Adding XM to non-Bose® Infotainment system?

Go directly to:     Accessing the TAU


A few people have inquired as to whether it is possible to add SiriusXM Satellite radio after-the-fact.  I thought XM was unique to the Bose setup, but the service manual implies that the only electronic difference is the additional Bose amplifier unit.  This might explain why those of us with the non-Bose system find a XM activation card in our glove box – because perhaps technically we have a XM radio in the car (just not the antenna).  According to Mazda’s Service Manual, it appears that the XM tuner is already contained in the Tuner & Amp Unit (TAU) that is common to both Bose® and non-Bose systems already, and if that is the case, it may simply be a matter of plugging a XM antenna module into the TAU to end up with XM capability. The actual system schematic is here.

I don’t think I would add the shark-fin antenna though, as there are more subtle versions available.

⇓  Here is one from Terk for $16 that looks like it plugs right in.  Because our cars are convertibles, locating the antenna on the dashboard or somewhere behind the seats may work just fine*.


am3uun00003597⇓  Here is what the factory XM antenna wire (yellow “FAKRA” connector) looks like plugged into
⇐  this “FAKRA” port in the TAU…


If my theory is correct, after the antenna installation, the CMU should recognize the XM capability and it would be added as an audio source.  I may not even have to disconnect the battery ground, before installation like you normally do with anything electronic. If XM isn’t recognized, I’ll do that step and hope that when reconnecting the negative battery terminal XM will be recognized.

So, it is my understanding that during the 60-day free trial (and later, with a XM subscription), live traffic data might also be fed into the Navigation system.

I’ve ordered the Terk antenna and will give it a try.  ⇓  ⇓  ⇓  ⇓  ⇓

[UPDATE 4/11/2017]
Well, as it turns out, apparently the TAUs are different between the Bose version and the non-Bose version vehicles, as there was no XM antenna port to plug the antenna into (nor was there even a punch-out in the steel housing for said port).  The TAU modules can’t be exchanged, because the amplifier board in the Bose TAU is different as well, as it is merely a pre-amp that feeds the 281 watt Bose amplifier module behind the seats (with all different wiring harnesses), rather than the self-contained 100 watt amp in the non-Bose TAU, and it wouldn’t be able to feed your speakers.

I will say though that anyone wanting to delete the shark fin from their trunk lid – yet still play XM audio, might want to consider the Terk antenna, which isn’t much larger than a quarter, and seems to be a really nice looking substitute that you should be able to find a suitable location for.  It does have a strong internal magnet, and it turns out that the narrow panel just ahead of the aluminum decklid is made of steel and might be one location to consider.  Personally, I think I would adhere it near one of the rollbars, as it would blend in better or perhaps tuck it into the plastic spoiler/CHMSL assembly.Also, removal of the trim (and reinstalling) was pretty straight forward following the directions below and isn’t as big a job as it seems on paper.  Had the XM jack been there, I would have been able to plug it in after steps 1 & 2 (without removal of the TAU).Regarding installation instructions (with photos) for items like this and backup cameras, an excellent how-to-guide was prepared by SargonDragon and makes a great reference document.Sam has identified a XM tuner kit that will feed through the USB port of your Infotainment system, much the same as the built-in XM tuner.  Steve suggested “…using the Sirius phone app and Bluetooth into the radio. Works pretty well as long as I have a Cell signal.”

arthritisdoc has had good luck with this: SiriusXM Commander Touch Full-Color, Touchscreen Dash-Mounted Radio  as he explains here.

SiriusXM satellite radio 

  • When the CMU receives the operation signal/detects the switch operation, it sends (1) the control signal to the TAU.
  • When the TAU receives the control signal, it switches (2) the tuner inside the TAU to SiriusXM satellite radio mode and initiates reception of radio broadcasts.
  • The TAU detects the radio broadcast selected by the user using the tuner in the TAU based on the electrical signal received (3) from the SiriusXM satellite radio antenna. The audio signal of the detected radio broadcast is sent to the speakers. In addition, the detected radio broadcast information is sent (3) to the CMU.
  • The CMU converts the radio broadcast information received from the TAU to a LVDS signal and sends (4) the LVDS signal to the center display.
  • The speakers output (5) the audio based on the audio signal received from the TAU. In addition, the center display indicates (5) SiriusXM satellite radio information based on the LVDS signal.

*    Found this regarding placement of the antenna inside the vehicle:

The main reason why XM and Sirius recommend not installing inside the car is because any metal surface over the antenna degrades the incoming signal. It also helps to have the antenna mounted on metal, but this is less critical. Since the Miata has very little metal in the roof (just the A pillars and the top frame) it makes mounting the antenna on the inside of the Miata a non-issue. I have a Nissan Murano too and had the XM antenna mounted in the 3rd light area because the rear hatch on the Murano is made of plastic and has no metal. This makes it completely stealth. Center windshield area of the NA has a indentation that is the same size as the small XM car antennas. Velcro works perfectly. I have 0 [signal] drops in the Miata.

Accessing the TAU

Hopefully, just to plug in the XM antenna cable and route it to somewhere behind the seats, only Steps 1 & 2 will be necessary.

1. Disconnect the negative battery cable.

2. Remove the following parts:

a. Scuff plate (passenger’s side)amxuuw00002780



b. Front side trim (passenger’s side) amxuuw00002750

c. A-pillar trim (passenger’s side) amxuuw00002746

d. Passenger-side lower panel amxuuw00002778

3. Disconnect the connectors.


4. Pull out the wiring harness clips.

5. Remove the bolts.


6. Move the tuner and amp unit (TAU) in the direction of arrow (1) shown in the figure and detach the guide from the body.


7. Move the tuner and amp unit (TAU) in the direction of arrow (2) shown in the figure and detach the positioning pin from the body.

8. Pull out the tuner and amp unit (TAU) to the position where the connector can be pulled out in the direction of the arrow.



13 thoughts on “Adding XM to non-Bose® Infotainment system?

  1. This will be interesting. Among other confusing live traffic info, when I contacted Sirius/XM Tech Support last fall, their tech said their traffic is a separate subscription channel which provides information but does not interact with factory nav systems. But he also sounded confused so…maybe/maybe not?


  2. I could very well be wrong, but I remember reading that someone had it working in their MX-5 and it provided upcoming traffic alerts in the status bar without even programming in a destination (can’t find that comment now though). If the experiment is a bust, I’ll just leave the antenna installed anyways if XM works. If XM remains non-functional, I hope to return the antenna.


  3. Just as interesting will be whether someone who only wants to listen the Sirius/XM on a factory non-satellite car can do so by just plugging in an antenna and subscribing.

    Liked by 2 people

    • Yep, I’m not that interested in traffic updates but would like to have Sirius. Even though I have unlimited data on my cell phone, there are still areas that the cell signal cuts out and the streaming then stops.


  4. Well, since the TAUs are in-fact different, it is most likely that the Bose TAU has a preamp instead of the 100 watt amp, since the Bose system has its own 281 watt amp unit, and wouldn’t be able to feed your speakers. The outer case of my TAU didn’t even have the opening punched out for the XM port, so I’m inclined to think that the schematic doesn’t reveal the inner workings as much as we’d like.

    At this point, I would advise against swapping components, and get XM by some other means.


  5. Kind of makes one wonder why, if they went to the trouble of using a different (no doubt less expensive) TAU, why they didn’t just skip the cost of creating the leg room limiting plastic block and stick the carpet down without it.


  6. The molded carpet doesn’t fit without the wedge simulating the subwoofer. They would have had to create two more carpeting units (LHD and RHD) for the non-Bose vehicles.


  7. I am adding a Sirius XM portable unit to my 2017 MX5 RF. It came with Sirius built in but I never activated and if I am paying for a subscription, I want to use it in multiple vehicles. My question is since my car has the shark fin XM antenna, would it be possible to ‘splice’ the stock XM antenna to my portable unit, thus not having to use the small cube external antenna?


    • I would just unplug it from the TAU and use that feed for your portable – but first, just try the portable antenna sine you are in a convertible.


  8. According to the current FiatUSA “Build and Price” tool, what was the (touch screen) Classica “Technology Collection” is now the “Technology and SiriusXM Group” (at the same price). Apparently now satellite is included without Bose. Which also implies traffic should drop through to the nav if you add the SD card.


  9. If that is correct, there must be a new TAU available for 2018 that includes XM and could theoretically be substituted for our non-XM version – for those wanting XM bad enough. Nice find, John.


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