Service

Technical Information

92/25

ENU

9125

Various Complaints in Connection with the External Communication Control Unit/ No Stored Fault
Memory Entries (92/25)

9

Model Line:

Taycan (Y1A/Y1B/Y1C)

Model Year:

As of 2020

Concerns:

External communication control unit (Connect control unit)

Information:

The customer has various complaints in connection with the external communication control unit, such as
restrictions on Connect services.
No fault memory entry is stored in the fault memory of the external communication control unit:

Action:

If there is a customer complaint, reset and start the external communication control unit.
Information
The test steps listed in this measure describe the correct procedure for performing a reset of the external
communication control unit and must be carried out one after the other.
After each successfully performed test step, the customer complaint must be checked again.

Information
The action described in this Technical Information is only valid if no fault memory entries are stored in the
external communication control unit.

Required tools
Tool:

•
•

P90999 - Porsche Tester 4
Battery charger with a current rating of at least 90 A and a current and voltage-controlled charge map
for lithium starter batteries, e.g., VAS 5908 - battery charger 90 A. For further information about the
battery chargers to be used, see the corresponding Workshop Manual. ⇒ Workshop Manual '270689
Charge battery and vehicle electrical system'

Resetting and starting external communication control unit
Information
In the event of faults or functional restrictions, log in using the Porsche ID and using the security code in the
PCM.
Work Procedure: 1

Connect and switch on the battery charger.

⇒ Workshop Manual '270689 Charging the battery/vehicle electrical system'

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2

Place the original remote control in the emergency start tray.

3

Connect P90999 - Porsche Tester 4, establish readiness for operation and start the diagnostic application.

4

Perform the integration test using the automated procedure with Porsche Tester.

5

4.1

Start the integration test with Porsche Tester.

4.2

Check Connect control unit for mandatory updates and run any that are available.

4.3

Check the Gateway control unit, Connect control unit and Over-the-Air (OTA) control unit for
optional updates and run any that are available.

Check and evaluate the customer complaint again.
Assessment
( )

Customer complaint no longer exists.

Action
End of action.
•
•

✗)
(✗

Customer complaint still exists.

End the diagnostic application, end readiness
for operation and disconnect P90999 Porsche Tester 4 from the vehicle.
Switch off and disconnect the battery
charger.

Continue with Step ⇒ 6.

or
No updates available.
6

7

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Deactivate flight mode.
6.1

In the Overview, select the "Connect" control unit. Press •F12“ to continue.
Should a Vehicle Analysis Log (VAL) be created? Press •F11“ to continue.

6.2

Select “Service/repairs”.

6.3

Select “Deactivate flight mode”. Press •F12“ to continue.
6.3.1

Read and follow the instructions and information on the Tester.

6.3.2

Deactivate flight mode according to menu guidance.

6.4

Return to the “Overview” of all control units.

6.5

In the “Overview”, press •F7“ to switch to the “Additional menu”.

6.6

Read out all fault memories; process and delete existing faults if necessary.

Check and evaluate the customer complaint again.

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Technical Information

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Assessment

( )

Customer complaint no longer exists.

8

9

9

End of action.

•
Customer complaint still exists.

9125

Action
•

✗)
(✗

ENU

End the diagnostic application, end readiness
for operation and disconnect P90999 Porsche Tester 4 from the vehicle.
Switch off and disconnect the battery
charger.

Continue with Step ⇒ 8.

Carry out a soft reset of the external communication control unit.
8.1

Select the Connect control unit in the “Overview”) menu), and confirm with •F12“ (“Next”).

8.2

In the “Control links check” menu, select “Control links”, and confirm with •F12“ (“Next”).

8.3

Select the “Control unit, unexpected reset” function and press •F12“ (“Next”) to confirm.

8.4

Start the routine by pushing •F8“ (‘Start’) and follow as per menu.

8.5

The Connect control unit is fully reset.

Check and evaluate the customer complaint again.
Assessment
( )

Customer complaint no longer exists.

Action
End of action.
•
•

✗)
(✗

Customer complaint still exists.

End the diagnostic application, end readiness
for operation and disconnect P90999 Porsche Tester 4 from the vehicle.
Switch off and disconnect the battery
charger.

Continue with Step ⇒ 10.

10 Carry out a hard reset on the external communication control unit.
Information
For vehicles with active VTS (Vehicle Tracking System)
Before removing the external communication control unit, it must be ensured that VTS workshop mode
is activated.
10.1

Remove the external communication control unit.
⇒ Workshop Manual '912519A3 Removing and installing external communication control unit'

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10.2

Remove the internal battery of the external communication control unit and leave it separate
from the external communication control unit for at least 15 minutes.
⇒ Workshop Manual '912519A1 Removing and installing battery for external communication
control unit'

10.3

After waiting, install the internal battery of the external communication control unit.
⇒ Workshop Manual '912519A1 Removing and installing battery for external communication
control unit'

10.4

Install and re-teach the external communication control unit.
⇒ Workshop Manual '912519A3 Removing and installing external communication control unit'
and
⇒ Workshop Manual '912555A3 Replacing external communication control unit'

Check and evaluate the customer complaint again.
Assessment
( )

Customer complaint no longer exists.

Action
End of action.
•
•

✗)
(✗

Customer complaint still exists.

End the diagnostic application, end readiness
for operation and disconnect P90999 Porsche Tester 4 from the vehicle.
Switch off and disconnect the battery
charger.

Continue with Step ⇒ 12.

12 Carry out a hard reset on the over-the-air (OTA) control unit.

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12.1

Remove the over-the-air (OTA) control unit and leave it separate from the vehicle for at least 15
minutes.
⇒ Workshop Manual '919819A1 Removing and installing over-the-air control unit'

12.2

After waiting, install the over-the-air (OTA) control unit.
⇒ Workshop Manual '919819A1 Removing and installing over-the-air control unit'

12.3

Re-teach the Over-the-Air (OTA) control unit
⇒ Workshop Manual '919855 Replacing over-the-air control unit'

Check and evaluate the customer complaint again.

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Technical Information

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Assessment

( )

9125

9

Action

Customer complaint no longer exists.

End of action.
•
•

✗)
(✗

ENU

Customer complaint still exists.

End the diagnostic application, end readiness
for operation and disconnect P90999 Porsche Tester 4 from the vehicle.
Switch off and disconnect the battery
charger.

The customer complaint can be triggered by the
external communication control unit.
Replace the external communication control unit.
⇒ Workshop Manual '912555A3 Replacing
external communication control unit'

Labor position and PCSS encryption
Labor position:
APOS

Labor operation

I No.

91252535

Performing integration test

91252536

Performing vehicle handover (diagnostics system)

91252537

Carry out a soft reset of the external communication control unit.

91252538

Carrying out hard reset on external communication
control unit

91252539

Carrying out hard reset on over-the-air (OTA)
control unit

91255500

Replacing external communication control unit
PCSS encryption

Location (FES5)

91250

External communication control unit

Damage type (SA4)

4092

Vehicle not accessible

Important Notice: Technical Bulletins issued by Porsche Cars North America, Inc. are intended only for use by professional automotive technicians who have attended Porsche service training courses. They are
written to inform those technicians of conditions that may occur on some Porsche vehicles, or to provide information that could assist in the proper servicing of a vehicle. Porsche special tools may be necessary in
order to perform certain operations identified in these bulletins. Use of tools and procedures other than those Porsche recommends in these bulletins may be detrimental to the safe operation of your vehicle, and
may endanger the people working on it. Properly trained Porsche technicians have the equipment, tools, safety instructions, and know-how to do the job properly and safely. Part numbers listed in these bulletins
are for reference only. The work procedures updated electronically in the Porsche PIWIS diagnostic and testing device take precedence and, in the event of a discrepancy, the work procedures in the PIWIS Tester
are the ones that must be followed.

© 2026 Porsche Cars North America, Inc.

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