Going dark

  The Yuppie Button page talks about making lots of light.  Now I needed to do the opposite, by "going dark" -- to vanish completely from Hyundai's data network, and avoid having the car being tracked or actively interfered with outside of my control.  See, this is one of the showstopping problems I have with Tesla -- they *insist* that you have your car online all the time, talking to Tesla's cloud and sending telematic data.  Thank you, NO.  The range of things that Hyundai's BlueLink setup is able to do remotely to someone's car given only a VIN is totally scary.  Not only did I want no parts of that, we all have every right to not participate in that nonsense if we so choose.

As a first step I refused to let the dealer sign me for BlueLink, telling them that I could handle signup later myself if I wanted to.  But I knew there was more to it, since the car as it came was still able to make a cellular data connection and send information about itself.  The obvious question was to find and disable the cellular communication facility, or "telematics unit" as it is implemented in many vehicles.

BlueLink trying to connect While working with the delivery guy in the dealer lot, I happened to press the "bluelink" button on the mirror which locked up the whole head unit into this stupid state that we then couldn't abort out of.  The delivery guy assured me that I had no configured service to "activate", as he had duly gone on the BlueLink website and made sure my VIN had no customer information entered.  We tried a couple of things including power-cycling the whole car, and eventually got the main screen back.  The prep guy said he'd double check that nothing untoward had happened during this nonsense.  But even getting screwed up to this extent told me that extra steps were needed to remove any path of intrusive remote control or monitoring.

In-car microphone disabled Somewhat related, an easy early fix was to disable the car's microphone in the headliner light assembly.  After all the OnStar spying scandals and similar, who wants their car listening to conversations in the cabin and being able to send that somewhere?  Sure, pulling this wouldn't let handsfree Bluetooth phone stuff work either, but I've never had much need for that and until I found the main cellular comms channel, at least what was said in the car would remain in the car.

Maybe another answer is to install an oscillator always cranking a VERY LOUD signal into the microphone leads, so that anyone enabling it to listen gets what they deserve.

Hard-to-remove garnish behind audio head unit Further study narrowed down the highest possibility of the cell modem location to within the audio/visual head unit itself.  With coaxial jacks in the back labeled things like "LTE" and "CDMA" in the schematics, it was pretty obvious.  Some sketchy instructions on how to remove the head unit were found on Techinfo, one step of which involved removing this "garnish" panel behind the screen.  Easier said than done -- a full hour of careful prying, prodding, peeking in underneath with a borescope, etc seemed fruitless for determining how to lift this one simple piece out without totally destroying it.  Finally I realized that it just took a little more force in the right places, and managed to work it loose one clip at a time.

[The pale plastic thing with all the black tape at left is my quick-n-dirty phone clip mount, ignore that.]

The panel detaches from the edge toward the screen and rear of car and hinges upward away from the screen bump, and then has to be slid to the left to release the two hooked lugs at the forward side.  Underneath are two out of four screws holding the head unit in; the other two are down on either side of the screen, accessible by pulling off the entire piece of dash trim underneath that runs all the way to the passenger side over the glovebox.  That was quite a bit easier, as it uses the typical plastic insert expandy-clips that most of the panels do.

Having a couple of non-marring plastic pry tools does help with this sort of thing; or taping over a thin screwdriver blade may also do in a pinch.

Audio unit connectors in back I could then slide the audio unit out, bringing a forest of connections out behind it.  One thing to note here is that this is the audio unit in the lower-end "SEL" trim and it may be slightly different in the higher trims, which have a separate amplifier.  But the basics are the same -- the various radio antennas arrive here, AM/FM, Sirius XM, GPS, and cell.

Audio unit apart, cell modem found The whole unit went on the bench for disassembly, and from this point it was surprisingly painless to do what I needed.  The unit manufacturer simply OEMs third-party modules and adapts them in; the daughterboard here carries the cell radio and the Sirius XM receiver.  The cell modem is at the lower right here, with its cover next to it.  Apparently made by "Continental", and designed for mobile applications -- it just plugs onto the daughterboard.  Often the thru-tabs on such shielded box covers are soldered in, but these weren't -- just twisted a little once through the holes to retain it in place, thus very easy to straighten and remove.  There's even an IMEI printed on the module, as well as on the label on the outside of the head unit.  No obvious SIM, but these things are probably implemented as an "eSIM" memory block inside which allows for remote provisioning.  Popular wisdom indicates that they're probably registered on some variant of Verizon data service.

Secondary cell-modem antenna under dash The cell unit has two antenna leads -- one goes up to the sharkfin antenna cluster on the roof, and one goes all of six inches to this little undocumented box under the dash next to the instrument cluster.  That's clearly the second cell antenna, for "diversity" or whatever.  Both antenna leads would now simply dangle now that their radio-side connectors were no longer present.
The cellular cancer was thus duly excised and the unit reassembled without it.  I toyed with the idea of leaving the entire daughterboard out, but decided to keep it in for a couple of reasons.  The Sirius stuff could stay in because that's receive-only and the car came with a free temporary subscription to mess with, but more importantly a connector carrying the P-CAN, the main bus for vehicle driving control, arrives via a connector on the daughterboard.  The head unit can display various running data about car operation and energy use, so I didn't want to potentially lose that functionality if a direct P-CAN connection was needed to see it.

Audio head option-programming resistor There's an amusing area on the daughterboard, apparently a single resistor for telling the unit what features are installed.  Evidently this one is programmed for "HD radio" and "modem" with 56K installed, but of course now no longer had a modem.  I figured that if I reinstalled the head unit and it started bitching constantly about not having cell communications, I could just crock in a 270K resistance here to de-option it if needed.

[I wonder how many of these come with a CD player anymore...]

However, the head unit went back into the car and seemed to work just fine afterward, with absolutely no warnings about a missing cell modem.  A day or two later the date/time setting got screwed up somehow and the icon to set it manually greyed out -- perhaps the default was to grab timestamps off the cell network and/or GPS?  Simply hard-resetting the head unit with the tiny recessed button set things right on that score, and there were no further issues.  Date/time confusion is apparently a fairly common problem on Hyundai/Kia head units anyway, and resetting it seems to be the fix.  I screwed around with the Sirius radio a little but found it of relatively little interest, and certainly had no intention of subscribing once the dealer freebie ran out.  My preferred audio while driving is what drifts into my open windows right and left, because it's all good input to the full-attention control process.

And guess what: pressing the BlueLink button on the rearview mirror now did absolutely nothing -- no lockup, no warnings, zip.  It was now a complete no-op with cell connectivity gone.  Solved *that* problem handily, we did...

  [ Up to EV index ]

_H*   191003