Taycan 12V drain issues - caught in the act?

[chrisk]

I have further proof of the fact that the car's charging fails and starts.
While reviewing PMCC Web logs I noticed that most charging sessions were not continuous. Most times charging stopped and restarted after 1-2 mins.
Attached is screenshot of logs for two sessions showing that each session stopped and restarted.

The same thing happened on a commercial ChargePoint. I received an a notification from Chargepoint app that my car was unplugged, but my car was still plugged in. I was right there looking at the car. The car just stopped charging on its own. Unlike home, in this case the car could not restart charging because that requires ChargePoint re-authorization.

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[Scandinavian]

I have further proof of the fact that the car's charging fails and starts.
While reviewing PMCC Web logs I noticed that most charging sessions were not continuous. Most times charging stopped and restarted after 1-2 mins.
Attached is screenshot of logs for two sessions showing that each session stopped and restarted.

The same thing happened on a commercial ChargePoint. I received an a notification from Chargepoint app that my car was unplugged, but my car was still plugged in. I was right there looking at the car. The car just stopped charging on its own. Unlike home, in this case the car could not restart charging because that requires ChargePoint re-authorization.

The charging process in the Taycan can be followed at the MyPorsche site if you log in. Check the home charging part and you will see how a PMCC stops and starts if you have it connected to the internet.

Below is a charge session with preheat I did today. I was surprised to see how the charger behaved. I have seen the first part before where the charger seems to check the charge ever so often. The charger is set for full power so 11 kW. Why it suddenly dropped to half the value, I have no idea. And then it switched of and restarted at a very low value after 13.00 hours? Again no idea why. I have no Connect functions any longer and nobody was close to the car or changed anything on the PMCC.

If anyone has any idea let me know please.

 

[NC_Taycan]

I have a theory that these 1-2 minute stop and starts are the HV battery topping off the 12V battery. As for why it would re-start at a lower draw, I have no idea... lower draw for pre-conditioning instead of charging might make sense but I don't think the car can request a specific charging current from the PMCC unless there is a Home Energy Manager available AND the PMCC has been configured to use it. That's just a wild guess - US doesn't have access to HEM.

 

[bushmg]

I had my 4S die while connected to the PMCC at home earlier this month. I had a Timer and a Home Profile set to charge to 85% by 7:00 AM. I drove it around normally Wednesday, put it in the garage and plugged it in as usual. Thursday morning it was dead. I called my local Porsche dealer and the Shop Foreman and Service Manager came out to the house with a battery box. However, when they connected it, the car didn't come back to life. It reported an electrical fault, and would only go into neutral. With the car in neutral, we pushed it out of the garage, and called Porsche Roadside assistance, who came out on Friday afternoon. The tow truck had a nearly discharged battery box from an earlier tow, and none of my chargers had enough power to activate the car, so we were stuck! I finally got another vehicle alongside the Taycan and jumped the battery from it. This allowed it to go into neutral and be winched on the truck. The jumper cables were noticeably warm after doing this, so there was a lot of power being used by the Taycan.

The Taycan was in the shop 15 days, as they had to clear 248 faults. Nothing was wrong with the 12 volt battery. The word from Porsche was to disable all Timers and Profiles and the Power Line Connect (if it is used - mainly a European thing) until a software fix can be found.

I had read a lot about this problem, and since I have had my 4S since June, I was hoping it wouldn't happen to me. Oops!

 

[John89]

Can't help but think after reading this - I plug in my Panamera Hybrid and it charges, I go to the gas station and fill it with gas when its low (500+ miles of range in the summer). It's winter and the Taycan is sitting @ 50% charge.......unplugged. Seems way too complex for me.

 

[chrisk]

It seems in some cases the 12v problem causes other side effects like electric faults, or PCM not being able to communicate with Porsche servers any more (corrupted OTA module). So the recovery might not just be jump the 12v battery and everything is fine.

 

[NC_Taycan]

^ what chrisk said (happened to me).

 

[Vim Schrotnock]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10185117-0001.pdf

Fantastic read, and it sounds like exactly what happened to my car. 'Deactivating PLC line' which communicates with the PHEM is what my service tech told me he did back in October. Hopefully they'll have the software fixed by the time the PHEM is available in the US.

 

[H@wk]

Very interesting. So I guess the PLC line deactivation is not something an ordinary owner can do? At least I couldn’t find that option on the portal website.

 

[Scandinavian]

Very interesting. So I guess the PLC line deactivation is not something an ordinary owner can do? At least I couldn’t find that option on the portal website.

I think you can by logging in to the charger as Customer Service. Below is a screenshot where Icould toggle the PLC and set it as inactive.

Edited since the second picture did not load

 

[NC_Taycan]

What is the customer service username and password?

This screen clearly implies that with PLC communication to the vehicle enabled, the vehicle and charger can exchange data (something not permissible with the baseline J1772 spec, but possible with the newer protocol for plug-and-charge). Plus I wonder how many 12V battery deaths are because of PMCC being shipped from the factory with this enabled by default? Wonder if that's something a dealer is supposed to change but aren't doing so (probably because they weren't told to do so as part of delivery)...?

 

[Scandinavian]

What is the customer service username and password?

This screen clearly implies that with PLC communication to the vehicle enabled, the vehicle and charger can exchange data (something not permissible with the baseline J1772 spec, but possible with the newer protocol for plug-and-charge). Plus I wonder how many 12V battery deaths are because of PMCC being shipped from the factory with this enabled by default? Wonder if that's something a dealer is supposed to change but aren't doing so (probably because they weren't told to do so as part of delivery)...?

If you check your screen with networks etc for the PMCC, you will find the IP address. Either for WiFi or for the chargers hotspot. The password that is needed in these cases were supplied in a small envelope with the charger. There are a few passwords in there, Customer and Customer service. You will need that document in the envelope though. I dont think they have the same password for all chargers though.

Also remember that I am in Europe and have the CCS2 connector, so that might be a reason there is a PLC communication between vehicle and charger indicated. I do not know if it is active, but when I plug in there is a message that a vehicle is connected. I did get the same message when I charged the Tesla M3 and a Renault Zoe with the PMCC. And both worked just fine to charge. No problems starting or stopping at set levels.

 

[NC_Taycan]

Thanks! So I still have that envelope and logged in as customer service (using the Web Tech User password on the little paper). To my surprise, the PLC connection to vehicle was enabled - so it has been since April. Even with this enabled, when my car is plugged in it shows the connected vehicle just as "connected vehicle" - nothing vehicle-specific like VIN or model that would indicate there was any data exchanged.

I wonder if this PLC connection is how the car might tell the PMCC to wait in stand-by waiting for charging to start at a preferred charging time... Wonder if everything would still work the same if this PLC connection to the vehicle was disabled...?

Let's find out. I disabled it. The TSB says time to start charging might decrease from 45 seconds to 5 seconds...

 

[daveo4EV]

ok disabled both of the "P" options via the customer service login via the web portal on the PMCC - although both times my vehicle has died (1 death, 1 attempted murder) it was charging from a Tesla gen 2 charger.

but I do occasionally charge with the PMCC when I want to heat up my garage and now it does connect/communicate with the vehicle MUCH faster - it used to take forever to connect to the vehicle when I plugged in the J-1772 - now it's immediate.

I disabled: Powerline Communication
I disabled: PLC Connection to Vehicle

 

[Vim Schrotnock]

ok disabled both of the "P" options via the customer service login via the web portal on the PMCC - although both times my vehicle has died (1 death, 1 attempted murder) it was charging from a Tesla gen 2 charger.

but I do occasionally charge with the PMCC when I want to heat up my garage and now it does connect/communicate with the vehicle MUCH faster - it used to take forever to connect to the vehicle when I plugged in the J-1772 - now it's immediate.

I disabled: Powerline Communication
I disabled: PLC Connection to Vehicle

Yes, as I posted earlier, if you are waiting more than 10 seconds for your car to start charging, you have a problem. Once you connect the charger, it should turn green within about 5 seconds. ?

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