Service

Technical Information

2025

ENU

WSC7

WSC7 - Re-Programming High-Voltage Power Electronics and PSM Control Unit (Workshop
Campaign)
Model Line:

Cayenne E-Hybrid (9YA / 9YB)

Model Year:

As of 2019 up to 2023

Concerns:

High-voltage power electronics control unit

4

PSM (Porsche Stability Management) control unit
Cause:

There is a possibility that the software of the high-voltage power electronics and PSM (Porsche Stability
Management) control units on the affected vehicles does not meet the required specifications.
If this is the case, the yellow warning message "PSM failed" in the instrument cluster can light up and lead to
a fault memory entry (P05FF00). In the further consequence, this can be perceived by the customer subjectively as a sensory change of the brake pedal in the form of a long footbrake stroke.

Action:

Re-programming high-voltage power electronics and PSM control units with the PIWIS tester.
Information
The minimum programming requirement is the PIWIS Tester software release 43.200.041 (or higher).

Affected
Vehicles:

Only vehicles assigned to the campaign (see also PCSS Vehicle Information).

Required Tools
Tool:

•
•

P90999 - PIWIS 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
Charging vehicle electrical system battery'

Re-programming high-voltage power electronics and PSM control unit
Work Procedure: 1

Re-program control unit for high-voltage power electronics.
The basic procedure for control unit programming is described in the Workshop Manual. ⇒ Workshop
Manual '9X00IN Basic instructions and procedure for control unit programming using the PIWIS Tester'
For specific information on control unit programming during this campaign, see the table below.

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Technical Information

2025

Required PIWIS Tester software release:

43.200.041 (or higher)

Type of control unit programming:

Control unit programming using the ‘Campaign’
function in the additional menu on the PIWIS Tester
by entering a programming code.

Programming code:

M2Q3S

Programming sequence:

Read and follow the information and instructions on
the PIWIS Tester during the guided programming
sequence.
During the programming sequence, the high-voltage
power electronics control unit is re-programmed and
then automatically re–coded.
Do not interrupt programming.

Programming time (approx.):

5 minutes

Software release programmed during this
action:

• High-voltage power electronics control unit
Software release: 0071 / 0072 (or higher)
Upon completion of the control unit programming,
the software release can be read out from the relevant
control unit using the PIWIS Tester in the menu ⇒
‘Incremented identifications’.

2

Procedure in the event of error messages
appearing during the programming
sequence:

For work procedure, see:
⇒ Workshop Manual '9X00IN Basic instructions and
procedure for control unit programming using the
PIWIS Tester'

Procedure in the event of a termination in
the control unit programming:

Repeat control unit programming by re-entering the
programming code.

Re-program PSM control unit.
The basic procedure for control unit programming is described in the Workshop Manual. ⇒ Workshop
Manual '9X00IN Basic instructions and procedure for control unit programming using the PIWIS Tester'
For specific information on control unit programming during this campaign, see the table below.

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Required PIWIS Tester software release:

43.200.041 (or higher)

Type of control unit programming:

Control unit programming using the ‘Campaign’
function in the additional menu on the PIWIS Tester
by entering a programming code.

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Programming code:

G4A8Y

Programming sequence:

Read and follow the information and instructions on
the PIWIS Tester during the guided programming
sequence.
During the programming sequence, the PSM control
unit is re-programmed and then automatically
re–coded.
Do not interrupt programming.

Programming time (approx.):

14 minutes

Software release programmed during this
action:

• PSM control unit
Software release: 0192 (or higher)
Upon completion of the control unit programming,
the software release can be read out from the relevant
control unit using the PIWIS Tester in the menu ⇒
‘Incremented identifications’.

3

Procedure in the event of error messages
appearing during the programming
sequence:

For work procedure, see:
⇒ Workshop Manual '9X00IN Basic instructions and
procedure for control unit programming using the
PIWIS Tester'

Procedure in the event of a termination in
the control unit programming:

Repeat control unit programming by re-entering the
programming code.

Read out all fault memories process and delete existing faults if necessary.
Information
If control units are found to have faults that are not caused by control unit programming, these must
first be located and corrected. This work cannot be invoiced under the workshop campaign number.

4
5
6

End the diagnostic application. Switch off ignition. Disconnect P90999 - PIWIS Tester 4 from the
vehicle.
Switch off and disconnect the battery charger.

⇒ Workshop Manual '270689 Charge vehicle electrical system battery'
Enter the campaign in the Warranty and Maintenance logbook.

Information
If no programming is available via the Campaign procedures, proceed with Automatic update procedures for
each control unit as described below.

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Technical Information

2025

Re-programming high-voltage power electronics and PSM control unit
Work Procedure: 1

Re-program control unit for high-voltage power electronics.
The basic procedure for control unit programming is described in the Workshop Manual. ⇒ Workshop
Manual '9X00IN Basic instructions and procedure for control unit programming using the PIWIS Tester'
For specific information on control unit programming during this campaign, see the table below.
Required PIWIS Tester software release:

43.200.041 (or higher)

Type of control unit programming:

Control unit programming using the 'A utomatic
programming' function of the control unit for
high-voltage power electronics:
"High-voltage power electronics" control unit
– "Coding / Programming" menu – "Automatic
programming" function.

Programming sequence:

Read and follow the information and instructions on
the PIWIS Tester during the guided programming
sequence.
During the programming sequence, the high-voltage
charger control unit is re-programmed and then automatically re-coded.
Do not interrupt the programming and coding
process.
Once the control units have been programmed and
coded, you will be prompted to switch the ignition off
and then back on again after a certain waiting time.
Backup documentation of the new software versions
is then performed.

2

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The programming sequence takes (approx.):

5 minutes

Software release programmed during this
action:

• High-voltage power electronics control unit
Software release: 0071 / 0072 (or higher)

Procedure in the event of error messages
appearing during the programming
sequence:

For work procedure, see:
⇒ Workshop Manual '9X00IN Basic instructions and
procedure for control unit programming using the
PIWIS Tester'

Procedure in the event of a termination in
the control unit programming:

Repeat control unit programming by restarting
programming.

Re-program PSM control unit.

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The basic procedure for control unit programming is described in the Workshop Manual. ⇒ Workshop
Manual '9X00IN Basic instructions and procedure for control unit programming using the PIWIS Tester'
For specific information on control unit programming during this campaign, see the table below.
Required PIWIS Tester software release:

43.200.041 (or higher)

Type of control unit programming:

Control unit programming using the ‘Automatic
programming’ function of the PSM control unit:
‘PSM’ control unit – ‘Coding/programming’ menu –
‘Automatic programming’ function.

Programming sequence:

Read and follow the information and instructions on
the PIWIS Tester during the guided programming
sequence.
During the programming sequence, the PSM control
unit is re-programmed and then automatically
re–coded.
Do not interrupt the programming and coding
process.
Once the control units have been programmed and
coded, you will be prompted to switch the ignition off
and then back on again after a certain waiting time.
Backup documentation of the new software versions
is then performed.

3

The programming sequence takes (approx.):

14 minutes

Software release programmed during this
action:

• PSM control unit
Software release: 0192 (or higher)

Procedure in the event of error messages
appearing during the programming
sequence:

For work procedure, see:
⇒ Workshop Manual '9X00IN Basic instructions and
procedure for control unit programming using the
PIWIS Tester'

Procedure in the event of a termination in
the control unit programming:

Repeat control unit programming by restarting
programming.

Press •F3“ to start the integration test in the control unit selection.
All affected control units should now be successfully programmed or checked in the control unit
overview and their status.

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Technical Information

2025

Information
Cycle the electric parking brake switch after the programming sequence has completed successfully to
clear the warning in the instrument cluster.
If a deviation in the integration test is still indicated despite programming being carried out, this must be
repeated. If the deviation persists, contact Technical Support.
4

Read out all fault memories process and delete existing faults if necessary.
Information
Cycle the electric parking brake switch after the programming sequence has completed successfully to
clear the warning in the instrument cluster.
If control units are found to have faults that are not caused by control unit programming, these must
first be located and corrected. This work cannot be invoiced under the workshop campaign number.

5
6
7

End the diagnostic application. Switch off ignition. Disconnect P90999 - PIWIS Tester 4 from the
vehicle.
Switch off and disconnect the battery charger.

⇒ Workshop Manual '270689 Charge vehicle electrical system battery'
Enter the campaign in the Warranty and Maintenance logbook.

Warranty processing
Information
The specified labor times were determined specifically for carrying out this campaign and include all
necessary preliminary and subsequent rework. The labor time may differ from the labor time published in the
Labor Operation List in the PCSS.
Scope 1:

Re-programming high-voltage power electronics and PSM control unit
Labor time:
Re-programming high-voltage power electronics and PSM control unit
Includes:
Connecting and disconnecting battery charger
Connect and disconnect PIWIS Tester
Reading out and deleting fault memories
⇒ Damage number WSC7 066 000 1

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Labor time: 55 TU

Service

Technical Information

2025

ENU

WSC7

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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.

© 2025 Porsche Cars North America, Inc.

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