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217K views 392 replies 93 participants last post by  Bucketokarma 
#1 ·
I purchased my 2008 CTS at the end of October and while it did not have Bluetooth, it had all the other options I was looking for.

My 2008 was manufactured in March 08 and therefore has Gen 7 OnStar hardware.

I wanted to see if it was possible to add Bluetooth to the vehicle, without using aftermarket parts. I figured if I wasn't able to do it through the OnStar module, I'd buy a hands-free visor-mount Bluetooth speakerphone instead.

I bought a salvaged unit off eBay for $65 that came from a 2009 CTS. I found the device from Nordstrom's Automotive and is identified by
CADILLAC CTS 2009 Communication; (OnStar, opt UE1), w/voice recognition (opt UPF).
The model # is 25990227.

Before purchasing, I obtained a copy of the service manual and found that there weren’t any wiring changes that could cause a short or irreparable damage to both the module and my vehicle. I figured if the gen 8 module didn't work, I'd probably could plug the gen 7 module back in without problems.

I know that there was information about the new Bluetooth wiring provisions (WXS) when the Gen 8 Module was introduced. My guess is these wires were already part of the existing Nav system wiring (UQA, UQS), and were just separated into a separate wiring scheme in 2009 vehicles to allow Non-Nav cars to support Bluetooth as well (However, my guess is non-Nav cars might have this wiring too as OnStar runs through the stereo..... just don't take my word for it.) They provide a "Remote Playback Device Left Audio Signal", Mute, Ground and a "Cellular Microphone Signal" to the Nav System.
As mentioned, either my car already has it, or it's not needed as my Nav mutes when a call comes in, and I can hear the caller (and they can hear me) clearly when using Bluetooth.


The device arrived on Friday looks almost identical to the Gen 7 module. The only difference is it has a Bluetooth Connector / Antenna, as well as a Bluetooth logo and MAC address on the label.
Took me about an hour to remove the back seat, interior trim and rear shelf (as well as disable the airbags). At this point I had access to the module. I plugged the new one and turned on the car. Success! I went into the Hands-Free menu and said “Bluetooth” and it recognized it! I paired my phone and was able to make calls through the stereo. At this point my OnStar light was red, but probably because the device wasn’t connected long enough to get an OnStar and GPS signal.

Unfortunately, it took me 4 HOURS to remove the old module. Why? The old module is mounted to a plate and when I tried to loosen the nut holding down the module, the bolt turned as well.

I was unable to remove the tray as it was bolted down and one of the bolts had cap on it that couldn’t be removed (it had a wiring harness running through it, so I was unable to unscrew it).

I had to resort to taping a wrench to a paint stick and sliding it under the try to grab hold of the bolt. (There is a hole almost underneath the module in the trunk; however it was not large enough to place an object in to prevent the bolt from turning).

Anyways, although it took over 5 hours to do, I’m happy that it was successful. I will admit though I’m not sure if it’s a 100% success as there were a few problems that I outlined below:

Quirks

After installing the module and getting it mounted in the back of my vehicle, I turned my car onto accessory mode to verify the module worked before putting the car back together.
  • While the car was on accessory mode, my dash and Nav "restarted" and the DIC came up with the message "Stabilitrack Off". This is a total guess, but I wonder if it was due to the car detecting the new module, OR the battery was almost dead as I was in/out of the car for over 6 hours without starting it. To be safe I charged the battery overnight and it hasn't happened since.
  • Also, on Sunday morning, my NAV display came up with the error that "the display unit is too hot and will shut down". This message disappeared after a few seconds and the Nav display is working fine.
I installed the module on Saturday and I haven't had any problems with the car since. Now I know that was only two days ago, but if I see anything else occur, I’ll post about it.


Unresolved Questions / Issues
  • When I have an incoming call, the Caller ID on the DIC shows "UNAVAILABLE". However, this may be due to the Bluetooth capabilities of the cell phone.
  • Also, as this is a used module, I'm not sure if OnStar will be willing to reset the programming on the device to match my vehicle. Therefore, I don't know if I will be able to activate OnStar services on the vehicle. The good news is the OnStar light is green. I might look into it if I decide to activate OnStar in the New Year. There is a guy on the Silverado forums who said he called up OnStar and they downloaded the updated information about his car to the module. However, I'm unsure if he had a new, or a used module.
Of course I can’t make any guarantees if will work in your car (As I said my car has Nav and was manufactured in March 08. Also, I don’t have THAT much experience with electrical or automotive systems, I’m an IT guy) but hey if you’re looking for a way to add Bluetooth to your 08, this MIGHT be a way to do it.
 
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#207 ·
Hey strunkm,

Glad to hear it worked out for you.

Gotta ask: when you receive an incoming call, do you see the Caller ID on your dash, or does it appear as "UNAVAILABLE"?

I still got to look at that at somepoint haha. Doesn't bother me much though (hey, I've lived with it for almost a year).
 
#210 ·
Gotta ask: when you receive an incoming call, do you see the Caller ID on your dash, or does it appear as "UNAVAILABLE"?

I still got to look at that at somepoint haha. Doesn't bother me much though (hey, I've lived with it for almost a year).
Gramzster, I replaced mine with a 2010 model and I do see the caller's # on my DIC. I followed your instructions (thanks again), so I would think it has to do with the cell phone. What do you have? I'm using a Samsung Galaxy S Epic. Can you try pairing a friend's phone to see if the results are different?

Also, when I had mine at the stealership, I told them about the update and printed out what needed to be done to match to my car. Their advise..."I'd leave for the next person that buys the car to worry about". I told them I still wanted it and they were supposed to give me a quote and do it while it was there...they never did. This is one more reason why I'm changing dealerships.
 
#212 ·
What did you do about the bluetooth antenna?
I'm not sure what you mean, but the new module I purchased came with the bluetooth antenna which plugs into the module. My module came from a 2010 which is positioned by the glove box from what I understand, whereas mine is located on the back shelf...no problems with reception/distance. I still haven't gotten it reprogrammed at dealer or Onstar yet, but I get green lights and everything works great. I don't have Onstar service, so it's not that big of a deal for me.
 
#213 ·
Anyone in Columbia SC done this ? I just got an 08 CTS4. Dealer said he had BT but it does not. :banghead: I searched ebay today but did not find what looked like an ONSTAR Bluetooth module for the CTS.

I think I read you have to mess with airbags to do this and I do not know much about doing that.
 
#215 ·
You do NOT mess with airbags whatsoever. I used to live in Charleston but in Cali now. All this requires is for you to locate an Onstar 8.0 or 8.1 (whichever and the hardest part). Then remove your back seat (easy) and rear deck shelf (also easy and instructions on first couple pages of here). Swap modules and voila! Afterward, take it to a dealer and have them flash it. Then push Onstar button and have them associate to your car. It was extremely easy install. If you read the first few pages of this you can skip the rest. The other 13 pages are more about how hard it is to find a part lol.

On another note, ordering online at partsdirect does NOT work. They will let you submit it, but never send it.
 
#217 ·
After searching everywhere on the web, I finally found mine at a local 'junk yard' that just happened to have a 2010 cts from collision. I was actually there to check out a glove box, as mine had scratches in it when I bought it. I'm glad I asked about the onstar module though, because they checked and it was still in the car (behind glove box in 2010). They wanted $250 and I was too excited to haggle. I was worried because it wasn't the same model # as those described in original writeup, but installed it that day in probably about 2-3 hours taking my time and following the directions...it works great. I have yet to get dealer to reflash to associate to my VIN, but I get green lights and I tested to make sure it dialed out to Onstar...although I don't subscribe...and it did.

matthayes3741 is 100% correct...the hardest part is finding the part.

Don't bother using an online used part finder either, you'll get about 5 different people emailing you to call them because they have the part, when they don't...it's all automated. Most of them were rude when I did call them...like they didn't want to be bothered.

PS: The closest you come to the airbag system is removing the fuse (just in case).
 
#219 ·
no more functions but there was a recall on the Onstar 8.0 module (the second one) which is something the Onstar 8.1 module fixed. I know looking at 15 pages is a lot of reading, but read through the first 3 pages and your questions will be answered (including nothing about the airbag and discusses the TSB/recall). The subsequent 12 pages are about people trying to find them lol.

Good luck!
 
#220 ·
Thanks for the help. I read the pages but was just trying to be sure. Multiple answers sometimes, and I was looking at multiple sites too. Confusing.

Wish I could just take it to the dealer and say put the BT version of the module in!
:crying:

And now I am trying to figure out the USB options... think I got that one worked out but another what the heck were they thinking thing !!
Thanks again!
 
#222 ·
I just bought my first Cadillac yesterday. It's a '08 CTS4, and of course, does not have Bluetooth. I was really suprised, considering it has the Premium Collection. This thread is excellent. As with everyone else, I'm having trouble finding the mentioned PNs. Is there any reason that I couldn't use another module, as long as all the connectors are the same? I have found one, and only the mounting would have to be changed. It's PN 20842731.
 
#224 ·
I am no expert, like you, I just got my first Cadillac a few weeks ago, 08 CTS4 DI performance and luxury packages, but have the same results in my searching. Seems you can't have the best of both worlds. yet.:hmm:

Seems like some auto electronic engineer could whip out a ton of mods and updates for these cars. It is running Windows and has a USB port...but again, I have no experience with Windows Automobile edition.

Some day... A program to use the Nav screen for engine gauges and monitors etc would be really useful. But maybe most Cadillac owners are not interested in that kind of thing.
 
#229 ·
I am not qualified to say. I have not used galaxy or bluestar. I have read posts here from folks who have problems with the bluestar. And I have read posts from people who love it. You will have to make your own decision. Me personally, I would pay the $300 or whatever it is and try it out. If it didn't work, I would just write it off as another failed experiment. I think it's worth the stretch. But that's just me.
 
#230 ·
Hello all. Ive read every page of this thread. I'm hoping somebody here can help me. I have a 2006 DTS. I got a VCIM from a 09 Impala and installed it in my car. The module works flawlessly except for one minor thing. My phone will not reconnect automatically when I reenter my car. I have to repair every time. I have a friend who is a GM tech. He brought his tech2 computer(thingy) and "programmed" my onstar module. I watched him do it. It took him less than one minute after connecting to the cars computer. When it was done my windshield wipers activated to confirm it was complete. Is this a true reprogramming or just some reprovisioning to onstar? The light on my rearview mirror is dark. Not red or green. I did press the phone button and it did connect me with an onstar advisor. I do not have onstar service. I just need the thing to reconnect to my phone(iPhone). If I have to repair every time I get in my car it wont be worth it. Ive tried a friends blackberry as well as an android phone. They all have the same results. Also, is there any voice command that will make the system tell me all the stored bluetooth devices? It will only tell me the one that is currently connected. I have no idea if the person before me paired their phones as well. Any advise would be greatly appreciated. PLEASE HELP ME.
 
#234 · (Edited)
Thanks so much for info guys.

Elizabeth - I know it wasn't offered as an option on my car but God willing and given enough time it will work as if GM itself reached out and made it so.

Jimmy - This might be it. The module does retain the names and phone numbers I've stored. It also retains the name of the pairing for my phone. I know this because when I go to re-pair my phone I have to call it another name. If I try to call it the same name the computer responds "That sounds to much like.......". I have to assign it a different name and then delete my previous name.

Rab - Listing all paired and connected devices: I get through the prompts you posted but when I give the voice command "List" it says "Im sorry but no bluetooth devices are connected" or something very close to that. When I give the "Delete" command I receive the same response. The only way I can get "List" or "Delete" to provide a different dialogue is by pairing my phone first. I paired my phone again today and deleted my previously paired name. I tried using the Delete command followed by different names in the hopes that it might find some stored paired name that is close in nomenclature and ask me if I want to delete it. But that proved fruitless.

If I try to manually connect with my iphone, after exiting the vehicle and re-entering, my phone will show connected and then immediately go to unconnected. Ive read through many forums and found TSB# 08-08-46-008B. Since this VCIM came from an 09 Impala, does this seem likely? Also, if any of you are GM techs and have ever reprogrammed an onstar module, how long did it take once your computer started the reprogramming? I know its far fetched that ill ever find an answer to that but I have to ask. My friends computer did the programming in less than a minute. That seems fast to me. I thought it overwrote/reinstalled the current software on the vcim. I have no literature or evidence otherwise to support that. I asked my friend and he did not know. Maybe its just a small software patch and that is normal?

Is there specific way for me to test the power/memory retention of the module itself? If you guys have any feedback on something I can test or otherwise, please let me know. Again thanks for all the information. If I need to Ill purchase another VCIM.


****quick edit: The light on my mirror is off. Not green and not red. Its just like its been turned off. I can connect to onstar. As a test I pressed the button and it connected me with an onstar advisor who thought I was in a 2009 Impala. Is the light being off normal?

****quick edit#2: Confirmed that Onstar is version 8.0. This was done by holding down the phone button. Working off the assumption more info is better than less info? :)
 
#236 ·
phigment, via ChiltonLibrary.com I've downloaded the OnStar wiring schematic (in .pdf format) for your 2006 Cadillac DTS, then uploaded it to my account at KeepandShare.com. For your ref/study here's a link to that file: http://www.keepandshare.com/doc/view.php?id=2857329&da=y

My thoughts are.. the wiring for OnStar that exists in your '06 DTS may not be quite compatible with the wiring requirements of the '09 Impala VCIM you have installed. I recommend you try to locate/download the OnStar system wiring schematic for a 2009 Impala and compare that drawing with the one I've provided here for your '06 DTS. Hopefully you may discover that moving or adding a wire or two in your DTS's OnStar wiring/circuitry will solve the problems you are facing. Good luck.
 
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