[March 2026 Update] - Porsche's ONLY OTA update hobbles North American Taycans to max 9.6 kW charge rate…

[whitex]

My J1.2 also charged at 48A/10.6KW when it was new. The major update that brought the PCM version to 4360 also reduced the maximum A/C charging speed to 40A/9.6KW. (That update was done at the dealer, not OTA).

This would suggest that the PCM has a way to control the max charge rate, which would make it an even bigger omission on Porsche's side not to include ability to control the max current in the PCM. It is a very useful feature, allowing users to limit the charging current via the PCM or the app.

I'd be fascinated if your contacts at Porsche are willing to reveal anything about this change, but I'd also be very surprised.

A lawsuit would be another way to extract an explicit response.

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[SergeyIndy]

So have we concluded if it is WST2 or WSS4 OTA update that allegedly limits the 11kW OBC to 9.6kW?

WST2 came in first and installed on its own when car was locked and still ok to get 11kW, but cannot confirm for sure, as it appeared and disappeared without me initiating the install. The description only mentioned 7 min install time and improved battery diagnostics, and I did not see the campaign number. It may come back, since AI tells me WST2 is related to PCM, improved connectivity, and route planning with no mention of battery diagnostics.

WSS4 came in right after and sure got me neutered to 8.9kW at car and with charger showing 9.56kW output and 39Amp. Descriptions showed that "This update resolves an issue that may intermittently prevent charging at AC pedestals and prepares your vehicle for Plug & Charge capability at a select charging network." Maybe they are talking about Tesla, so will try that again and see if that is true.

@Techwizard100 is the lucky one but since his is a 2024 it may not be impacted

Mystery solved.

This is what AI tells me what this did, so basically charging reliability improved:

 

[whitex]

WSS4 came in right after and sure got me neutered to 8.9kW at car and with charger showing 9.56kW output and 39Amp. Descriptions showed that "This update resolves an issue that may intermittently prevent charging at AC pedestals and prepares your vehicle for Plug & Charge capability at a select charging network." Maybe they are talking about Tesla, so will try that again and see if that is true.

It seems you've identified the culprit OTA update - WSS4.

Note how Porsche skillfully hid the nerfing limitation under the "This update resolves an issue that may intermittently prevent charging at AC pedestals". Sure, there are crappy, or badly installed EVSEs out there, or garages which get too hot for >40A charging. I personally came across a situation on a trip recently, where my Taycan would start a session at 15kW (I presume 72A at 208V), in the car showing 13.6kW, but charging would terminate out within 10 minutes requiring an EVSE reset. I watched a Kia and a Tesla charge at that charger without issue, so presumably they were limited to 32A/40A/48A, or maybe they just discovered what I discovered but in their cars they could limit the charging speed to even lower current to keep it from erroring out. My Taycan charges at home at 19.2kw (80A/240V) with no problems, on a Tesla EVSE, so my OBC was not the reason for the error. So yes, having my OBC limited to 40A probably would have resolved this particular problem, but that would be "pouring the baby out with the bath water". The proper solution to resolve such issues is to allow the driver to limit the max current the car draws from the EVSE via the PCM and MyPorsche app, just like Tesla and other EVs have been doing for over a decade (yes, since before MissionE was even a dream, so no excuse for Porsche about not knowing about such a feature).

 

[SergeyIndy]

^ well said @whitex that is exactly what I do most of the time is set my EVSE to lower if I do not need to charge at the max 48Amp. However, if I do need a quick fast charge then I set it to 48Amp. Well now, no point as 39Amp that I am getting is about as low as I would be going. I do not think reporting this to corporate or dealer will help, but I will still make a call. Now this is as bad as Macan EV that is limited to that from factory in the US.

 

[Voltaire]

This would suggest that the PCM has a way to control the max charge rate, which would make it an even bigger omission on Porsche's side not to include ability to control the max current in the PCM. It is a very useful feature, allowing users to limit the charging current via the PCM or the app.

I did not mean to imply that it was the update of the PCM itself to version 4360 that reduced the charging speed. It's a convenient shorthand I was using to describe a larger update, since the PCM version is one of the few version numbers we have access to.

But in fact the big update I mentioned was campaign ARB8. There are up to 25 modules updated as part of this campaign, including the OBC itself (which answers my question from earlier about whether the OBC has internal software or is controlled by another module.) This update was done on my car around Dec 20 2024, and after that date I never again saw AC charging speeds above 9.6 KW. The patch notes in that bulletin just say this for the update to the OBC:

> Various increases in robustness, avoidance of possible fault displays on the instrument cluster

Worth mentioning, perhaps: this campaign did in fact fix a lot of minor bugs in the car, most of which I can't remember anymore. It was also the update that removed the two-finger reset from the PCM.

Has the J1.1 gotten these same updates to its various modules through other campaigns? It certainly seems to be getting the same OBC update in some but maybe not all cases.

 

[berenger24]

I am trying to follow this, I have the notificaiton for WSS4 too but can we confirm this is impacting cars outside of North America? I am Australia based not sure if there are fellow Aussies here who have done it..

 

[whitex]

^ well said @whitex that is exactly what I do most of the time is set my EVSE to lower if I do not need to charge at the max 48Amp. However, if I do need a quick fast charge then I set it to 48Amp. Well now, no point as 39Amp that I am getting is about as low as I would be going. I do not think reporting this to corporate or dealer will help, but I will still make a call. Now this is as bad as Macan EV that is limited to that from factory in the US.

When Tesla secretly disabled air suspension back in 2013, even their service centers were kept in the dark - Elon really didn't want people declining OTAs. A number of people, myself included, went into service to try to fix it, stumping the service department. Only after most cars accepted the update, did Elon finally admit it to. I was sad to find out that my sarcastic speculation that it was Elon placating the media, turned out to be true.

So it very well may be that Porsche hasn't informed the dealers about the underhanded nerfing of Taycan OBC performance in WSS4.

 

[SergeyIndy]

@whitex my dealer always tells me the usual rehearsed response, we are the last to know. One thing comes to mind is Apple when they slowed the phones with an update forcing people to upgrade to new ones. This update did not disclose in description or letter the reduction of essential function. I will let you know what response I get from dealer and corporate.

 

[chun]

Has the J1.1 gotten these same updates to its various modules through other campaigns? It certainly seems to be getting the same OBC update in some but maybe not all cases.

No.

I did after pressurig my service, following several months of issues. But there is no camapign from porsche to update all ECUs on j1.1

 

[RED!]

I am trying to follow this, I have the notificaiton for WSS4 too but can we confirm this is impacting cars outside of North America? I am Australia based not sure if there are fellow Aussies here who have done it..

I’d go with the plan: if it ain’t broke don’t fix it. Since fixing it may be the same as nerfing it.

 

[SergeyIndy]

I am trying to follow this, I have the notificaiton for WSS4 too but can we confirm this is impacting cars outside of North America? I am Australia based not sure if there are fellow Aussies here who have done it..

I would like to ask you to apply the update and let us know if your AC speed is reduced from 11kW to 9kW. This update supposed to fix AC charging issues (I never had any), but it reduces charging speed, so it broke my charging speed.

I did call corporate and they told me that there is nothing they can do as they have no way to escalate this to anyone for an explanation.

 

[gnr3312]

So in reviewing the update documentation it says it is to prepare my vehicle for Plug & Charge capability at a select network. Could it be Tesla?

 

[SergeyIndy]

So in reviewing the update documentation it says it is to prepare my vehicle for Plug & Charge capability at a select network. Could it be Tesla?

My thought exactly. I will be testing it again as none of Tesla chargers I tried activate via Plug & Charge.

 

[RED!]

I would like to ask you to apply the update and let us know if your AC speed is reduced from 11kW to 9kW. This update supposed to fix AC charging issues (I never had any), but it reduces charging speed, so it broke my charging speed.

I did call corporate and they told me that there is nothing they can do as they have no way to escalate this to anyone for an explanation.

I don’t think it’s a great idea to “experiment” with something that will permanently nerf your car when we’re all quite sure it will. Kinda like asking the dude to try some minor brain surgery becuase it just might not make him dumber…

My advice: skip it for as long as you can, wait until someone here raves about some awesome new feature that was unlocked. Personally, all I got for my willingness to stay up to date was slower charging.

 

[SergeyIndy]

I don’t think it’s a great idea to “experiment” with something that will permanently nerf your car when we’re all quite sure it will. Kinda like asking the dude to try some minor brain surgery becuase it just might not make him dumber…

My advice: skip it for as long as you can, wait until someone here raves about some awesome new feature that was unlocked. Personally, all I got for my willingness to stay up to date was slower charging.

My only word of caution is that these updates are related to safety, so if something happens and you are found ignoring it, then there are bigger problems to be had. I am not sure if I reported already but corporate customer service was not helpful and could not even take it down as a concern with my ask to review and respond.

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