Symptom-based workshop manual

Service
07/26 ENU

2440

2

Combustion Misfiring/Irregular Engine Running During Catalytic Converter Heating Phase and Yellow
Malfunction Indicator Light (MIL) Active (SY 07/26)
Vehicle Type:

Panamera 4 E-Hybrid (YAA/YAB)
Panamera 4S E-Hybrid (YAA/YAB)

Model Year:

As of 2024 up to 2025

Information:

DME control unit

Symptom:

The customer is complaining about irregular engine running during the catalytic converter heating phase
and the yellow malfunction indicator light (MIL) on the instrument cluster lighting up.
One or more of the following fault memory entries is stored in the DME control unit fault memory:
•
•
•
•
•
•
•

Cause:

P030000 - Misfire detected (0027DB)
P030100 - Misfire cylinder 1 (00295F)
P030200 - Misfire cylinder 2 (002960)
P030300 - Misfire, cylinder 3 (002961)
P030400 - Misfire, cylinder 4 (002962)
P030500 - Misfire, cylinder 5 (002963)
P030600 - Misfire, cylinder 6 (002964)

Combustion misfiring can occur during the catalytic converter heating phase due to coking of the fuel
injectors.
Information
The catalytic converter is in the heating phase at:

Remedial
Action:

•

Cold start of the combustion engine

•

Restarting the combustion engine after a pure electric drive

Create the vehicle analysis log (VAL) and check measured values of the stored fault memory entries.
If the fault memory entry was stored or occurred during the catalytic converter heating phase, re-program
the DME control unit with the Porsche Tester.
Information
Minimum programming requirement is the Porsche Tester software release: 43.800.030 (or higher).

Required tools
Tools
Information:

•
•

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

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Symptom-based workshop manual

07/26

battery chargers to be used, see the corresponding Workshop Manual. ⇒ Workshop Manual '270689
Charge battery and vehicle electrical system'

Creating vehicle analysis log (VAL) and checking measured values of stored fault memory entries
Work Procedure: 1

2

Create vehicle analysis log (VAL).
1.1

Connect and switch on the battery charger.
⇒ Workshop Manual '270689A4 Charge battery and vehicle electrical system'

1.2

Place original remote control in emergency start tray.

1.3

Connect P90999 - Porsche Tester 4, switch on the ignition and start the diagnostic application.

1.4

Create vehicle analysis protocol (FAP) and mark it with the attribute “Pre-VAL”.

In the vehicle analysis log (VAL), check the stored fault memory entries in the DME control unit.
2.1

Open vehicle analysis log (FAP)

2.2

Check whether one of the fault memory entries in the DME control unit regarding combustion
misfiring occurred during the catalytic converter heating phase.
To do this, read out the measured value “20_Faults – measured values: engine torque”.
Assessment

Action

The measured value is not between 85
(62.6 ftlb.) and 92 (67.8 ftlb.) Nm.

The fault memory entry did not occur or become
stored during the catalytic converter heating
phase.
The action described in this symptom-based
repair description (SY) is not expedient in this
case.
Continue troubleshooting in some other way.
Note:
Combustion misfiring can also be caused by an
empty tank or by defective injectors, spark plugs
or ignition coils, for example.
End of action.

The measured value is between 85 (62.6
ftlb.) and 92 (67.8 ftlb.) Nm.

The fault memory entry occurred or was stored
during the catalytic converter heating phase.
Continue with:
⇒ Technical Information '270689A4 Program
DME control unit'

Mar 2, 2026
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Symptom-based workshop manual

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07/26 ENU

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Program DME control unit
Work procedure: 1

Re-program DME control unit.
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:

43.800.030 (or higher)

Type of control unit programming:

Control unit programming using the ‘Automatic
programming’ function for the DME control unit:
‘DME’ 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 DME
control unit is re-programmed first, and then the
transmission control unit is re-programmed.
Thereafter, both control units are 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 12 minutes, depending
on equipment.

Software programmed during this action:

See section: ⇒ Technical Information '9X00IN
Overview of programmed DME data records'
Following control unit programming, the software
release can be read out using the PIWIS Tester in
the menu ⇒ ‘Extended identifications’.

2

Procedure if error messages appear 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.

Read out and delete all control unit fault memories.

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Information
If control units are found to have faults that are not caused by control unit programming, they must first
be located and corrected. This work cannot be invoiced under the workshop campaign number.
3

Press •F3“ to start the integration test in the control unit selection.
If there is an integration deviation for individual control units, these must be programmed before vehicle
handover to the customer.
Information
If, despite the programming performed, a deviation is still displayed during the integration test, the test
must be carried out again.
There must be no breaches of integration!
Control units with optional software can be ignored – with the exception of the DME control unit and the
transmission control unit.

4

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

5

Switch off and disconnect the battery charger.
⇒ Workshop Manual '270689 Charging the vehicle electrical system battery'

Overview of programmed DME data records
Information
The software part number and software release of the programmed data record are based on the specified
Porsche Tester software release. Please note that this may be different in a higher release.
Overview:

Panamera 4 E-Hybrid (YAA/YAB):
Exhaust emission
standard

Model year

Porsche part number
(software)

Software release

2024 (R)

2025 (S)

ULEV70

-

X

976907552AN

0001 (or higher)

ULEV70

-

X

976907552BC

0002 (or higher)

Panamera 4S E-Hybrid (YAA/YAB):
Exhaust emission
standard

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Model year

Porsche part number
(software)

Software release

2024 (R)

2025 (S)

ULEV70

-

X

976907552BG

0002 (or higher)

ULEV70

-

X

976907552AS

0001 (or higher)

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Symptom-based workshop manual

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2

Labor position and PCSS encryption
Working position:
APOS

Labor operation

I No.

24702541

Re-programming DME control unit
PCSS encryption:

Location (FES5)

24400

Injector valve

Damage type (SA4)

1613

temporarily not functioning

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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