Service

Technical Information

2025

ENU

WSF7

4

WSF7 - Re-Program Power Steering Control Unit (EPS) (Workshop Campaign)
Important:

CRITICAL WARNING -This campaign includes steps where control unit(s) in the vehicle will be programmed
with the PIWIS Tester. The vehicle voltage must be maintained between 13.5 volts and 14.5 volts during this
programming. Failure to maintain this voltage could result in damaged control unit(s). Damage caused by
inadequate voltage during programming is not a warrantable defect. The technician must verify the actual
vehicle voltage in the PIWIS Tester before starting the campaign and also document the actual voltage on the
repair order.

Model Year:

2025

Model Line:

911 (992)

Concerns:

Power steering control unit (EPS)

Cause:

On the affected vehicles, there is a possibility that briefly fluctuating vehicle electrical system voltages
may occur when the engine is started. This could cause a function test of the power steering control unit to
fail.
If this is the case, this causes a reduction in the power steering and the yellow warning message "Power
steering reduced, onward driving possible" appears in the instrument cluster.

Action:

Re-program power steering (EPS) control unit via PIWIS Tester.
Information
The minimum programming requirement is the PIWIS Tester software release 43.400.030 (or higher).

Affected
Vehicles:

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

Required tools
Tools:

•
•

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'

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Jul 10, 2025
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4

Service
WSF7

ENU

Technical Information

2025

Re-programming power steering control unit (EPS)
Work procedure: 1

Re-program power steering control unit (EPS).
The basic work 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:

43.400.030 (or higher)

Type of control unit programming:

Control unit programming using the "Automatic
programming" function of the control unit:
"Power steering (EPS)" 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 control
unit is re-programmed and then automatically
re-coded.
Do not interrupt the programming and coding
process.
Backup documentation for the re-programmed
software releases starts after programming.

Programming duration:

Programming takes up to 5 minutes, depending on
the equipment.

Software programmed during this campaign:

• Power steering (EPS)
Software release: 0190 (or higher)
Following control unit programming, the software
release can be read out from the relevant control
unit using the PIWIS Tester in the menu ⇒ "Incremented identifications".

Jul 10, 2025
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Procedure in the event of error messages
appearing during the programming sequence:

⇒ 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.

AfterSales

Service

Technical Information
2

2025

ENU

WSF7

4

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

3

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

4

Switch off and disconnect the battery charger.

5

Enter the campaign in the Warranty and Maintenance Logbook.

Warranty processing
Information
The stated labor time was determined specifically for carrying out this campaign and includes all necessary
preliminary work and rework. The labor time can differ from the labor time published in the Labor Operation
List in the PCSS.
Scope 1:

Re-programming power steering control unit (EPS)
Labor time:
Re-programming power steering control unit (EPS)
Includes:
Connecting and disconnecting battery charger
Connecting and disconnecting PIWIS Tester
Read out and delete fault memory

Labor time: 37 TU

Þ Damage code WSF7 066 000 1
⇒

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.

AfterSales

Jul 10, 2025
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