Retrospective thread-summary pseudo-wiki for quick access:​

What is it?​

“Gee, I wish my Tesla, despite having access to the country’s biggest quick charging network, could also charge on stations made for Other EVs too”. Said no-one ever. Except… well, there are use cases for it. And with Tesla now teasing “CCS adapter support” in the car, I originally wanted to get ahead of the curve and upgrade my charge port ECU. It turns out that, while backwards compatibility SEEMS to be baked into the hardware design, something doesn’t quite mesh properly. I set out to figure out what. The solution is to make your old charge port (“Gen3”) act and feel like a Gen4 charge port, for the Gen4 charge port ECU, which supports CCS.

Does this apply to my car?​

If your car is built prior to Oct 2020, yes. If it’s built after Oct 2020, check for “CCS adapter support” in the Additional Vehicle Information under the Software tab of the car settings page. If it’s “Not Installed” (and post-Oct 2020), then chances are, you have a Gen4 charge port and a “stripped” ECU. You can simply replace the stripped Gen4 (P/N 1537264-80-B) with an un-stripped full version (1537264-00-B), and ignore the rest of this fluff and hooplah about something called “A Bundle of Wires”. Everyone else, listen up.

Where do I get the ECU?​

It’s become a bit of an art. Don’t be a Karen or Ken and your chances are better. At the moment they likely have mostly “-80-” ECUs (stripped – do not buy), but some SCs may still have “-00-” ECUs on hand. Be nice and expect a bit of a struggle (as of May 2022) to find one.

You can get the ECU “by name” by contacting Tesla Service one of two ways: one (the way I did it) was just to wander into a service center and ask for a part at the counter. Two (I’ve tried, and it worked – but with a little confusion as parts ordering doesn’t seem to be a common ask), is to “schedule service” as “other”, and explain what you want to order. The part number is “1537264-00-B” for the Gen4 ECU (for North America at least).

And the Bundle of Wires?​

As far as the wiring adapter (2017-Oct 2020) goes (the result of this thread so far), there’s a friendly neighborhood eBay seller with a similar bird’s name and a bag over his head saying “definitely not a bird”, selling a little thing called “A bundle of wires with crimps“. Search around for it on the Google – you’ll find it!

There’s also now a second source supplying these Bundles of Wires – search for “2muchsun adapter” and head over to their website’s Products page to find it! Same price, different source – share the love.

As to why on earth it’s called “A bundle of wires”…? The threat of Karens and Kens that make everyone’s days bad.

It’s not available. Can I build my own?​

Sure. Here’s a complete shopping list!

What does A Bundle of Wires with Crimps do, exactly?​

The Gen4 charge port was redesigned to use a PCB (printed circuit board) on the charge port for its low-voltage connections, port heating, and thermal sensors. The original (Gen3) port just has individual sensors and wires placed around the port, all coming to one connector. In the process of redesigning it, they also needed a cover to protect against exposure to the high-voltage terminals on the new port (not present/needed on the old, fully enclosed port – no HV is exposed anywhere in this process). They changed the thermal sensors’ values a fair bit, as well. So, the adapter:

• adds a little resistance to the existing 10k thermistors, and since the mapping can’t be made to match 1:1, it places them in an electrical position that aligns with overheat protection, but otherwise always seems hotter than it really is. It’s slightly skewed towards being overly cautious. It’s designed to align “real vs. measured temp” at about 160f. That means it definitely won’t allow your port to melt, and preserves safety.
• moves those thermal sensors from Therm1 & Therm2 (Gen3) to Therm1 & Therm3 (Gen4)
• adds a 47k pull-down resistor to satisfy the “high voltage port cover” present on the Gen4 port
• adds a 2.7k pull-down resistor to the prox line to replace the resistor that changed places from Gen3 to Gen4
• groups all the grounds together (for therm & signal) just like Gen4 does using the PCB

How do I build it?​

Follow the photos in this post, which follow the wiring diagram in this post (my “final answer” so far). Note that the pin numbers are shown on the connector housings… in fairly small print. Look at the photos throughout that page for help. Note that there’s a terminal lock on each connector (press both sides to activate… screwdriver in and pry up both sides to de-activate). Care is taken not to activate it before shipping so hopefully it arrives “open” and you can slide pins into it properly.

How do I install it?​

Welp, can confirm the old port doesn’t have a resistor on Prox. Lame. Well, good news is, the Prox signal was split in 2 pins (copied/shorted to both) probably for this very reason (and Gen3 has 2.7k between the Prox pin and Gnd). So I just have to add the resistor that changed places, now we…

teslamotorsclub.com

BYO “getting into the area and pulling the ECU out” though. Involves some minor trunk-liner-pulling. Relatively easy 10-minute job if familiar, perhaps 30 if not.

Great, where do I get the adapter itself, then?​

Two options I know of:
– Tesla Korea has been shipping a NA-compatible CCS adapter for a while now. It’s robust and I like it a lot. It’s a pass-thru adapter, so there’s no logic in it, and no way to know it’s Korean or not. Just like the J1772 adapter, the car can’t even tell you have it plugged in (thus obviously not from where you got it). If you get it, you’ve got it. Try these guys as a forwarder-shopping service: Get your Tesla’s CCS1 Adapter From Korea! – they’ve helped a lot of people get CCS adapters. They do need your Tesla account login to do it, though (you can change it after shopping, to be safe), because Tesla only sells one adapter per person.
– EVHub, a friendly Ukranian company (woo ), has a NA-compatible CCS adapter as well. This is what I have. It’s robust and I like it. It’s basically a CNC’d copy of the Tesla Korea adapter, electrically. Find that adapter here: Tesla US CCS1/CCS2 (400A)
See discussions here:

Given that the Model 3 now supports the CHAdeMO adapter, is the idea of a CCS adapter dead? I would love to get a CCS adapter that was smaller, cheaper and supports 150kW for my 3, spending $600CAD on a CHAdeMO that is huge and only supports 50kW seems to be a waste. Are Tesla working on a CCS…

teslamotorsclub.com

And now, the original post:

Anticipating the release of the CCS(1)-to-Tesla adapter, I’m looking into getting my car ready for it. Already aware of the Gen4 ECU, I started digging in.

So far, I found the Gen4 Charge Port ECU is really the only part needing to be swapped. It’s already present in Model 3 and Y starting at an unknown date (to me) – some time in 2020 I think was when the Gen4 started being the standard part for both cars. If it is, your “Additional Vehicle Info” after the holiday update should show CCS as being “Enabled”. The Gen4 ECU contains a CCS PLC modem (relay, transformer, and a Qualcomm PLC chip) that enables the RF-frequency Ethernet interface to ride over the top of analog +/-12v J1772 for DC charging.

Here’s where I stand: I walked into a Tesla service center, laid out my low expectations (I was expecting to have to eBay it, but thought it was worth a try), and asked about the specific part number: 1537264. They looked it up, found it, and initially grabbed the part for EU spec (I think that one was “1537264-20-B”). Quickly found the mistake (none were in stock), found the NA part number (1537264-00-B), and found one in stock. I bought it then and there, over the counter, no problem. Amazing.

All this info can be found on the Tesla EPC here: Parts Catalog — to access it, go to the link once, sign in with your Tesla account, then close the tab, come back here, click it again – it’ll zero-in on exactly the page that way.

Swapping it was super easy – well, after you go through the hassle of ripping your trunk lining apart to access it (yuck, sticky sealant goop in the trunk gasket). Once you get the lining peeled back around the charge port area, the ECU is right there… big bright red LED (on the old version), held in with 1 screw. I powered-down the car (12v negative pull; contactor plug release, “CLUNK”) before I unplugged/started messing. Swapped it, plugged it back in, booted up… “baap-baap-baap”… some alert. I expected that. When you swap an ECU, it needs to be reflashed, which is what an update does. I anticipated the holiday update and I also charged to 100% just in case it didn’t come or I had issues. Well, it came, but I had issues

There were 3 errors stacked together: “software update required (schedule service)”, “Unable to charge – Service is required (Charge port component is not detected)”, and “Unable to charge (disconnect and retry)”. Before the update, it would even refuse to shift to D until I confirm an unusual message saying that it REALLY thinks the charge cable is connected, but it can’t be sure… so I tap a button saying “charge cable is unplugged”. I kinda expected all this.

What I wasn’t expecting, though, is the holiday update not fixing everything. It took care of the “software update required”, but I was left with 2 of the 3 messages, and could drive normally again… though charge port would open weirdly (and slam abruptly when closed), wouldn’t unlock, and obviously wouldn’t charge. I drove to a Tesla service center and dove into Service Mode, where I found a more detailed description of the problem:

CP_a109_thermistorIrrational and CP_a009_coverOpen. Strange. I like that it has rationality checks for the thermistor lots of devices don’t, happily report -300c or 1672c or something. haha. Anyway, that’s an odd error, no? Also, the coverOpen fault — its message states that the cover can’t be confirmed closed for some reason (sadly I didn’t take a photo of that one expanded). That’s also fairly odd.

This is where I sit today (still at 80% SOC and no plans, so I’ve got a while to figure it out. haha). I still have the original ECU I can swap in, in worst case, but I hope it doesn’t come to that.

At the SC where I parked to get Service Mode, they weren’t busy, so I poked my head in and – first confessing that I don’t expect miracles since this is DIY – I asked if they knew anything about it. Indeed, they say, the Gen4 ECU should be compatible, and it should be a drop-in. Said that an “update” doesn’t always contain all firmware, so they staged a “full reflash” to my car to see if that’d fix it. Sadly, it didn’t (no change). After that, they say, schedule service for further digging. I don’t quite want to bug them yet, but tomorrow I plan to go out and take a deeper look into the hardware for any potential issues (like, maybe the other end of a cable came loose when I was fiddling wires? Seems unlikely, but hmm).

At least my CCS adapter support is now “enabled”

That’s where I’m at, and I just wanted to get this thread rolling! I really wanted to find any info about this charge port ECU, perhaps its pinout, or anyone else with a similar DIY-upgrade experience… couldn’t find anything on search. So, something now exists!