Another failed Model 3 (2019) CCS upgrade

[woolfe]

This is a similar report to someone else who recently posted about an attempted CCS upgrade on their 2017 Model 3 that required a thermistor remapping (bundle of wires) change as well.

The installation for me went super smooth and the car was able to charge over AC just fine after the swapout + software reinstall. It was even able to urban supercharge just fine the day after as well. However, things went a little sideways on my recent roadtrip. My experience mirrors the above linked post very closely.

So far the pattern is such: on the first supercharge on a coldish day (sub 30F), with a low state of charge, at a 250kW charger, my car will kill the charging session 5-10 minutes in with the following errors:

• CP_a110 (CP_a110_thermalVelocityHigh: the charge port (CP) electronic control unit (ECU) detects an unexpected rapid rise in temperature)
• CP_a140
• BMS_a063
• BMS_a174

Spoiler: Images

My guess is the thermistors in my car are atypical to those in other models out in the wild, and, as a result, are tripping up the new Gen4 ECU. These errors usually only happen once, and I can restart the session by unplugging/replugging and things continue to work fine. Subsequent charges for the day (i.e. a roadtrip) work just fine with no errors. My other guess is that the charge port is already warm enough that the strong curve seen on the initial charge doesn't show up anymore.

Oh well. While it seems like I can push through these errors and gain CCS support, I'd rather not have to deal with the headache, especially since it's an unknown issue and could impact me with other charging sessions (or, continue not working when I restart the charging session). Looks like I'll be waiting for the official retrofit in the near future.

 

[buckets0fun]

Official retrofit is available via https://shop.tesla.com/product/ccs-combo-1-adapter
450 for the retrofit and adaptor.

 

[woolfe]

Official retrofit is available via https://shop.tesla.com/product/ccs-combo-1-adapter
450 for the retrofit and adaptor.

Thanks! I’m impatient, which is why I attempted this after Tesla delayed the 3/Y retrofit into mid-23.

 

[gsmith123]

These reports make me mildly anxious about the retrofit I just did.

So far it's working fine though.

I tried to thermally stress test it today to make sure I don't have this problem. In 31 deg F weather (after letting the car sit outside overnight) I charged on a V3 SC and hit ~200kW peak speeds. Didn't precondition enough to hit full 250 kW unfortunately (to induce quickest charge port heating) but hopefully I got close enough.

No issues at all so hopefully that means I'm good to go. At least it sounds like when this problem does pop up it's not likely to leave one stranded.

 

[woolfe]

These reports make me mildly anxious about the retrofit I just did.

So far it's working fine though.

I tried to thermally stress test it today to make sure I don't have this problem. In 31 deg F weather (after letting the car sit outside overnight) I charged on a V3 SC and hit ~200kW peak speeds. Didn't precondition enough to hit full 250 kW unfortunately (to induce quickest charge port heating) but hopefully I got close enough.

No issues at all so hopefully that means I'm good to go. At least it sounds like when this problem does pop up it's not likely to leave one stranded.

So far it's been working fine for me too — I've stuck on the Gen4 with the adaptor and haven't had an issue again. But we're dropping temps — I just supercharged with a coldsoaked pack at 45F and didn't have an issue (although I only hit 130kW/250kW max since the cold)


I figured it's not too annoying to have to deal with, and having CCS access has already saved me twice in road trips. Money well spent.

 

[woolfe]

Posted too soon, just got the thermal velocity error this morning — it was 37° out. I will be spending some time debugging this issue further.

 

[davewill]

Posted too soon, just got the thermal velocity error this morning — it was 37° out. I will be spending some time debugging this issue further.

It's not surprising. The bundle of wires is a hack. The added resistors bring the thermistor values into range so that it doesn't error out in most usual situations and DOES error out when the temp gets too high. It's not possible to make the controller see correct resistance values for the entire temperature range without actually replacing the thermistors inside the inlet (or the inlet itself), so having errors at the low end, especially an error that complains about the RATE the temp changes may be unavoidable.

 

[gsmith123]

I've tried to stress test mine as much as possible, with V3 SC sessions starting at 10-15% with ample preconditioning (so it'll ramp up to 250+kW as quickly as possible) and avoided warming up the charge port before hand.

No issues so far!

If there are any problems, it'll be from an absolute worst case scenario where the car immediately pulls max current (at least 670A, maybe a little past 700) in very cold weather.

CCS adapter charging working just fine too (but have only tested it to 135kW)

 

[woolfe]

It's not surprising. The bundle of wires is a hack. The added resistors bring the thermistor values into range so that it doesn't error out in most usual situations and DOES error out when the temp gets too high. It's not possible to make the controller see correct resistance values for the entire temperature range without actually replacing the thermistors inside the inlet (or the inlet itself), so having errors at the low end, especially an error that complains about the RATE the temp changes may be unavoidable.

I had a conversation with Falcon about this last year and he seemed to believe that, because the thermistors in the BoW are clamping values, the crushed range of temperature reported is actually lower than the real value. The end result should be the total rate of temp change is lower than the real rate, therefore preventing this possibility.

My issue is that I can’t get my canbus reader to get me the DC pin temp values. I don’t see cp_PinTemperature{1,2,3} values anywhere during my capture of a supercharge session. I’m using an OBDLink MX, so while it does drop packets occasionally I would expect some value to come through eventually. Either my DBC is outdated or these values aren’t reported on the bus that I tap into? (rear HVAC)

 

[Frank.The.Tank]

Just chiming in as a +1, I'm in the same boat and got this twice this weekend while supercharging.

I had no trouble in >100°F weather this summer, but now that it's near freezing I'm seeing this. A replug got me going both times but it's not super compelling a risk to take.

 

[woolfe]

Just chiming in as a +1, I'm in the same boat and got this twice this weekend while supercharging.

I had no trouble in >100°F weather this summer, but now that it's near freezing I'm seeing this. A replug got me going both times but it's not super compelling a risk to take.

Sorry that you're also experiencing this issue; but now I have a buddy

I misplaced my Gen3 controller so I can't even go back now. I'm still poking around to see if I can find a solution.

 

[woolfe]

I purchased a new bundle of wires and going to see if this solves anything. Made doubly-sure that the connections are tight and everything is installed properly.

It’s a bit warm in NYC right now. Will post results next time it dips below freezing.

 

[woolfe]

Today was mild, about 40F. Charged from 4% to 80% (peaked at 250kw) without issue. I’ll post again when it’s below freezing to see if it persists. Maybe my original BoW was bad?

 

[woolfe]

I charged today from 4% to 80% with a hot pack but cold (sub freezing) body and it unfortunately errored out again today. This is despite buying a new bundle of wires and ensuring the connections were snug.

Oh well. I did notice that the service menu in the holiday update now lists the DC pin temperature, so next time I’ll record that to create a graph, as I can’t get these values over CAN.

 

[woolfe]

My last update on this endeavor is that I’m rolling back to Gen3. I don’t home charge, so I supercharge all the time and I’m getting tired of having to sit around for the first 10 minutes to ensure my charge goes smoothly.

I’ll keep my Gen4 ECU for now, and maybe Tesla will eventually retrofit Model 3s; seems like it’s taking forever.

 

[Frank.The.Tank]

Woolfe, what's the best way to get in touch with Falcon? I'm an embedded systems engineer who'd be happy to help solve this with a small microcontroller with a DAC/ADC pair and some signal processing on a new bundle of wires board revision, but I'd love to work with Falcon on that rather than do my own thing.

 

[buckets0fun]

Woolfe, what's the best way to get in touch with Falcon? I'm an embedded systems engineer who'd be happy to help solve this with a small microcontroller with a DAC/ADC pair and some signal processing on a new bundle of wires board revision, but I'd love to work with Falcon on that rather than do my own thing.

I’ve found them to be rather receptive via eBay contact seller.

 

[cdeleo]

Just curious of any updates on this? I live in a cold area of the US and was just about to do the DIY upgrade.

 

[android04]

Just curious of any updates on this? I live in a cold area of the US and was just about to do the DIY upgrade.

No problems supercharging with my DIY upgrade. I did mine in April of 2022. Haven't had any issues in hot not cold. I live in Nebraska and we've had multiple days of very cold temps in the past few years. I've also driven down to South Texas with it and also had no issues. I would not hesitate to do this upgrade again.