth antenna is supposed to look like (glad I only spent $7 on it).

http://a.co/gYmsDRx

I wonder if I can find an app that will let me track down the Bluetooth signal with my phone or laptop.
 

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Some of the radios had the Bluetooth antenna plugged into the back of the radio. My 2014 has the Bluetooth antenna built into the radio.
 

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Discussion Starter #7
Some of the radios had the Bluetooth antenna plugged into the back of the radio. My 2014 has the Bluetooth antenna built into the radio.


The Mylink Radios have the Bluetooth module built-in. That's how they're able to stream music via Bluetooth, while the non-Mylink systems are limited to Bluetooth phone calls.
 

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Per GM SI for a 2012 Volt, "The Bluetooth ® hardware is internal to the radio. The radio supports streaming of data (music, voice, information) from cellular phones and other mobile devices that support those features. The radio may also be capable of interfacing with cellular phones for hands-free features." So, according to GM, if the antenna isn't on the back of the VCIM, it's built into the radio.
 

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The Mylink Radios have the Bluetooth module built-in. That's how they're able to stream music via Bluetooth, while the non-Mylink systems are limited to Bluetooth phone calls.
That's got nothing to do with the antenna and everything to do with the development of the A2DP bluetooth profile, which didn't really settle down and have a standard until around 2010/version 1.3. Basic function was available earlier but it was kind of .. you got audio and a lot of vendor-specific extensions to do everything else, like pause or show track info, etc. 1.3 standardized a lot of that stuff.
 

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2011 SI.
"The Bluetooth ® antenna is a small fixed antenna connected directly to the telematics communication interface module and is used to send and receive signals from a Bluetooth ® enabled cellular phone. The antenna utilizes no cabling and is not external to the vehicle. The available features and functions are determined by the software within the device being used and the telematics communication interface module."
 

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volt1.jpg volt2.jpg

This is from my 2013, but maybe 2012 has a similar design? Looks to me like the front silver "bars" are the bluetooth antennas. So in a way they are contained within the radio, just attached to the outside front. Pre-mylink might be totally different though, in which case it's probably part of the onstar module.
 

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Discussion Starter #12
That's got nothing to do with the antenna and everything to do with the development of the A2DP bluetooth profile, which didn't really settle down and have a standard until around 2010/version 1.3. Basic function was available earlier but it was kind of .. you got audio and a lot of vendor-specific extensions to do everything else, like pause or show track info, etc. 1.3 standardized a lot of that stuff.


It has to do with where the antenna & Bluetooth control functionality reside.


In the non-Mylink cars the VCIM (OnStar module) handled all Bluetooth functionality and has the antenna connected to it in some fashion. In the case of my VCIM, it appears that antenna is remotely mounted somewhere.


Once Bluetooth music streaming became possible (Mylink radios), Bluetooth functionality was moved to the radio, along with the antenna.


I'd kill for a detailed & accurate wiring diagram of the entire car.
 

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Discussion Starter #13
Per GM SI for a 2012 Volt, "The Bluetooth ® hardware is internal to the radio. The radio supports streaming of data (music, voice, information) from cellular phones and other mobile devices that support those features. The radio may also be capable of interfacing with cellular phones for hands-free features." So, according to GM, if the antenna isn't on the back of the VCIM, it's built into the radio.

That's the later 2012s that had Mylink Radios. No Bluetooth audio streaming for me...
 

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Discussion Starter #14
2011 SI.
"The Bluetooth ® antenna is a small fixed antenna connected directly to the telematics communication interface module and is used to send and receive signals from a Bluetooth ® enabled cellular phone. The antenna utilizes no cabling and is not external to the vehicle. The available features and functions are determined by the software within the device being used and the telematics communication interface module."


That's what all the docs I can find say, but it's not actually that way. The picture of my model VCIM shows it only has the one antenna connector that for either GPS or Cell.
 

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Discussion Starter #15
View attachment 144513 View attachment 144521

This is from my 2013, but maybe 2012 has a similar design? Looks to me like the front silver "bars" are the bluetooth antennas. So in a way they are contained within the radio, just attached to the outside front. Pre-mylink might be totally different though, in which case it's probably part of the onstar module.


Pre-Mylink was completely different since the VCIM, not the radio, handles Bluetooth. Maybe mine is some weird hybrid since Mylink was introduced shortly thereafter.
 

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That's what all the docs I can find say, but it's not actually that way. The picture of my model VCIM shows it only has the one antenna connector that for either GPS or Cell.
Can you find a picture of the front of your VCIM? The antenna might be poking out there like in my radio pics.
 

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Discussion Starter #17
Can you find a picture of the front of your VCIM? The antenna might be poking out there like in my radio pics.


I pulled my actual VCIM out of its mount and looked all around it. It has two brown wiring harness connectors, one white wiring harness connector (unused), and the GPS/Cell Antenna connector. Nothing else anywhere on it.
 

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What's the P/N on your VCIM?
 
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