Service

Technical Information

20/26 ENU

5789

5

Replacement Requirement for Rear-End Electronics Control Unit (BCM2) (20/26)
Model Line:

911 (992)

Model Year:

As of 2020 up to 2025

Concerns:

Replacement requirement for rear-end electronics control unit (BCM2)

Information:

There are different software releases for the rear-end electronics control unit (BCM2). In principle, all
software releases are compatible with the respective affected vehicle.
However, if a replacement is necessary, there is a possibility that coding of the Gateway control unit is
required after replacing the rear-end electronics control unit (BCM2).
Otherwise, it is possible that the user login and change of user is no longer possible in the front display and
operator control panel after replacing the rear-end electronics control unit (BCM2).
The front display and operator control panel displays the Loading Spinner and then a cancellation message.
No fault memory entry is stored in the fault memory of the rear-end electronics control unit (BCM2).

Action:

If the rear-end electronics control unit (BCM2) needs to be replaced, check the software release of the
previous rear-end electronics control unit (BCM2), compare it with the new rear-end electronics control unit
(BCM2) and re-code the Gateway control unit with the Porsche Tester, if necessary, depending on the test
result.
Information
The minimum requirement for coding is the Porsche Tester software release 43.900.025 (or higher).

Information
The software release of the rear-end electronics control unit (BCM2) can be checked in the vehicle analysis
log (VAL) or read off the housing of the control unit.

Required tools
Tools:

•
•

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'

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Mar 24, 2026
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5

Service
5789

ENU

Technical Information

20/26

Checking the software release of the rear-end electronics control unit (BCM2)
Work Procedure: 1

Using a previously created vehicle analysis log (VAL) or the imprint on the previous rear-end electronics
control unit (BCM2), check the software release of the control unit.
Assessment

Action

The software release is “0604” (or higher).

No rework required.
Install a new rear-end electronics control unit (BCM2).
End of action.

The software release is lower than “0604”.
2

Continue with Step ⇒ 2.

Using the imprint on the new rear-end electronics control unit (BCM2), check the software version of
the control unit.
Assessment

Action

The software release is lower than “0604”.

No rework required.
Install a new rear-end electronics control unit (BCM2).
End of action.

The software release is “0604” (or higher).

Installing a new rear-end electronics control unit
(BCM2)
and then
Re-code the Gateway control unit.
Continue with:

⇒ Technical Information '270689 Re-coding the
Gateway control unit'

Re-coding the Gateway control unit
Work Procedure: 1

Re-code the Gateway control unit.
The basic procedure to follow for control unit coding is described in the Workshop Manual.

⇒ Workshop Manual '270689 Basic instructions and procedure for control unit programming using the

PIWIS Tester'

Specific information on control unit coding within the scope of this action:
Required Porsche Tester software release:

43.900.025 (or higher)

Type of control unit coding:

Control unit coding using the 'A utomatic coding'
function for the control unit:
Select ‘Gateway’ control unit – ‘Coding /
programming’ menu – ‘Automatic coding’ function.

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AfterSales

Service

Technical Information

20/26 ENU

Coding sequence:

5789

5

Read and follow the information and instructions on
the Porsche Tester during the guided procedure.
Do not interrupt the coding process.
When coding is complete, the message “Coding has
been completed successfully” is displayed and a tick
appears in the 'Status' box.

Procedure if control unit coding is not
successful:

Repeat control unit coding.

2

Read out and delete all control unit fault memories.

3

Exit the diagnostic application, switch off the ignition and disconnect P90999 - Porsche Tester 4 from
the vehicle.

4

Switch off and disconnect the battery charger.

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

Labor position and PCSS encryption
Labor position:
APOS

Labor operation

I No.

90352542

Programming (re-coding) the Gateway control unit
PCSS encryption:

Location (FES5)

57890

Rear-end electronics control unit

Damage type (SA4)

1143

Not working after software update

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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Mar 24, 2026
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