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Factory OEM SiriusXM nearly working in Tesla 2022 Model 3

I did a lot of forum and web searching and never found any other posts that got this far, so here I am now. See attached picture.

  1. I have a Tesla OEM SiriusXM tuner installed in a 2022 Tesla Model 3 Long Range
  2. The MCU recognizes the tuner
  3. I have SiriusXM audio source listed (and enabled) under the Audio Sources
  4. I put a subscription on the tuner
  5. I have an aftermarket SiriusXM antenna attached to the Tesla OEM tuner, and Tuner is able to receive SiriusXM satellite signal.
  6. Tesla SiriusXM is fully functional for channel navigation and tuning on the built in main Tesla LCD screen (as reported by the Sirius channel text/graphic changing and current song being listed)
  7. The FM radio is fully functional in tuning and outputting audio through the sound system. (Note on FM antenna later)

The one thing that doesn't work yet is the audio for the Sirius streams when tuned. The audio heard over the speakers is the last tuned FM radio station.

The one missing physical part I need is on order and should have it in a few days is a dual Fakra to single Fakra for the (non-glass) OEM Tesla FM antenna. To confirm the FM radio works and tune stations, I used a bit of jumper wire and held it into the Fakra connection and did indeed tune properly and played music over the speakers. Because I'm holding the wire in by hand, I can't attempt to switch to SiriusXM on the screen while holding the antenna in to see if that makes the SiriusXM audio work. However, I don't believe that will make a difference to the SiriusXM audio. Since I had little confidence all of the prior steps would work up to this point, I didn't bother ordering this last adapter. Since it does, I've ordered it, but it hasn't arrived yet.

I'm happy to can talk a lot about how I've gotten to this point, but I'm reaching out to the community to see if anyone has any tricks to try to make the SiriusXM audio come out of the speakers when tuning a SiriusXM stream instead of the FM.

Things I've tried so far:

* MCU reboot (press both steering wheel buttons with foot on brake until black screen then when Tesla logo appears release buttons/brake.
* Tesla regular software patch update. I specifically did not apply the software patch until I had the Tesla OEM SiriusXM tuner in place thinking I'd need the patching process to get the car to recognize the replacement tuner. I didn't need the patch to get this far. Allowing the update patch did not appear to change anything positive or negative.
* Full power down of Tesla. Meaning disconnect 12v lithium battery under the hood, and disconnecting the pack connector under the back seat. I did this BEFORE the tuner was recognized, and haven't done it since, so there's an outside change this may do something, but I'm not hopeful.

Does anyone else have any ideas or background technical info about why the car sees the tuner and can clearly interact with it, but the sound is still coming from the FM radio portion when the SiriusXM sound source is chosen from the MCU?
 

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I know nothing about it but my guess is that even though the MCU can recognize the SXM module and that makes the computer/display work, there's a line of code missing and the MCU can't switch the audio source to SXM. Or maybe the SXM input (on the audio amp portion) isn't hooked up or there's a SXMenabled = false in the code somewhere. That's why you hear FM: it can't switch to SXM input because there is none in the audio amp... or it's disabled.

Or it could be that the audio amp itself doesn't even have an SXM input or it's there but it isn't wired to save money (because it isn't supposed to be used).

Mike
 
I know nothing about it but my guess is that even though the MCU can recognize the SXM module and that makes the computer/display work, there's a line of code missing and the MCU can't switch the audio source to SXM.

Certainly possible.

Or maybe the SXM input (on the audio amp portion) isn't hooked up

From examining the connector diagrams over on Teslatap all the audio inside the tuner itself (both FM and SiriusXM) is encapsulated in ethernet before leaving the tuner.

From this Teslatap.com article:

"The digital radio connector uses the TE Connectivity 2302475-2 housing and requires five terminals TE Connectivity 2-1703930-1. This connector only has power and ethernet data (4 wires)."


or there's a SXMenabled = false in the code somewhere. That's why you hear FM: it can't switch to SXM input because there is none in the audio amp... or it's disabled.

There are a couple ways I can hear audio change (from FM static which is what if have right now) to complete silence, then it drops back to FM static. So SOMETHING is happening.


Or it could be that the audio amp itself doesn't even have an SXM input or it's there but it isn't wired to save money (because it isn't supposed to be used).

Mike

I don't think this is it because there's not separate SXM audio input into the MCU. Its all ethernet from the SXM/FM Tuner mounted on the passenger C pillar to the back of the MCU in the dash.

I appreciate your suggestions and contributions, however. I went into this knowing that its very possible this may not work, but luckily the Tesla OEM SiriusXM tuner still appears to fully work for FM (once I have the FM antenna adapter in place. So I can leave this in and not have any lost functionality even if I never get the sound from the SXM to work.
 
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Interesting. I had no idea how it worked. So you're saying the tuner in the C pillar handles FM and SXM? Where is the OEM built in FM tuner? Does this FM/SXM tuner replace the stock FM only tuner? I'm just wondering if it's all ethernet and FM and SXM are in the same tuner box, maybe the signal to switch the tuner from FM to SXM isn't reaching the tuner (from the MCU)?

Mike
 
Interesting. I had no idea how it worked. So you're saying the tuner in the C pillar handles FM and SXM?

This is where the FM tuner lives in the Model 3. The model 3 stock tuner only does FM/HD.

Where is the OEM built in FM tuner? Does this FM/SXM tuner replace the stock FM only tuner?

Same place. I bought the equivalent Tesla OEM tuner (which does FM/HD/SXM) that comes in the Model X (with SXM).


I'm just wondering if it's all ethernet and FM and SXM are in the same tuner box, maybe the signal to switch the tuner from FM to SXM isn't reaching the tuner (from the MCU)?

Mike

There are 3 connectors on the stock tuner:

* FM antenna #1 (single Fakra connector coming from FM antenna preamp I believe)
* FM antenna #2 from rear window glass
* TE Connectivity 2-1703930-1 connector (this is the one I talked about above. Which has power positive and negative, and 2 wires for ethernet)


There are 3 connectors on the Model X tuner (with SXM):

* FM dual antenna connector (dual Fakra connector)
* SXM antenna
* TE Connectivity 2-1703930-1 connector (this is the one I talked about above. Which has power positive and negative, and 2 wires for ethernet)

All the FM and SXM traffic is all ethernet as thats the only way sound leaves the tuner and control commands from the MCU enter. This is why I gambled that the Model X tuner would be able to talk to the Model 3 MCU. I theorized that Tesla didn't write multiple versions of the infotainment portion of the MCU. That guess was right.

Possibilities of the problem I'm having are:

* entirely possible there's a software flag that isn't set in either the MCU or perhaps even the Model X tuner
* I could have defective Model X tuner.
 
I meant to post this picture in the last reply. Here is the Model X tuner mounted in my Model3. At this point I hadn't plugged the SXM antenna in yet. Its the thin one on the top left next to the 10mm bolthead. The larger white one is the dual Fakra for the FM antenna.
IMG_3992.JPG
 
OK. I get how it works now. Hope you don't mind me spitballing ideas when I've never even delved into this. I'm a software engineer so I thought I'd just chime in with some ideas since I could probably predict some of what they did without actually knowing.

Tesla is good about reusing parts (and likely code) across models so I too would have thought you'd have a good chance. The fact that the UI picks it up means at least that part is probably a common branch of code. Sometimes though, you run into pieces of the code that just doesn't run the same way due to something being different about the connectivity. If the software is not expecting an SXM tuner, the code may have a list of valid values or even is missing some functions because those just don't get compiled for a Model 3: no reason for it to send an SXM signal when it isn't expecting the tuner to include it.

If that's the case, hoping the ethernet datastream is the same, one option might be to see if there's a way to get the tuner to start in SXM mode by default. If you hear FM (last station selected), the tuner probably starts in FM mode by default. Wonder if you could trick it into starting in SXM mode instead. No guarantee the MCU would be able to send control signals to change the station, but at least it'd be a start? Someone good with CANBUS and maybe rooting of Teslas could probably put together some sort of controller/converter if needed.

Mike
 
So just to get this correct the ports are (see attached)???

1) xm antenna
2) dual fm antenna (why does the s/x need dual input)
3) Ethernet

Also does the tuner have a specific xm radio ID?

I may pick up a model s plaid fm/xm tuner to mess with.
 

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I think the bottom line here is that the focus is on that ethernet connection. Some relevant questions are:

(1) Does the Model 3 have the required code to send/receive commands to the module (select source - FM/SXM, change channels, etc).
(2) Is the audio data stream compatible with the Model 3's code?

Since the OP indicated hearing an FM station, it might be a good assumption that the answer to (2) is yes (likely no reason for SXM to have a different audio encoding than FM). Then we're just down to control signals and whether or not the Model 3 is set up to send and interpret them. Some "sniffing" might be possible to detect whether or not the Model 3 MCU is sending signals when the audio source is switched and channels are changed. If so and the signals are just not compatible with Model X signals (from which the module came), then it might be possible to build a simple Raspberry Pi converter to insert in the ethernet line although I have no personal experience with that.

Or maybe we're just getting ahead of ourselves and the part that is on its way will fix it without any further modifications?

Mike
 
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OK. I get how it works now. Hope you don't mind me spitballing ideas when I've never even delved into this. I'm a software engineer so I thought I'd just chime in with some ideas since I could probably predict some of what they did without actually knowing.

Mike, this is EXACTLY what I'm looking for, spitballing ideas, and even introducing the software side. I have an electronics and IT background. I can script in Python (or Ruby, or Bash), but wouldn't call myself a coder.

I like your analysis about the M3 MCU not having the code to call the SXM channel change. That is entirely possible. I was hoping that Tesla was lazy and didn't fork the MCU code between MX and M3.
 
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So just to get this correct the ports are (see attached)???

1) xm antenna
2) dual fm antenna (why does the s/x need dual input)
3) Ethernet

Also does the tuner have a specific xm radio ID?

I may pick up a model s plaid fm/xm tuner to mess with.


1) yes
2) yes (Model 3 ALSO has dual FM antenna input. One is a single Fakra and the other is the black square connector that connects to the rear window glass antenna)
3) Ethernet and power. 2 wire ethernet and positive and negative power each on their own wire


It DOES have a radio ID. I was able to see it in the MCU on the Subscriptions tab. I was able to subscribe to SXM using this ID, and can browse to other streams which show the text of the song being played now that there is an active subscription.

As far as picking up a tuner. Make sure your S tuner (or X as I did) DOES have SXM. Both cars have a tuner that DOESN'T support SXM. See the article on Teslatap for the part numbers.
 
1) yes
2) yes (Model 3 ALSO has dual FM antenna input. One is a single Fakra and the other is the black square connector that connects to the rear window glass antenna)
3) Ethernet and power. 2 wire ethernet and positive and negative power each on their own wire


It DOES have a radio ID. I was able to see it in the MCU on the Subscriptions tab. I was able to subscribe to SXM using this ID, and can browse to other streams which show the text of the song being played now that there is an active subscription.

As far as picking up a tuner. Make sure your S tuner (or X as I did) DOES have SXM. Both cars have a tuner that DOESN'T support SXM. See the article on Teslatap for the part numbers.
When do you think you’ll have the last piece of hardware you need?
 
When do you think you’ll have the last piece of hardware you need?

The last piece was the dual Fakra female to single male Fakra (x2) connectors.

I got it last night, and eagerly installed it. As expected, it didn't change the SXM audio. The FM radio (and HD for that matter) signal works perfectly now on the Model X tuner in my Model 3 (without my handheld jumper wire), but thats all. I also tried to do a full powerdown of the car (disconnecting 12v battery as well as high voltage) in hopes it would change the situation and it did not.

At this time the MCU SXM app is fully working showing both channel icons, as well as listing the active playing song by name when I SXM switch channels, but the audio coming out of the speakers is the last tuned FM channel.


So with what I understand how the hardware works that leaves us with 3 possibilities:

* The Model 3 MCU is NOT sending out the command to change streams
* The Model 3 MCU is properly sending out the command to change streams but the Tesla OEM tuner doesn't know what to do with it.
* I have a defective Model X tuner
 
Yeah it seems like there is a line missing in the code to tell mcu to switch sources. But the fm playing sound only does remind me of when I have my portable xm radio on but my Tesla radio not tuned to the right frequency/station (I have my portable xm connected through fm direct adapter)
 
Yeah it seems like there is a line missing in the code to tell mcu to switch sources.

If its just the MCU doesn't send the signal on the CAN bus to the Tesla OEM tuner to switch audio output from FM to SXM then there's an outside possibility to work around this with some help from others.

I already have S3XY buttons installed in the car (because Iike having buttons I can push to increase decrease HVAC fan speed without taking my eyes off the road). The S3XY buttons work by having a module plugged into the CAN bus and talking directly to other devices instead of having the MCU do it. The Tesla radio tuner (both M3 and MX/MS) is NOT manufactured by Tesla, so its unlikely its running proprietary code written by Tesla.

If we can learn what command the tuner is expecting to receive to switch audio source, we might be able to ask the S3XY buttons manufacturer to add the "radio tuner source" as an option in their app. At that point its just using the existing S3XY buttons smart phone app to program a hardware button for FM or SXM audio source, then using the MCU to perform the channel switching (which it already appears to be doing properly). when a programmed S3XY button would be pressed, the S3XY buttons commander would send that command over CAN bus to the radio tuner solving our problem.
 
Just one note to others doing what I've done so far. Even though the tuner is made by the same manufacturer for M3 and MX and is even the same dimensions, the mounting bracket on the M3 tuner is VERY different. Its riveted to the M3 tuner. So your choices are:

* bulding your own mounting bracket. Keep in mind it looks like the C pillar is used as a heat sink, so make sure you have good surface connectivity.
* drilling out the rivets on your M3 tuner, then drilling the same holes in our MX tuner then using fasteners to join the two.
* disassembling the M3 and MX tuner and swapping the bottom half of the housing and slight bending the port openings at the antenna side to accomidate the MX connectors that are wider than the M3 connectors. Also the inside of the housing is a heat sink and has nearly the same IC layout between MX and the M3 tuners. There's one IC that ISN'T there in the M3 that IS there in the MX. I scrapped up some of the thermal compound and placed it on that missing IC and did some tests to see I had good thermal connectivity.
 

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