Retrofit CCS compatibility onto earlier (NA) Model 3 - DIY approach

[FalconFour]

New findings, new tests.

The thermistor grounds (pins 14, 18) are ground pins on the Gen4 board, despite not being present in the new (2020+) harness. So, compatibility is there.

The thermistors seem to just be reading +100f more than they should. In Tes-LAX, those numbers slowly increase, just as the charge port normally increases when charging. But the car doesn't seem to mind.

Supercharging works 100kW at 45% at a v3 station.
CHAdeMO adapter works the usual crap sandwich though, 44kW and station stopped with a fault, but that's the normal CHAdeMO experience (roll the dice).

I'm almost ready to button the car back up I replaced my 10k resistor wire with installing a 10k resistor directly onto the Gen4 board, between pins 5 and 14. So, that's actually quite clean. And since the thermistors already have good ground, that eliminates any need for harness tinkering.

So far, the fix to get Gen4 working (get rid of the "coverOpen" fault, where there is no cover sensor in the "Gen3" charge port) in a "Gen3 car" is just a 10k resistor between pins 5 and 14. As simple as that! And Gen4 now works in old cars.

Yep, that's it: to get CCS compatibility, buy a Gen4 charge port ECU (1537264-00-B for US/NA cars), pop it open, and install a 10k resistor between these pins:
View attachment 762037
(sorry, I didn't get a pic of the actual install I did... so I did my best miming attempt with a photo I had, and mirroring it )

Wait for an update to become available for your car, then de-energize the 12v, swap the ECU, power the car back up (as in that guide), and immediately apply the update -- if you don't immediately apply the update, the car will kill the 12v battery in a very short time (around an hour). When it comes back from the update, you should have no faults, and CCS support should be enabled!

Remember, you're reading advice out of a random internet forum, so responsibility falls on you, etc, etc, etc. Don't be stupid, and try to avoid breaking things. Being a jerk will only make people less likely to want to be helpful in the future. Being not-a-jerk encourages more openness and more cool things.

Bumping this to keep it at the top of the new page (for new passers-by: it's the current fix to get Gen4 on an old car!)

So if I'm understanding correctly, these thermistors are present on your existing port as well as (likely) on the newer charge port you have on order. However, they are reading 100F more than expected and likely giving you your nonfatal "thermistorIrrational" error.

I wonder if the newer port uses a different thermistor with a different resistance curve. My concern would be that in typical Tesla fashion Tesla makes this nonfatal error fatal after a later firmware update. I wonder if it's possible to tune the curve in some way to get into a the proper temperature range...

Yep, it's a bit odd... my idea for the future is to try and hunt down the difference on the new port, see if it's (for example) a 10k vs a 100k or something like that, and maybe make a converter harness with a parallel resistor to drag the base resistance down (or in series, if it's higher). No idea if that'd work. That part is a bit funky. In a thermistor circuit, there's normally a base pull-up resistor, then the thermistor acts as a varying pull-down, which changes the voltage and supplies the temperature reading. If the pull-up is different, hmm. That'd do it. It just leaves me wondering why Tesla would leave so much of it the same, claim it's compatible, then go and change something that significant (and unnecessary?).

 

[Xelloss99]

Bumping this to keep it at the top of the new page (for new passers-by: it's the current fix to get Gen4 on an old car!)


Yep, it's a bit odd... my idea for the future is to try and hunt down the difference on the new port, see if it's (for example) a 10k vs a 100k or something like that, and maybe make a converter harness with a parallel resistor to drag the base resistance down (or in series, if it's higher). No idea if that'd work. That part is a bit funky. In a thermistor circuit, there's normally a base pull-up resistor, then the thermistor acts as a varying pull-down, which changes the voltage and supplies the temperature reading. If the pull-up is different, hmm. That'd do it. It just leaves me wondering why Tesla would leave so much of it the same, claim it's compatible, then go and change something that significant (and unnecessary?).

Sounds like Tesla could revise the firmware to use the Gen 4 on older Model 3 with the same ECU without any hardware mods or special versions.
Don't error out on INLET_1_CONTINUITY and instead use it as a version sense jumper at least on North American vehicles without the second GB/T inlet.
If it's "On" it's a new car and act regularly.
If it's "Off", it's an old car, and change the thermistor calculation formula to accommodate the old thermistors.

Of course, it actually requires Tesla to do this.

Good work on your testing/experimentation! Makes a lot of us more at ease that it is possible even if Tesla doesn't offer a retrofit or drags their feet.

 

[Xelloss99]

Another thought/remark:

Gen 3 has no heater output on pin 1 (INLET_1_HEATER_OUT), while Gen 4 does. Thus a heated charge port must mean a Gen 4 compatible harness and charge port is installed.

This is visually identifiable from outside the car by looking at the lighted Tesla logo on the charge port.

If your logo is centred on the hinge, it's an unheated port and you have a Gen 3 ECU which will need either these mods done, or to wait for a Tesla retrofit option.
If your logo is not centred on the hinge, it's a heated port, and *should* be compatible with the Gen 4 ECU upgrade if your car doesn't already show that CCS is enabled.

Abstract Ocean's charge port wrap page has an example of what to look for to determine if you have a heated (Gen 4) or non-heated (Gen 3) port.

Vinyl Charging Port Wrap for Model 3 & Y

Add a little class to your Model 3 or Y charging port by wrapping it with one of our vinyl decals.

abstractocean.com

 

[ehendrix]

So far, the fix to get Gen4 working (get rid of the "coverOpen" fault, where there is no cover sensor in the "Gen3" charge port) in a "Gen3 car" is just a 10k resistor between pins 5 and 14. As simple as that! And Gen4 now works in old cars.

Yep, that's it: to get CCS compatibility, buy a Gen4 charge port ECU (1537264-00-B for US/NA cars), pop it open, and install a 10k resistor between these pins:

Silly question for you mainly cause I'm not an electronics/electricity guy and just wondering. So you solder a 10K resistor pin between those 2 then?

 

[FalconFour]

Silly question for you mainly cause I'm not an electronics/electricity guy and just wondering. So you solder a 10K resistor pin between those 2 then?

At the moment, yuppppp. That's all there is to it. For mine, I put it on the back of the board (the only place that has space), and clipped out a tiny bit of excess case plastic it'd be getting in the way of. I've got an order with Digi-Key to potentially come up with a solderless solution (creating a jumper wire with resistor between pins 5 and 13, both unpopulated in the Gen3 harness so an easy slide-in fix). That makes Gen4 happy to work on the old cars, as everything else clicks right together (firmware and hardware-wise).

 

[Timbo2]

One thing. I wonder if 60 ohms works and is the ideal value.

This is for the high voltage safety on the Model S

https://static.nhtsa.gov/odi/tsbs/2014/SB-10052449-4313.pdf

 

[FalconFour]

One thing. I wonder if 60 ohms works and is the ideal value.

This is for the high voltage safety on the Model S

https://static.nhtsa.gov/odi/tsbs/2014/SB-10052449-4313.pdf

That's an interesting, but ancient, document (June 2013). Long before the Model 3, and long before the added cover on the 3. Those 60 ohm jumpers seem unrelated... that's HVIL but I don't think this has relation to HVIL (it's resistor to ground, not resistor in loop).

Does make me want to get my hands on that Tesla Diagnostic System (TDS) software though But I imagine that's all Toolbox, now...

 

[FalconFour]

Did a longer charge (16% to intended 24%) today at a 250kW Supercharger. I wasn't preconditioned that long (20min drive on freeway) and saw 180kW max I think, but then... this came up about 2 minutes in (at about 20%).

hmm. That thermistor error may not be as benign as I'd hoped. It read 167f by the time I got the darn Tes-LAX setup running (takes a lot of fiddling; manual connection & app wrestling), but I suspect maybe it faulted at 170f? Hmm. Top two faults are just the BMS saying "Hey, the charge port has a fault, so I do too". I suspect the 3rd fault is also a "following" fault. The 4th one is probably the main fault. And because I wasn't in service mode, I can't see the hidden (real) fault codes.

It restarted fine and I got the 24%, though.

I'm hopefully getting my hands on a CCS1-to-Tesla adapter (EVhub one) tomorrow, and this kinda foreshadows the issues I may encounter there. Fixing the thermistor issue may end up being critical to making it work properly.

 

[CubedRoot]

Hey @FalconFour Would you mind sharing the part number for the Chargeport you ordered? I had my 2018 model 3 chargeport replaced completely about 5 months ago because the door was wonky. I'd like to see if I got a newer version. They installed part number 1566302-00-A for my charge port.

 

[FalconFour]

Hey @FalconFour Would you mind sharing the part number for the Chargeport you ordered? I had my 2018 model 3 chargeport replaced completely about 5 months ago because the door was wonky. I'd like to see if I got a newer version. They installed part number 1566302-00-A for my charge port.

Interesting. The P/N I was given to have ordered is 1449495-10-E.

A quick Google shows that the part number you have is for the door mechanism, not the port itself. So, maybe they just replaced the door? Is that the only P/N on your invoice/estimate?

Also, the images I'm finding of P/N 1449495-10-E are not quite looking like what I have... particularly, the covers are all black, not orange like mine. And the thermistor wires aren't visible poking out of the cover, as they're poking out of the cover on my port. Iiiinteresting.

New P/N 1449495-10-E (I don't have yet - image from eBay):

My P/N 1093010-00-? (I think it was E when I was at the car, didn't realize the photo blocked it):

More fuel for the theory that the charge port is different within the "SOP through Oct 2020" (Gen3) family.

 

[CubedRoot]

Looking over my invoices thats the only part number they included in that section. I was also getting the PCS replaced as it was only charging at 32amps so theres a good bit of part numbers scattered on this invoice. The notes however say the chargeport door and chargeport assembly were replaced. Really odd that.

 

[MLXXXp]

Gen 3 has no heater output on pin 1 (INLET_1_HEATER_OUT), while Gen 4 does. Thus a heated charge port must mean a Gen 4 compatible harness and charge port is installed.

This is visually identifiable from outside the car by looking at the lighted Tesla logo on the charge port.

If your logo is centred on the hinge, it's an unheated port and you have a Gen 3 ECU which will need either these mods done, or to wait for a Tesla retrofit option.
If your logo is not centred on the hinge, it's a heated port, and *should* be compatible with the Gen 4 ECU upgrade if your car doesn't already show that CCS is enabled.

I have a May 2021 build M3 LR. The "Additional vehicle information" shows "CCS adapter support: Enabled". The lighted Tesla logo on my charge port is close to centred, like the Abstract Ocean photo of a NOT heated port.

So, do I have a Gen 4 ECU but an unheated charge port? Would a M3 built in mid 2021 have an unheated port?

Here's a photo of my car's charge port logo and hinge:

 

[Bunklung]

I have a May 2021 build M3 LR. The "Additional vehicle information" shows "CCS adapter support: Enabled". The lighted Tesla logo on my charge port is close to centred, like the Abstract Ocean photo of a NOT heated port.

So, do I have a Gen 4 ECU but an unheated charge port? Would a M3 built in mid 2021 have an unheated port?

Here's a photo of my car's charge port logo and hinge:
View attachment 765061

It's right in the link that @Xelloss99 posted.

 

[MLXXXp]

It's right in the link that @Xelloss99 posted.

But @Xelloss99 also said:

If your logo is centred on the hinge, it's an unheated port and you have a Gen 3 ECU which will need either these mods done, or to wait for a Tesla retrofit option.

So does that mean I have a Gen 3 ECU that supports the Tesla CCS1 adapter?

 

[FalconFour]

Wow, there are a lot of variations...

I can say for sure that Oct-2020 was the switchover to Gen4. That's the "line in the sand" drawn by Tesla service info - the dates assigned to the wiring diagrams have "Oct-2020 to present" as one group, while other various scattered dates prior to that have the same wiring for the charge port among them.

Possible that your May-2021 car was built with an earlier outer shell, maybe without heating, ... maybe?

All just guesses, because this is one wild conflict. I'll have to look at my (3) coworkers' other newer Teslas (3 and Y)... what trend have I started

 

[Bunklung]

But @Xelloss99 also said:

So does that mean I have a Gen 3 ECU that supports the Tesla CCS1 adapter?

Okay, sorry. I thought you were caught up on what is a heated port.

As far as the ECU, I think you are suggesting that maybe there is an ECU3 WITH a PLC chip? I keep thinking that Tesla says the ECU 4 SHOULD work with @FalconFour's 2018. That pulls me back to the idea that his car has a hardware issue. It would create a plot twist here if there is another ECU at play.

 

[Xelloss99]

Okay, sorry. I thought you were caught up on what is a heated port.

As far as the ECU, I think you are suggesting that maybe there is an ECU3 WITH a PLC chip? I keep thinking that Tesla says the ECU 4 SHOULD work with @FalconFour's 2018. That pulls me back to the idea that his car has a hardware issue. It would create a plot twist here if there is another ECU at play.

I would be inclined to think that it is simpler than that and that it is a second rev of the heated port which happens to have the logo in the same position as the original non-heated port, with the harness and ECU being Gen 4 with PLC, which if this is the case would invalidate the logo position theory.

 

[Bunklung]

I would be inclined to think that it is simpler than that and that it is a second rev of the heated port which happens to have the logo in the same position as the original non-heated port, with the harness and ECU being Gen 4 with PLC, which if this is the case would invalidate the logo position theory.

My car was Sept 21 and the logo is in the center. My car was iced up this morning and set it to defrost. I am 99% sure it's not a heated charge port. *Update* Yeah, it's offset, the logo, but it doesn't seem to heat anything. maybe it only heats when charging?

My car also doesn't have the PLC chip.

 

[android04]

My car was Sept 21 and the logo is in the center. My car was iced up this morning and set it to defrost. I am 99% sure it's not a heated charge port. *Update* Yeah, it's offset, the logo, but it doesn't seem to heat anything. maybe it only heats when charging?

My car also doesn't have the PLC chip.

The heated part would be the inside of the port. Tesla added that after some people with earlier cars had issues where the charging plug would freeze in the charge port and they couldn't remove it. Snow or ice would melt and flow around the pin that locks the charge plug to the car, and would refreeze later on. Tesla pushed a software update that disengaged the locking pin if temps were below freezing and the car was done charging. In other situations (babe remember exactly which ones) the car clicks the lock pin in and out every second, probably to keep it from freezing.

 

[MLXXXp]

I would be inclined to think that it is simpler than that and that it is a second rev of the heated port which happens to have the logo in the same position as the original non-heated port, with the harness and ECU being Gen 4 with PLC, which if this is the case would invalidate the logo position theory.

After experimenting, I'm pretty sure that my M3's charge port, with a centred logo, is indeed heated. Here's how I tested it:

I used a Pax Instruments T400 thermometer with a type K thermocouple that can settle on the current temperature within a few seconds. (See attached photo.)

• The temperature in my garage where I park my M3 was about -2C (28.4F)
• I unlocked the car, so I could open the charge port, and left the climate control system off.
• I opened the charge port. The temperature just outside the port was about -1.5C (29.3F).
• The back bottom of the charge port was at about -0.5C (31.1F) and remained at that temperature until a timeout automatically closed the port after a few minutes.
• I then turned on the rear window defroster (which, according to the manual, also turns on the charge port heater) and turned off the rest of the climate control system.
• I opened the port again. The temperature just outside the port was still about -1.5C (29.3F) but the same spot at the back bottom of the port quickly increased to over 11C (51.8F) in less than a minute.