Fuse 8? (US Taycan)

[vmporsche]

I have been having trouble logging into Porsche Connect from the PCM for weeks now and have found several posts that say to remove fuse 8 for 15 minutes; when I look at the fuses (US Model), I don't seem to have a fuse 8 on Row A- am I looking at this wrong? Thank you.

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[buruburu]

8 isn't even the right fuse. According to the owner's manual 8 on a LHD car is "Radio-controlled parking control unit (left-hand drive), charge port sensor (right-hand drive)". You probably want either fuse 2 or 7 on the right fuse box that is to the right of the dashboard. Not the footwell.

Check your owner's manual.

 

[tbinmd]

You're better off, disconnecting the 12v battery in the trunk to reboot the whole car.

 

[tbinmd]

here's the write up on how to disconnect the battery.

https://www.taycanforum.com/forum/threads/how-to-disconnect-12v-battery.11322/

 

[W1NGE]

I have been having trouble logging into Porsche Connect from the PCM for weeks now and have found several posts that say to remove fuse 8 for 15 minutes; when I look at the fuses (US Model), I don't seem to have a fuse 8 on Row A- am I looking at this wrong? Thank you.

Rather than do this have you had your car updated either the major software release (uPdate) as discussed in detail on this forum?

If not time to do so

 

[FlyingPoint]

If you have a slanted line going through your LTE icon on the PCM and it has not self corrected in weeks, it probably means a trip to the workshop for reprogramming.

 

[W1NGE]

If you have a slanted line going through your LTE icon on the PCM and it has not self corrected in weeks, it probably means a trip to the workshop for reprogramming.

Or 12v battery disconnect.

 

[rs38]

would be really nice to have a collection of fuses to pull if some ECUs are behaving weird!

It's more convenient than unscrew the 12V battery and it's the recommended way as seen in the WNJ8/ANA6 TI PDFs before cutting full power at the 12V minus connector.


OTA control unit:
Remove fuses from the OTA control unit. Use the PIWIS Tester to check whether the OTA control unit can be reached in order to check whether the correct fuse was removed (multiple fuses installed for the OTA control unit) • Start programming again via Serv.-sales and breakdown control

in general:

• Check on whether the control unit can be accessed using the PIWIS Tester or if bus idle does not have to be carried out
• Control unit still not accessible –> Remove fuse for control unit –> Ignition on –> Ignition off –> Re-insert fuse
• Control unit still not accessible –> Disconnect battery overnight
• Check whether the control unit is accessible

 

[FlyingPoint]

Or 12v battery disconnect.

Unfortunately, that solution did not work for me.

 

[W1NGE]

Unfortunately, that solution did not work for me.

Ok sorry if I missed that.

That being the case possibly won't alter with pulling fuses.

Some owners have had their Comms module replaced several times and so it could be yours has gone faulty too unfortunately.

 

[BMonte13]

Had this issue after my internal alarm sensor was replaced. There’s a tech (Ike) at Porsche Walnut Creek CA who figured out how to reboot and restore my LTE. I’d recommend calling them and having them connect with your local Porsche service.

 

[vmporsche]

Thanks, all. I opened a case with Porsche (five weeks ago!), and they said the Over the air controller needs to be replaced... again... so tired of the bugs, recalls, and failed components. And yes, I've had all recalls/updates done

 

[whitex]

Are you guys sure that disconnecting the 12V battery also disables the DC-2-DC converter which supplies and charges the 12V battery? On Teslas I played with, disconnecting just the 12V battery when DC-2-DC is engaged will not remove the 12V supply from the car. DC-2-DC is on whenever the car is ON, which includes when your HVAC is on.

 

[whitex]

would be really nice to have a collection of fuses to pull if some ECUs are behaving weird!

It's more convenient than unscrew the 12V battery and it's the recommended way as seen in the WNJ8/ANA6 TI PDFs before cutting full power at the 12V minus connector.


OTA control unit:
Remove fuses from the OTA control unit. Use the PIWIS Tester to check whether the OTA control unit can be reached in order to check whether the correct fuse was removed (multiple fuses installed for the OTA control unit) • Start programming again via Serv.-sales and breakdown control

in general:

• Check on whether the control unit can be accessed using the PIWIS Tester or if bus idle does not have to be carried out
• Control unit still not accessible –> Remove fuse for control unit –> Ignition on –> Ignition off –> Re-insert fuse
• Control unit still not accessible –> Disconnect battery overnight
• Check whether the control unit is accessible

Just FYI, AFAIK LTE is not part of the OTA control unit, it is part of the conBox-High. OTA module gets connectivity from the conBox-High via the gateway. Side note, conBox-High has an internal backup battery so few minutes without 12V will not necessarily power cycle everything.

Below is what this battery looks like inside the conBox-High ECU. 7.04Wh capacity, but not sure (at least yet) what it backs up and for how long (could be full LTE modem, could be just modem/eSim parameters). Perhaps the step "disconnect battery overnight" is meant to ensure this battery drains completely?

PS> I wonder how often this battery needs replacing - the design looks like it's a serviceable part - takes one screw to get into the battery compartment and the battery has a connector (not soldered in). I also wonder whether it dying or not holding charge will result in LTE not working correctly.

 

[rs38]

good point!

so resetting it via OBD maybe helping way more that pulling fuses etc.

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