PCM Replacement in 25 4S

[ze_shark]

So that's already 5 forum users reporting PCM/Porsche Connect related issues on J1.2:

joefig44
someTimesJoe
ntacus
Speuk
FrozenBerry_4s

Concerning.

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[Speuk]

So that's already 5 forum users reporting PCM/Porsche Connect related issues on J1.2:

joefig44
someTimesJoe
ntacus
Speuk
FrozenBerry_4s

Concerning.

Yep,
I would not to in a hurry to have the new 2026 pcm. I'm assuming it will be the same as the Macan EV running on Google platform. If you look at the Macan EV forum they seem to have many issues with the software.

 

[someTimesJoe]

Was supposed to pick up my car today. They said they did all the resets and everything. I had them try logging in with any account or even a dummy account. Nope. Saved myself a trip there.
Probably won’t hear back until mid next week as they need to get with technical support.
My Macan EV 4S loaner isn’t too bad but it has quirks and bugs of its own, too that annoys me already.

 

[Speuk]

Any updates on this issue?

 

[someTimesJoe]

Any updates on this issue?

Nothing unfortunately. They’re having back and forth with technical support from Germany and that just delays things. They’re just spinning their wheels right now. More news next week if anything.

 

[chun]

It’s comical how “German engineering” is such not a thing anymore (brake failures, airbag failures, pcm failures, heater failures, and it keeps going, all things that should be tested and over tested before making it to customers)

both the new taycan and the macan ev have major PCM failures, among other major failures.

And supposedly they are bringing a newer(? Maybe the same) version of the Macan EV one to all cars from porsche MY26. So they are making plans to use a part with known wide range failures…

Has me worried about how clusterfucked their architecture is in terms of ECU communications to the PCM, if it got worse over the years and not better, and if porsche is not even considering and alternative from a software first company (say rivian)

The lack of foresight in this aspect from porsche is baffling. Millions of km tested, but in those millions they don’t actually use production PCM or software. Why? Treating the customers as a testing platform for your clusterfuck is going to ruin their reputation eventually, as it already did in China.

 

[Speuk]

Update....

Well amazingly my connection has returned! Typical as it is booked into the OPC tomorrow which I'll now cancel. The only thing which may have had a bearing on it was that the car has spent the last two days in an underground car park with zero mobile signal. I've tried the same routine most days for the last few weeks. Take the car out of privacy mode then try to log in. This time when I checked "Add an account it offered me the QR code which it hasn't done for weeks. Scanned the code and hey presto my account popped up and I then successfully stepped through the various screens and successfully logged on. App is now syncing with the car.

 

[someTimesJoe]

Update....

Well amazingly my connection has returned! Typical as it is booked into the OPC tomorrow which I'll now cancel. The only thing which may have had a bearing on it was that the car has spent the last two days in an underground car park with zero mobile signal. I've tried the same routine most days for the last few weeks. Take the car out of privacy mode then try to log in. This time when I checked "Add an account it offered me the QR code which it hasn't done for weeks. Scanned the code and hey presto my account popped up and I then successfully stepped through the various screens and successfully logged on. App is now syncing with the car.

Awesome to hear. I kept telling the dealer that if that QR code doesn’t pop up, it’s not working yet they keep trying. Login screen won’t take anything even if it’s fake.

 

[ntacus]

Your problem getting resolved after sitting unconnected offgrid for 2 days feels like something just needed to be reset. It's ridiculous that Porsche removed the PCM reset function present in older models/software versions. I've also been told by my dealership that the only way to reset now is to either disconnect the 12V battery, or let the car sit overnight. Given the flakiness of their software that's just absurd.

 

[Speuk]

Your problem getting resolved after sitting unconnected offgrid for 2 days feels like something just needed to be reset. It's ridiculous that Porsche removed the PCM reset function present in older models/software versions. I've also been told by my dealership that the only way to reset now is to either disconnect the 12V battery, or let the car sit overnight. Given the flakiness of their software that's just absurd.

Yep, I think leaving it underground at my son's apartment for the weekend broke the 4G connection which is continuous even when switched off as the App/servers need to communicate with the car. I had tried the 12V battery disconnect for just over an hour but clearly that was not long enough to drain the Conbox back up battery.

I suspect it would have been a quick fix at the dealer using PIWIS to reboot the ConBox, despite the tech saying that rarely works.

 

[Johan Meert]

I also wrote this in another thread.

New car, connection stopped after 3 months on feb 13.
It came back for 4 hours on mar 28.
It went to the shop on apr 15 where they did the WRV3 update, connection worked again for a few hours but by the time I got home after collecting the car connection was already down again.

 

[Boss Hogg]

10 months and 16k miles in my J1.2, no PCM issues, been rock solid (touching wood)

 

[joefig44]

My connection never came back on its own.
My dealer replaced a chip that came from Germany (had to wait two weeks for it to arrive).
Connection restored and no problems ever since.

 

[FrozenBerry_4s]

@joefig44 it was the same for me, they have replaced the ConBox twice already for me.
The first time it worked for about 1-1.5 months then the issue came back.. Since the second time its still working (3weeks and still going strong) so fingers crossed.

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