⚡️ Home Charging Issues after Software Update? (Tracking Thread)

[annwills]

Reviewing the data was extremely helpful for myself and my situation. Understand it may not be everyone's, but my home issues charging are clearly tied to voltage. What's interesting is I am able to watch where its trying to connect and getting the charging stopped issue, I can see what the exact voltage is the seconds before it occurs.

Then I was able to go back and see where successful and I am drawing full power on the charger, what was the voltage prior to initiating a successful charge.

I wish I was able to pull the voltage information through CSV instead of just the draws, but I sampled around 15 successful and unsuccessful charges and that's what the information shows as I can determine voltages via the app. It's cumbersome so I am going to reach out to Emporia to grab this information and hopefully at some point someone from Porsche will contact myself and I will share the information.

Two weeks ago, I contacted Porsche NA (for the 4th time) and gave a different person a detailed description of our common problem and all the steps I and my dealer tried that do not solve the problem. I followed up with an email and how the problem pointed to either new and inappropriate software sensitivity to normal electrical supply variances or to dealer error in installing the software. This time I was promised that it would be elevated to Engineering and I could expect a response in 2 weeks. So, this morning I called and left a message asking for an update. As per the previous 3 times I did not receive a response. However, late today I got a call from my dealer saying he just received a notice from Porsche that there was a new software update to be installed in cases like this. I have an appointment for next Thursday (19th) and will report back on how it went.

Regardless of how this turns out, perhaps an equally frustrating problem is how Porsche NA responds to issues like this. @toontoon 's dealer is told they are working on the problem the same day my dealer is told there is a software update. As far as I can tell, no one on this forum has been told directly by Porsche NA that they are aware of the problem or ever heard of the problem. A little transparency on Porsche's part toward their customers would go a long way.

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[Bauer83]

Two weeks ago, I contacted Porsche NA (for the 4th time) and gave a different person a detailed description of our common problem and all the steps I and my dealer tried that do not solve the problem. I followed up with an email and how the problem pointed to either new and inappropriate software sensitivity to normal electrical supply variances or to dealer error in installing the software. This time I was promised that it would be elevated to Engineering and I could expect a response in 2 weeks. So, this morning I called and left a message asking for an update. As per the previous 3 times I did not receive a response. However, late today I got a call from my dealer saying he just received a notice from Porsche that there was a new software update to be installed in cases like this. I have an appointment for next Thursday (19th) and will report back on how it went.

Regardless of how this turns out, perhaps an equally frustrating problem is how Porsche NA responds to issues like this. @toontoon 's dealer is told they are working on the problem the same day my dealer is told there is a software update. As far as I can tell, no one on this forum has been told directly by Porsche NA that they are aware of the problem or ever heard of the problem. A little transparency on Porsche's part toward their customers would go a long way.

I am hoping after the work on your car next week, assuming and hoping of course it works, is if you can share the service records. I was told today by my dealer that they are unaware of anyone else having this problem and there is nothing posted by Porsche yet for any issues related to home charging. Assuming they don’t share with you a name/contact from Porsche NA?

 

[toontoon]

I am hoping after the work on your car next week, assuming and hoping of course it works, is if you can share the service records. I was told today by my dealer that they are unaware of anyone else having this problem and there is nothing posted by Porsche yet for any issues related to home charging. Assuming they don’t share with you a name/contact from Porsche NA?

Very surprising, my dealer was able to share the minutes of the meeting. I didn't take any pictures of that but they had a meeting with Porsche NA folks who were able to confirm that Porsche Engineers are on it.

 

[Dandar245]

I just called Porsche NA again, it appears they do have a fix now. It didn't seem like it was something relayed to the dealerships as they had to contact my service center with the details for the fix. I would try calling soon and setting up that appointment. Fingers crossed

 

[Bauer83]

I just called Porsche NA again, it appears they do have a fix now. It didn't seem like it was something relayed to the dealerships as they had to contact my service center with the details for the fix. I would try calling soon and setting up that appointment. Fingers crossed

Hey,

Assuming you just called the hotline? I will do that later today.

 

[dgkhn]

FWIW, I went to my buddy ChatGPT:

Below is a version formatted for direct posting. It includes both the question and the ChatGPT response, written in neutral technical language and suitable for forum discussion.

Question (for forum discussion)
Several owners have reported that after the recent dealer-applied software update, their Porsche Macan EV fails to begin charging at home, while the same EVSE previously worked without issue. Some recent posts suggest a possible pattern: charging handshake fails when supply voltage is relatively high (around ~250 V or above), but succeeds at lower measured voltages.

Given how Level 2 AC charging works — specifically how EVSEs advertise maximum available current to the vehicle via the J1772 control pilot signal — is it technically plausible that a software update could introduce a voltage-related handshake restriction?

More specifically:

• Do EVSEs “advertise voltage” during handshake, or only maximum current?
• Would there be any engineering reason for Porsche to restrict handshake or charging initiation above a certain measured line voltage (e.g., ~250 V)?
• Could such a restriction be introduced purely in software, without hardware changes?

Response (Generated by ChatGPT)
1. How AC Level 2 Handshake Actually Works
In North America, Level 2 AC charging (SAE J1772 / CCS Type 1) works as follows:

• The EVSE does not regulate voltage.
• The EVSE provides nominal 240 V AC from the grid.
• The EVSE advertises maximum available current, not voltage.
• This is done via a PWM (pulse-width-modulated) control pilot signal.

The duty cycle of the pilot signal encodes the maximum current the EV is permitted to draw (e.g., 32 A, 40 A, 48 A). The vehicle’s onboard charger then decides how much current to draw, up to that limit.

Important:
There is no standard mechanism in J1772 by which the EVSE “advertises voltage.” Voltage is simply whatever the utility is supplying at the time.

Relevant standards:

• SAE J1772 (control pilot signaling)
• IEC 61851 (conductive charging systems)

2. What Voltage Range Is Normally Expected?
In the U.S.:

• Nominal Level 2 voltage = 240 V
• Utility tolerance is typically ±5–10%
• That means real-world voltage may range from ~228 V to ~252 V
• In some locations, brief readings above 250 V can occur

Most EVSEs and onboard chargers are designed with tolerance above nominal 240 V. A hard cutoff exactly at 250 V is not required by the charging standards.

3. Could Software Reject Charging Based on Voltage?
Yes — technically, it could.

While the EVSE does not advertise voltage, the vehicle’s onboard charger measures incoming AC voltage directly. Firmware can enforce limits such as:

• Overvoltage protection threshold
• Undervoltage protection threshold
• Signal quality validation thresholds
• Control pilot waveform tolerance validation

If a software update:

• Tightened acceptable voltage range,
• Changed filtering or noise rejection logic,
• Adjusted timing tolerances,
• Or modified pilot signal interpretation,

then charging could fail during the handshake stage even if the EVSE previously worked.

This would be entirely possible without any hardware changes.

4. Would Engineers Have a Reason to Introduce Such a Limit?
Potential reasons (hypothetical but technically plausible):

1. Safety margin adjustments
   To reduce stress on onboard charger components under high-voltage conditions.
2. Global harmonization of firmware
   A single firmware image deployed across markets (EU, US, etc.) might standardize voltage validation thresholds.
3. Noise susceptibility mitigation
   Higher line voltage sometimes correlates with waveform distortion or harmonic noise. Firmware could have been adjusted to be more strict about pilot signal validation.
4. Compliance refinement
   Updates sometimes tighten validation logic to better align with interpretation of IEC 61851 or ISO 15118 timing/validation rules.

However, there is no public documentation indicating Porsche implemented a 250 V cutoff. The standards do not mandate such a threshold.

5. Is the “~250 V Handshake Limit” Hypothesis Plausible?
Technically: Yes, plausible.

Confirmed by standards: No — not required.

Evidence in forum reports:

• Charging fails post-update.
• Some vehicles charge at dealer facilities but not at home.
• Some users report correlation with higher measured home voltage.

That pattern is consistent with:

• Firmware threshold changes
• Tighter validation logic
• Or altered pilot signal interpretation

But without Porsche diagnostic data, this remains a hypothesis.

6. Key Technical Point
The EVSE advertises maximum current only.
Voltage is not negotiated — it is measured by the vehicle.

Therefore:

If handshake failure correlates with ~250 V supply, the cause would almost certainly be vehicle-side software logic, not EVSE signaling.

If owners are able to measure and log:

• Line voltage at time of failure,
• Voltage at time of successful charge,
• EVSE model,
• Software version before and after update,

a clearer pattern may emerge.

(Response generated by ChatGPT for technical discussion purposes.)

 

[nick729]

I would not be so sure about a fix, but fingers crossed.

Porsche HQ are sending a team of 4 engineers with all the possible equipment to my home to try and figure out what the issue is. Doubt they would bother arranging flights if there was a working fix already.

They are due to come after the 23rd - date to be confirmed.

By the way, not sure if EU and US cars have different standarts for charging or if they use the same, but keep in mind that they are different from grid perspective.

Europe: 230 V per phase IEC
USA: 240 V line-to-lineNEC / ANSI

Real-world voltage ranges:
Europe: ~207–253 V (±10%)
USA (240 V): ~228–252 V (±5%)

 

[toontoon]

Hey,

Assuming you just called the hotline? I will do that later today.

I just called the hotline and they didn't seem to have any update on this specific issue. I'll call my dealership later to confirm. They speak to the HQ once a week so I doubt anything has changed since I last spoke to them (past Wednesday- 2/11).

 

[Dandar245]

I just called the hotline and they didn't seem to have any update on this specific issue. I'll call my dealership later to confirm. They speak to the HQ once a week so I doubt anything has changed since I last spoke to them (past Wednesday- 2/11).

I don’t understand why we’re all getting such different responses from them. In the mean time, I have a viable workarounds (albeit a pain in the ass). I recently bought a voltage regulator from Vevor. (65 bucks) For a regular 120 outlet you basically plug this in and can control the voltage output. I plug in the Porsche adapter slow charger and as it starts initializing, I dip the voltage to like 110. I’ve tried multiple times and have consistently got it start charging. Once the slow charge starts, the regular level two wall charger seems to get past the initialization. If you are desperate like me, you can maybe try this.

 

[daveo4EV]

Two weeks ago, I contacted Porsche NA (for the 4th time) and gave a different person a detailed description of our common problem and all the steps I and my dealer tried that do not solve the problem. I followed up with an email and how the problem pointed to either new and inappropriate software sensitivity to normal electrical supply variances or to dealer error in installing the software. This time I was promised that it would be elevated to Engineering and I could expect a response in 2 weeks. So, this morning I called and left a message asking for an update. As per the previous 3 times I did not receive a response. However, late today I got a call from my dealer saying he just received a notice from Porsche that there was a new software update to be installed in cases like this. I have an appointment for next Thursday (19th) and will report back on how it went.

Regardless of how this turns out, perhaps an equally frustrating problem is how Porsche NA responds to issues like this. @toontoon 's dealer is told they are working on the problem the same day my dealer is told there is a software update. As far as I can tell, no one on this forum has been told directly by Porsche NA that they are aware of the problem or ever heard of the problem. A little transparency on Porsche's part toward their customers would go a long way.

historically Porsche lacks transparency on engineering problems - this is not a new thing with them - and dates back to at least the IMF bearing problem with boxster engines and long time Porsche owners will tell you the same.

they are a proud german company that does not take "feedbacK" very well and they are resistant to change…

to expect them to change this decades long behavior is simply not realistic and should not be expected.

the _BEST_ you can hope from from Porsche is an actual fix, but there will never be any "tranparency" - it's simply not part their DNA or culture.

simply put this is not a new thing for them and is their standard-operating-procedure and has been for decades.

 

[Bauer83]

I don’t understand why we’re all getting such different responses from them. In the mean time, I have a viable workarounds (albeit a pain in the ass). I recently bought a voltage regulator from Vevor. (65 bucks) For a regular 120 outlet you basically plug this in and can control the voltage output. I plug in the Porsche adapter slow charger and as it starts initializing, I dip the voltage to like 110. I’ve tried multiple times and have consistently got it start charging. Once the slow charge starts, the regular level two wall charger seems to get past the initialization. If you are desperate like me, you can maybe try this.

Are you using one side of your car hooked up
to the 110V and then connect the L2 while it’s charging and it switches over?

 

[Dandar245]

Are you using one side of your car hooked up
to the 110V and then connect the L2 while it’s charging and it switches over?

No, I get the lvl 1 working first, disconnect and then hook up the lvl 2 on the same port. I don’t quite understand it myself… but it almost seems like the first initialization stays good for a while??

 

[ColdCase]

Europe: 230 V per phase IEC
USA: 240 V line-to-lineNEC / ANSI

Real-world voltage ranges:
Europe: ~207–253 V (±10%)
USA (240 V): ~228–252 V (±5%)

Just to be more complete:

So called 240 V Real world USA has a lower limit slightly below 220 V. Much of the population actually gets 110V per leg nominal, 220 line to line. Where others here report about 9.5 kW charging rate, I get 9.1 kW due to the lower voltage.

Isn't there also a frequency difference too, EU 50Hz. UA 60Hz?

Notice that the ChatGPT word soup provides wrong, misleading, or incomplete answers here, you just can't trust it for technical discussion suitable for any format until the errors are corrected.

In addition to the EVSE charging standards, EVSEs must meet safety criteria and the EVSEs I'm familiar with will cut power to the car when they sense line over and under voltage and over current. They also failsafe off for internal faults.

 

[jergans]

I received the software update in early January and had no issues charging until this week. Took my car into Greenwich, CT for service today.

They and Porsche NA are aware of the issue and have no fix at this time. As others have said, it seems that the software update narrowed the window of acceptable voltage AND it seems that some utilities in the north (of the US and world perhaps) have increased the voltage recently. Otherwise…why was I able to charge with no problem from early January until this week?

 

[SandyHaus]

Have the same new issue after charging without problem on my 12 year old Tesla 220v charger in my garage over the past 9 months. Did get the update several months ago and this only happened over the past two days (leaving the car off overnight didn’t help). Today I tried to charge using the Porsche charger that came with the car on a 115 volt outlet. Still wouldn’t work and gave the same errors. 350kW Electrify America DC charger works fine.

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