Here's what is needed to swap your OEM OnStar to a OEM Bluetooth Onstar module.
Bluetooth OnStar Module Part Numbers: 25984444 and 20783877(newer)
YOU CANNOT GET THEM from the dealer, online parts stores, etc.... You have to buy them from an individual(ie..ebay, member classifieds)
If the module does not have the bluetooth antenna attached the part number is 15938939.
You do not have to change your steering wheel controls unless you want to see the phone symbol. They work the same except the newer ones have the phones symbol. If you want to buy the newer steering wheel switches the part number is 25851951. I did not as it was not necessary to work.
Steps to swap the modules:
Remove the trim bezel surrounding the radio, ac controls, and accessory panel. There are 8 or 9 clips that hold it in place. I used a butter knife to pry the trim bezel off. The butter knife is thin enough to go between the trim and the outer console. I pried the trim bezel out enough to slide a long thin flathead screwdriver under it. I slid it approximately half way so the tip was next to one of the clips. Gently apply pressure on the clip, you will think it is going to break, until it pops loose. Go around the bezel until all the clips are loose. Remove the accessory panel, ac controls and radio in that order. There is enough slack in the stock wiring to leave them connected. Just pull them out and move them over to one side. I put the accessory panel and ac controls on the right then the radio on the right. You will see the OnStar module at the bottom of the opening. It is held into place by two clips. One one either side. One on the left and one on the right. I used two long thin flathead screw drivers to hold the clips back off of the OnStar module so I could use both hands to lift the unit out of the retaining bracket. The OnStar module does not have a lot of slack to pull it out while connected. I disconnected it by removing the connector on the right first and then worked my way across the back from right to left until all of the connectors were disconnected. The antenna round antenna connectors are removed by pushing down on the retaining clips and sliding them back.
If you want to retain OnStar functionality it is a good idea to take picture of the label on top of the new module. This will give you the Station ID number and other important information needed to complete the programming.
After I plugged the new OnStar module in I tested everything before putting it all back together.
To access the bluetooth I pressed mute(voice) button and waited of the beep. Then said OnStar. Waited for the system to say OnStar ready then said bluetooth. Waited for the system to say bluetooth ready. You can say help to get a list of options. I chose "Pair" to pair my blackberry. You can follow the voice instructions to complete the pairing to the devices. Good news is that you can pair to multiple devices. If you and your wife or friend are riding together you can pair both phones. If your phone is not available you can tell the system to use the other phone to make the call. Or it your friend wants to call someone using their caller id they can choose to use their phone from the list instead of yours. Pretty cool!
Enabling OnStar functionality. I'll start by saying I have not completed this part of the process yet so I am speculating. I pressed the OnStar button and of course they answered using the wrong name. I told them I performed a hardware swap and needed to update their system with new OnStar module station ID number. They said I had to take it to the dealer first so they could run it through the "TIS2" web program. Then I could call them back to move my service to the new module.
