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*.
⇓ 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. ⇓ ⇓ ⇓ ⇓ ⇓
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)
b. Front side trim (passenger’s side)
c. A-pillar trim (passenger’s side)
d. Passenger-side lower panel
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.