Service

Technical Information

99/25

ENU

4810

4

Temporary Vibrations on the Steering Wheel, Particularly During Sporty Driving (99/25)
Vehicle Type:

911 GT3 (992)
911 GT3 with Touring package (992)
911 GT3 RS (992)

Model Year:

As of 2021

Concerns:

Power steering control unit (EPS)

Cause:

The customer complains that there are temporary vibrations on the steering wheel in certain driving situations. This fault type can occur in particular during sporty driving.

Action:

If there is a customer complaint, check the software release of the power steering control unit and
re-program or recode the power steering control unit (EPS) using the Porsche Tester depending on the
software release.
Information
The minimum programming / coding requirement is the PIWIS Tester software release 43.800.000 (or
higher)

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'

Check software release of the power steering (EPS) control unit.
Work Procedure: 1

2

Perform general preliminary work for control unit programming accordingly.
⇒ Workshop Manual '9X00IN Basic instructions and procedure for control unit programming - section
on "Preliminary work"'
Check software release of the power steering control unit (EPS).
2.1

In the Control unit selection 'Overview', select the ‘Power steering’ control unit and confirm with
•F12“ (‘Next’).

2.2

Select the 'Extended identifications' tab and check the software release.

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Service
4810

ENU

Technical Information

99/25
Assessment
The software release is lower than
“0440”.

Action
Re-program power steering control unit (EPS).
As part of the programming sequence, the
necessary coding takes place automatically.
Continue with:
⇒ Technical Information '9X00IN
Re-programming power steering control unit'

The software release is "0440" (or
higher).

Re-code the power steering (EPS) control unit.
Continue with:
⇒ Technical Information '9X00IN Re-coding
power steering control unit'

Re-programming the 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'
Specific information on control unit programming during this action:
Required Porsche Tester software release:

43.800.000 (or higher)

Type of control unit programming:

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

Programming sequence:

Read and follow the information and instructions
on the Porsche 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:

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Programming takes up to 5 minutes, depending on
equipment.

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Service

Technical Information

99/25

Software programmed during this action:

ENU

4810

4

• Power steering control unit (EPS)
Software release: 0440 (or higher)
Following control unit programming, the software
release can be read out from the respective control
unit using the Porsche Tester in the menu ⇒
‘Extended identifications’.

Procedure if error messages appear during the
programming sequence:

⇒ Workshop Manual '9X00IN Basic instructions

Procedure in the event of termination of control
unit programming:

Repeat control unit programming by restarting
programming.

and procedure for control unit programming using
the PIWIS Tester'

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 vehicle electrical system battery'
End of action.

Re-coding the power steering control unit (EPS)
Work Procedure: 1

Re-code the power steering control unit (EPS).
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:

43.800.000 (or higher)

Type of control unit coding:

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

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Technical Information

99/25

Coding sequence:

Read and follow the information and instructions on
the Porsche Tester during the guided procedure.
Do not interrupt coding.
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 vehicle electrical system battery'

Labor position and PCSS encryption
Labor position:
APOS

Labor operation

I No.

48902541

Re-coding the power steering control unit (EPS)

48902542

Re-programming the power steering control unit
(EPS)
PCSS encryption:

Location (FES5)

48100

Steering wheel

Damage type (SA4)

1313

vibrating, shaking

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.

Dec 17, 2025
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