How to enable CCS1 adapter/NACS support on older Model 3/Ys now without waiting for Tesla

In order to use non-Tesla DC fast chargers from networks such as Electrify America or ChargePoint, your older Model 3/Y will still need to have CCS enabled (i.e. DIY retrofit) regardless if the plug is NACS or CCS1. Only difference is the CCS1 Adapter is not needed if it is a NACS plug. This is because the communication behind the NACS plug is still CCS (PLC) and not Tesla (SWCAN). This is mentioned in section 4.5 of the Tesla NACS Technical Specifications document.

This easy DIY retrofit will allow you to buy the CCS1 adapter sooner from the Tesla store and can save potentially at least $230 in parts and labor according to a recent Tesla estimate for a Tesla Model S/X CCS1 retrofit ($450 for parts and about $145 for labor).

There are 2 types of DIY retrofits for the Model 3/Y either A or B. Estimated install time: 10 minutes - Level of difficulty: Easy

Retrofit A. Potential Savings: $280. If your EV is a North American (NA) Model 3 and made AFTER October 4, 2020 (built with black trim, heat pump and refreshed dash) or a NA Model Y, all you need to do is swap out the charge port controller (ECU) to the full-featured Gen4 ECU which is Tesla part number 1537264-00-B.

1. Purchase 1537264-00-B from a Tesla Service Center for $140 + sales tax. This is not a restricted part so there is no reason why you shouldn't be able to purchase it. You may need to be assertive.

2. Remove your existing ECU and install the new one (see this video on how to swap out @7:27). Per the service manual, there is no need to disconnect any power (12V or main traction).

3. You will need a software update or software reload before the new ECU can work. The easiest way is to do a software reload via the service mode menu (select the car icon, then software and touch the Model 3 or Y text and hold a few seconds until you see a quick flash, release and the password entry should appear. Password is service).

Retrofit B. Potential Savings: $230. If your EV is a NA Model 3 and made BEFORE October 5, 2020 (built with chrome trim), all you need to do is swap out the charge port controller (ECU) to the Gen4 ECU which is Tesla part number 1537264-00-B and add a third party wire harness called "A Bundle of Wires with a Board" in line with the Gen4 ECU.

1. Purchase 1537264-00-B from a Tesla Service Center for $140 + sales tax. This is not a restricted part so there is no reason why you shouldn't be able to purchase it. You may need to be assertive.

2. Purchase "A Bundle of Wires with a Board" less than $50 either here or on Ebay or you can build your own with instructions in this post.

3. Remove your older Gen3 ECU and install the new one along with "A Bundle of Wires with a Board"(see this video on how to swap out @7:27). Per the service manual, there is no need to disconnect any power (12V or HV).

4. You will need a software update or software reload before the new ECU can work. The easiest way is to do a software reload via the service mode menu (select the car icon, then software and touch the Model 3 or Y text and hold a few seconds until you see a quick flash, release and the password entry should appear. Password is service).

NOTES:

1. The service manual recommends reinstalling the software as soon as possible to prevent excess drain on the battery.

2. Once your EV support the CCS1 adapter, you may want to buy the actual CCS1 adapter ($175) from the Tesla store in order to use DC fast chargers that do not have the NACS plugs. You might need to wait a day before ordering so that the store is updated with change in CCS adapter support status to allow you to buy it.

3. For support and questions, check out the Community Forum.

Q: Is this retrofit still needed for non-Tesla DC fast chargers with the NACS plug?

A: Yes. Behind the NACS plug is still CCS so your Model 3/Y will still need to be CCS enabled in order to communicate to any non-Tesla DC fast charger.

Q: Are these safe retrofits?

A: Yes. Both retrofits use Tesla's Gen4 ECU and there has been over 1000 "A Bundle of Wires" sold in the last 18 months without any confirmed problems or charging limitations due to the retrofit. Since there are no high voltage or high current circuits in the ECU, it is not necessary to touch any of the high voltage or high current components (including the thick orange wires) in either retrofits, making it completely safe for a DIY project. In fact, the Tesla service manual doesn't require the vehicle to be powered down or 12V disconnected when swapping out the ECU.

Here are some detailed reasons why this is a safe retrofit:

The Gen4 ECU supports the CCS protocol plus some Gen4 charge port hardware specific features (port heater, an internal cover, different thermistor type, and built in proximity resistor). The Gen4 charge port hardware is installed in all the Model Ys and Model 3s built after Oct 4, 2020 while the older Model 3s (built before Oct 5, 2020) use the Gen3 charge port hardware.

The Gen4 ECU and Gen4 charge port hardware were orginally released together to support CCS but due to some supply chain issues, Tesla made a version of the Gen4 ECU (1537264-80-B) without the CCS support and started using those whenever they needed to deliver cars but didn't have enough of the fully populated Gen4 ECUs. This is why the Retrofit A is so safe and is as Tesla designed and released.

However, Retrofit B is a little more challenging because it reuses the Gen3 charge port hardware by using "A Bundle of Wires with a Board" to feed the proper signals into the Gen4 ECU by remapping matching wires and adding 4 resistors. The resistors help tune the low voltage logic level signals to be similar or equivalent to the expected signals and allow the Gen4 ECU to work properly with the Gen3 charge port hardware.

Q: Does this void my warranty?

A: The technical answer is no. However, if you have a failure in the charge port, Tesla could claim it is not covered because of the added board and wires with the Gen4 charge port ECU, but Tesla will need to provide backup.

In the US, the Magnuson-Moss Warranty Act prohibits product manufacturers like Tesla from conditioning consumer warranties on the use of any original equipment part or service. Furthermore, a manufacturer can only deny warranty coverage if it can demonstrate that a non-original equipment part or related service caused a defect to occur in the original product. In other words, they can't just say it but rather have the burden of proof. The schematics to this retrofit is publicly readily available. Anyone who is in the trade can do the analysis and will conclude this retrofit is safe and 100% compatible with the existing design. The analysis shows that this retrofit is extremely unlikely to cause any damage if correctly or incorrectly installed or even if there was a quality defect. There is also over 18 months of additional real world use data out there with over 1000 retrofits with no issues caused by this retrofit.

In addition, troubleshooting is easy because this modification is fully and easily reversible without leaving any physical signs that it was ever done. So if you have a charge port failure, reverse the retrofit (reinstall your original ECU, remove "A Bundle of Wires ...", if applicable, and reinstall the software) and if it still doesn't work then it's not the retrofit causing the failure.

Q: Will this retrofit allow me to still use Superchargers and CHAdeMO adapters?

A: Yes, this retrofit will not reduce or remove any existing charging options already available on your vehicle.

Q: Should I wait until Tesla offers an official retrofit?

A: Probably not. Tesla already missed both estimated release dates for their official retrofit without giving a new estimate. Word on the street is they may not release one since this DIY retrofit works so well and is cheaper than what they can offer. Others are thinking the recent NACS announcements may have shifted Tesla's priority to releasing NACS support for other OEMs. While others are thinking Tesla is more focused on selling new cars and less on retrofits. Whatever the reasons are for the delay, you should go ahead not depend on Tesla. The DIY retrofit will future proof your car, give you more options and reduce range anxiety by knowing you can charge at any DC fast charger in North America.

Q: Will I have buyer's remorse if I buy this solution for my older Model 3?

A: No. Most of the cost is for the Tesla Gen4 ECU ($140). You will need some variation of this ECU anyways even if Tesla releases their retrofit. We designed the retrofit to be easy to install with quality parts that meet or exceed OEM specs. We believe you will be completely satisfied because it has works so well (as mentioned in all the reviews). We also know because we have it on our older Tesla Model 3s for over a year and half with zero issues!

Q: It says it is a DIY solution. What does this mean?

A: You will need to install this yourself as this not a Tesla offered solution. It is as easy as changing out a battery or tire, but a lot less work.

For Retrofit B, for example, you will need a 10 mm socket wrench and a screw driver or trim fastener removal tool. Remove 2 fasteners on the trunk trim, pry open the carpeting behind the charge port while disconnecting the trunk light, unscrew 1 bolt holding old ECU, install new ECU along with "A Bundle of Wires with a Board", reassemble in reverse, and reload software. It should take less than 1 hour including the 20-30 minute software reload.

If you want to know more details on Retrofit B, you just need to read the first post in this long TMC topic.