J1.2 PCM stuck offline — "login not possible" — anything left to try before a dealer visit?

[Taycan18]

One week into ownership of my COP J1.2 and the PCM refuses to get online properly.

Started when the My Porsche app stopped syncing after I connected the car to WiFi and set a charging schedule. Since then the PCM appears unable to authenticate — every login attempt returns "login not possible", and the car is stuck in guest profile with no way to save settings. I made the error of resetting the PCM to factory, so my old user profile is gone.

Confirmed working/checked:

• Porsche Connect subscription active
• Embedded SIM showing signal
• Porsche ID credentials fine (reset password, logged in/out of My Porsche)

Already tried:

• PCM soft reset
• 12V battery disconnect ×2
• Terminal 30 fuse + connectivity module fuses pulled
• Privacy mode toggled on/off (left it a while)

Am I right in thinking this is a backend/primary-user registration issue rather than the car itself — or is this an OCU/PCM fault needing PIWIS? Anyone been through this on a J1.2?

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[refazi]

Known issue on the j1.2, some dealers reset it and other replace the Conbox of the car, I had both down in the same car, works for few months and the problem comes again, before the last repair I returned the car since the lease term ended..

 

[Tooney]

In the corner of PCM, do you have symbol 4G (or LTE) displayed, or two parallel lines with a backslash?
The 4G/LTE symbol displayed means vehicle has cellular data connection to Porsche servers.
Otherwise no data connection.

Also: take a look at Porsche Connect status settings in PCM to check what services are listed as other than active/subscribed.

Link to most recent TSB listing troubleshooting steps by dealer: https://static.nhtsa.gov/odi/tsbs/2026/MC-11028547-0001.pdf

 

[W1NGE]

One week into ownership of my COP J1.2 and the PCM refuses to get online properly.

Started when the My Porsche app stopped syncing after I connected the car to WiFi and set a charging schedule. Since then the PCM appears unable to authenticate — every login attempt returns "login not possible", and the car is stuck in guest profile with no way to save settings. I made the error of resetting the PCM to factory, so my old user profile is gone.

Confirmed working/checked:

• Porsche Connect subscription active
• Embedded SIM showing signal
• Porsche ID credentials fine (reset password, logged in/out of My Porsche)

Already tried:

• PCM soft reset
• 12V battery disconnect ×2
• Terminal 30 fuse + connectivity module fuses pulled
• Privacy mode toggled on/off (left it a while)

Am I right in thinking this is a backend/primary-user registration issue rather than the car itself — or is this an OCU/PCM fault needing PIWIS? Anyone been through this on a J1.2?

If this is an ongoing issue can you explain why you connected the car to WiFi (I take this to mean an external hotspot / home network)?

12v battery disconnect (up to 5 mins) generally is enough time to cold start all 12v systems including the PCM.

Have you tried your secondary Porsche ID and spare key fob if the ID is associated with that fob? If not give it a try and first lock the car with the primary fob, leave for 30 mins and then unlock with the secondary.

Issue normally relates to the car and so local - screwed cached credentials, poor cell connection or faulty comms box are the usual culprits

Porsche ID / password combo on mobile device the same as attempted on the car is another verification step.

 

[whitex]

Does the PCM acquire an IP from your WiFi hotspot, and does it send/receive any traffic?

 

[Taycan18]

In the corner of PCM, do you have symbol 4G (or LTE) displayed, or two parallel lines with a backslash?
The 4G/LTE symbol displayed means vehicle has cellular data connection to Porsche servers.
Otherwise no data connection.

Also: take a look at Porsche Connect status settings in PCM to check what services are listed as other than active/subscribed.

Link to most recent TSB listing troubleshooting steps by dealer: https://static.nhtsa.gov/odi/tsbs/2026/MC-11028547-0001.pdf

Thanks, I do have a 4G symbol. Every time I start the car it asks me if I want to use online services or not. If I click yes, all the Porsche Connect status settings in PCM show as active.

If this is an ongoing issue can you explain why you connected the car to WiFi (I take this to mean an external hotspot / home network)?

12v battery disconnect (up to 5 mins) generally is enough time to cold start all 12v systems including the PCM.

Have you tried your secondary Porsche ID and spare key fob if the ID is associated with that fob? If not give it a try and first lock the car with the primary fob, leave for 30 mins and then unlock with the secondary.

Issue normally relates to the car and so local - screwed cached credentials, poor cell connection or faulty comms box are the usual culprits

Porsche ID / password combo on mobile device the same as attempted on the car is another verification step.

The issue only started after I connected to WiFi (this no longer works, option gone) and set up a charging profile. I don't know if it is connected.

Second key fob, same issue. I can't set up a user profile and am stuck in guest mode.

Does the PCM acquire an IP from your WiFi hotspot, and does it send/receive any traffic?

The option to connect to Wifi disappeared after the reset!

 

[Taycan18]

Connect services showing as active:

Only guest account (unable to add a new account, no QR code):

When trying to login, I get the following error:

4G active

Ability to connect to external WiFi is gone (previously I was able to connect to my home WiFi)

Also, all apps (Spotify, Apple Music, Youtube on the passenger display etc) are gone and the built in maps is unable to do an online search despite showing 4G (but maybe linked to not being logged into an account).

 

[whitex]

Sadly, Porsche seems rather lost in the 21st century tech. Internet and connected services are is still black magic to them, as are processes such as Continuous Integration via OTA. VWAG really should have invested in proper car connectivity for all sub-brands to share and then let the sub-brands skin any way they want to. I like VWAG, I've owned VW, Audi, and Porsche cars, but I've also owned Teslas. If Tesla was able to get connectivity right producing 2,650 Model S'es in 2012 and over a million a year today, VWAG should have been able to get it right too, or just buy it from some company who knows how to run reliable connected services (Amazon perhaps, or heck, Tesla if you want automotive track record), at least until VWAG has a competitive solution of their own. Outsourcing it to the lowest bidder who vibe codes the connected solution so it works for an executive demo is not the correct solution. At the very least they should have metrics measuring reliability (and any car which just cannot connect should ding the metric big time), then dock all executives bonuses for bad reliability (perhaps missing out on a few million bonus will set help guide their priorities?). Yea, I get it, VWAG executives are old and get chauffeured around, so they never get to try their own products, while Elon still drives Teslas and all hell breaks loose as he overreacts if the his car doesn't work right, but still, capture reliability in some meaningful metrics and make those metrics count! Or maybe they are collecting metrics on reliability, but they are only reported if the system is operational so it can even report the metrics, so "login not possible" never gets logged because the telemetry reporting software cannot login to report it? </rant>

 

[W1NGE]

Thanks, I do have a 4G symbol. Every time I start the car it asks me if I want to use online services or not. If I click yes, all the Porsche Connect status settings in PCM show as active.



The issue only started after I connected to WiFi (this no longer works, option gone) and set up a charging profile. I don't know if it is connected.

Second key fob, same issue. I can't set up a user profile and am stuck in guest mode.



The option to connect to Wifi disappeared after the reset!

Have you set up the secondary Porsche ID profile via the My Porsche App (don't create on PCM - only use to login when created)?

In My Porsche App launch the the web interface from 'My Profile', which takes you to a profile page, scroll left to Secondary User and create.

Cell connection looks a bit weak - when secondary is established go somewhere where you know the cell signal to be much stronger (or try where you are just in case) and see what difference if any.

WiFi is not needed for any charging setup or programming.

Make sure WiFi is disabled in PCM before attempting to connect again.

No need (really) to mess around with WiFi (new feature to J1.2 and only Russian destined J1.1s had this ability). It may be coincidental that this screwed things up but possible - domain resolution, certificate issue / confusion and more besides.

With a new Porsche ID created you will at least establish that it is a core connectivity issue or not.

 

[Schroederhc]

Known issue, schedule appointment at dealer. They need to do an update. I went through this last fall 2025 Taycan 4

 

[SoccerMan94043]

I had some conflicts when I first set things up staying connected to my home WiFi and Carplay. I disabled WiFi and haven't had any issues since (haven't had a need for wifi at all, though youtube will play faster).

 

[Speuk]

One week into ownership of my COP J1.2 and the PCM refuses to get online properly.

Started when the My Porsche app stopped syncing after I connected the car to WiFi and set a charging schedule. Since then the PCM appears unable to authenticate — every login attempt returns "login not possible", and the car is stuck in guest profile with no way to save settings. I made the error of resetting the PCM to factory, so my old user profile is gone.

Confirmed working/checked:

• Porsche Connect subscription active
• Embedded SIM showing signal
• Porsche ID credentials fine (reset password, logged in/out of My Porsche)

Already tried:

• PCM soft reset
• 12V battery disconnect ×2
• Terminal 30 fuse + connectivity module fuses pulled
• Privacy mode toggled on/off (left it a while)

Am I right in thinking this is a backend/primary-user registration issue rather than the car itself — or is this an OCU/PCM fault needing PIWIS? Anyone been through this on a J1.2?

I had an issue with my J1.2 4S ST a while back. 4G showing but no data being transferred to/from Porsche Servers. Porsche Connected Services advised doing the factory reset...big mistake as then like you I couldn't log back in. Booked it onto OPC who thought it might need a new Conbox. The day before my booking I happened to park on a basement car park below our son's flat. Drove out and everything sprung to life and I was able to log back in to my Porsche account.

if you have an underground car park nearby might just be worth parking up for a while with no signal. The tech at my OPC thought rebooting the mobile connection was almost certainly the fix. The car never breaks this connection as it is required even when everything is switched off. The Conbox has its own back up battery so 12v disconnect doesn't help if the problem is Conbox related.

 

[mhw23]

I literally just got my car back last week from this exact issue. Had to replace the conbox. Make sure you check that your app can connect before you leave the dealership. I had to take it back because it was working in the car, but not my app. Easy fix but still annoying in the 21st century. Came from a Tesla Model S so the tech is def. a step down. I had a Macan EV loaner and the new Android based system, which is in the 2027 Taycan is much better and faster.

 

[W1NGE]

I had an issue with my J1.2 4S ST a while back. 4G showing but no data being transferred to/from Porsche Servers. Porsche Connected Services advised doing the factory reset...big mistake as then like you I couldn't log back in. Booked it onto OPC who thought it might need a new Conbox. The day before my booking I happened to park on a basement car park below our son's flat. Drove out and everything sprung to life and I was able to log back in to my Porsche account.

if you have an underground car park nearby might just be worth parking up for a while with no signal. The tech at my OPC thought rebooting the mobile connection was almost certainly the fix. The car never breaks this connection as it is required even when everything is switched off. The Conbox has its own back up battery so 12v disconnect doesn't help if the problem is Conbox related.

Ah!

 

[Tooney]

The 4G symbol display means that your car has cellular data connection with Porsche servers.

If you have not done so, contact Porsche customer service 'Porsche mobility' about the problem. They will want you to go through various troubleshooting steps, ending with factory reset. Tell them you have done all that & need to have someone check your account configuration. Here in USA they will want photos - the ones you posted above plus photo of the PCM showing LTE/4G symbol and photo of the green LED light near the interior mirror. It will take them at least a week to respond and you may have to call back for status.

and/or
Take the car into dealer for them to do steps in TSB.
Good luck.

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