View Full Version : XM Antenna Connection

06-04-13, 07:46 PM
I have a 2006 Cadillac STS with the non-navigation bose stereo system. The dealership that I purchased this from has activated the XM 'trial' subscription for 30 days. I have been able to identify that the black 'fin' antenna on the roof is for the satellite radio functionality. I have a handheld Delphi MyFi radio with an active XM subscription that I use in my 2000 Cadillac SLS, but connected to an antenna I installed myself on the roof. Does anyone know if I can install my portable XM radio into the 2006 Cadillac STS and hook it to the roof antenna all ready installed on the vehicle? I am assuming this antenna has to feed back to the receiver somehow, any idea which wire(s)?

In advance, anyone asking why I'd like to use my Delphi MyFi instead of activating an account on my dash receiver, it's because I only want one active XM account and I'd rather have it on a portable device I can plug into my home receiver as well as my car receiver.

06-04-13, 08:20 PM
I don't think the trial subscription is transferrable. Nor will you find it easy to add MyFi to an STS.


06-04-13, 09:40 PM
The antenna on the roof is also for OnStar and will have three cables coming out of the bottom. The gold/tan cable is for XM (black and blue coax cables are for OnStar). I've never tried to interface this antenna to anything except an OEM receiver so I don't know the answer to your question with certainty. You may be able to find an RF shop somewhere that can build you a cable, but again, I don't know for sure if it will work or not.

06-08-13, 11:58 AM
Ok, didn't really want to transfer the 'trial' just wanted to point out I had verified it had XM capability because I noticed the active 'trial'. MyFi shouldn't be difficult to add to my vehicle. It communicates through built in FM transmitter to my 2000 SLS just fine. It gets the signal from the XM antenna that I installed on the roof.

ddalder, thanks for the wiring information. Do you happen to know if that feeds back directly to the head unit or if it goes to an XM module hidden in the vehicle somewhere before going to the head unit? If it does go to a module, would you happen to know where they've placed it (trunk, behind the glovebox, under dash, etc...)? If it goes to an external module, I'm thinking I'd have to make the connection between the roof antenna and the XM module...but if it's built into the receiver then I wouldn't have to worry about that.

Delphi designs and builds the GM radios. There is a good chance that the style of connector used to attach the external antenna to the head unit and/or xm module would be the same as what I would use to connect to my portable device. If not, there may be a converter cable available online...or I can have one built. Either way, I won't know what avenue to take until I can locate where the wires go to.

I'd consult my owners manual, but this is a used car...the dealer threw a CTS owners manual into the glovebox because it was missing the STS one and that's all they had laying around.

06-09-13, 02:09 PM
I think it is in the trunk. Aftermarket add-in's frequently pirate the STS XM feed to provide additional feature/function.

Too bad about the lack of manual. They're cheap at Helm.com and free in pdf at the links in the 'Sticky' thread at the top of the forum.

06-09-13, 02:56 PM
The antenna connects directly to the S-Band receiver which is mounted on top of the rear deck (passenger side). It mounts to the same plastic carrier that your right rear speaker attaches to, along with the sub-woofer (in so equipped cars) and the trunk lamp assembly. This is accessible from the back seat but you need to take out the back seat, left and right 'C' pillar trim (also called sail panels) and the rear deck trim panel. I'm not certain who manufactures the S-Band receiver for these cars, however the radios for the 2005+ STS are manufactured by Denso, not Delphi. The connector however seems to be standard in any of the newer GM vehicles (2003 and older used two connectors for the XM antenna, newer vehicles use a single coax).

06-09-13, 07:10 PM
Thanks for the information ddalder. Are you sure it's a Denso? My understanding was that Denso had only supplied the Nav systems. It's hard to know who supplies what anymore because even when I worked at Delphi I remember the systems were a hodge podge mixture. They would use pioneer/clarion cd playing mechanisms, Denso LCD screens, etc... Plus, I don't know what to believe in a name because the lab I worked in was all ways testing audio technology developed by Delphi which was sold and rebadged as Rockford Fosgate, Clarion, Bose, etc... Most of those companies would then 're-engineer' the stuff.

The Delphi media page says that for the 2005+ STS (what does plus mean?) they supplied:
"Satellite Digital Radio Receiver and Antenna
The STS will include Delphi's Satellite Digital Radio Receiver and antenna as optional equipment. The system will be able to provide STS owners with XM Satellite Radio programming, which includes up to 100 channels of satellite- broadcast entertainment. The user interface of the system is simple and similar to traditional AM/FM radio with additional information including channel, type of music, song and artist name"

I don't remember all of the models that went through the labs, I only messed with radios a little bit between 98 and 01. So early OnStar, RDS, XM, etc... stuff that probably went into cars between 99 and 03 and only on benches so never seeing vehicle integration. I was going to try and contact some of my old colleagues but very few survived the bankruptcy, they cut like 75% of the Test Engineering staff and most others 'retired' or were cut a few years later when they still had problems.

06-09-13, 07:24 PM
2005+ means 2005 and newer. You're right, I was thinking of the navigation radio. Looking at some pics of the standard 2005+ radio on eBay, it appears these are made by Siemens. The S-Band receiver may well be Delphi. There have been no markings on any of mine (externally anyway) that lead me to conclude who manufactures this component. Looking through some other sites at antenna connectors, the one used on the S-Band receiver and antenna are a FAKRA connector (SMB connector with a colour coded, keyed plastic housing).


I do know that it's possible to remove the lock from the side of the plastic housing and extract the SMB connector (for any crimped onto coax). PCB mounted I'm sure are a different story.

06-10-13, 08:26 AM
[QUOTE="EChas3;3480689"]I think it is in the trunk. Aftermarket add-in's frequently pirate the STS XM feed to provide additional feature/function.

What additional features or functions would one gain by hacking the module?

06-10-13, 11:29 AM
Thanks for the information ddalder, that's a lot of help. I plan to begin the adventure this week.

B1n2fra...not looking to hack the module rather than just steal the cable connection to the roof antenna. I have a portable XM radio that I would like to connect to the roof antenna. While it's nice that my STS is equipped with XM functionality, I am not going to cancel my subscription for my portable radio and as long as I have a good working portable unit, it makes no sense to pay for an additional subscription to be stuck in my car. I use my portable unit connected to my home audio system and with a small speaker system when I go tailgating with friends or out by the firepit.

Also, I don't want to run an additional antenna if I can all ready utilize one that has the wires 'professionally' hidden. I plan to power my portable unit in the arm rest and even probably store it there...it has a remote control that is RF to change the channels. The only hack I can think of that would be sweet is to use my factory stereo xm band features to control my portable satellite radio...for that I might have to start another thread.

I know that I'm all ready looking into the threads about replacing my onstar module with a bluetooth module...just not interested in paying $279 for stupid bluetooth functionality through the stock system, before doing that I have to determine if my system has bluetooth as an option or not. I know OnStar offered it for some models, but haven't looked into if mine has it or not. By the time I'm done, I'm sure it would have been easier and cheaper just to swap the entire audio system out :)

06-10-13, 03:38 PM
Can you not simply add an additional receiver to your existing XM account and just activate the radio in the car? I have XM as well and have been wondering about getting a unit for my home stereo. If I have to have two subscriptions for that there's no way I will do it...

06-10-13, 04:50 PM
curtc, I asked the same thing when I had my '04 deville. This had the XM option even though it was a base deville. I called the customer service and asked what my options were. They basically told me that I was able to add the receiver to my existing plan but still had to pay for an active subscription for that receiver. They were willing to offer me a discount for having multiple devices active (you have to push for this because they don't "offer" this officially anymore). They gave me some line that if they didn't charge me then I could just have multiple friends add their devices to my account, etc...($$$).

06-10-13, 05:47 PM
Wow...Why can't they just be like Netflix or Hulu and just give you a set amount of devices you can activate on one account? That's just dumb! Well, there goes that idea....

06-10-13, 09:28 PM
Z- You'd have to run antenna wire from the trunk to the armrest console to put your portable there. I don't see how you'd be able to use the factory radio to control it. Bluetooth for hands-free phone is no biggie but for audio is much harder.

B1n- Aftermarket designers tap the XM line-in for audio and can use the tuning control and Nav display on models so equipped.

06-12-13, 11:35 AM
EChas3, I figured I'd have to run the wiring from the trunk to arm rest. I've figured out the methodology behind using the factory radio to control my portable xm radio...I just have to use one of my datalink modules and some software to interpret the device IDs, specific messages, etc... Long story short, I can use a PicMicro or Arduino to replace the xm module and talk to the radio, as if everything is as expected.

I can then have the device I've made communicate through RF to my portable module, interpreting the radio button presses. The portable device has built in FM modulation, but that's of no use because I'll be on the XM band of the radio. It doesn't really "broadcast" the kind of information I need otherwise...I could have the device I build receive the FM modulation, interpret that and send it to the factory radio. Too bad I can't find a way to create a device that can 'clone' my portable xm radio so that I just drop that in place of the factory xm module and don't lose some signal with RF and FM modulation!

In the end, anything is possible...impracticle maybe, but definitely possible. At this point, it's not a matter of what's easier...it's a matter of a challenge tempting me to tackle it :)

06-12-13, 08:19 PM
I'm looking forward to reading of your success.

Party on!

06-13-13, 12:03 AM
Or epic failure :p