Service

Technical Information

120/25 ENU

2708

Vehicle Cannot be Charged and Fault Memory Entry for the Additional Coolant Pump in the
High-Voltage Battery Control Unit (120/25)
Change
Overview:

2

Revision

Date

Change

0

03/16/2026

•

First Publication

1

03/30/2026

•

Update to Work Procedure,
Preparatory work

Model Year:

As of 2024 up to 2026

Model Line:

Panamera (YAA / YAB)

Equipment:

Hybrid drive system PHEV (M-No. 0K3)

Concerns:

High-voltage battery

Cause:

The customer complains that the vehicle can no longer be charged or the malfunction indicator light is
active.
A pin of the high-voltage battery control unit (BECM) can be loosened; therefore, the activation of the additional coolant pump for the low-temperature system (P2) is not possible. This results in potentially insufficient cooling during the charging process, which is why it is aborted or not started.
The following fault memory entry is stored in the fault memory of the high-voltage battery control unit
(BECM):
•

Action:

P0C4700 - additional coolant pump, activation, open circuit (00500A)

Check activation of the additional coolant pump for low-temperature system (P2) and replace the
high-voltage battery if necessary.
Information
The minimum requirement for troubleshooting is the Porsche Tester software release 43.900.000 (or
higher).

AfterSales

Mar 30, 2026
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2

Service

Technical Information

ENU 120/25

2708

Installation
Position:

Installation position of high-voltage battery

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 the battery and vehicle electrical system'

Additional required tools for checking the signal line for the additional coolant pump for the
low-temperature system (P2):
•
•
•
•
•
•
•

Mar 30, 2026
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Commercially available multimeter, e. g. V.A.G 1526E - hand-held multimeter
VAS 6931A - Transmission and engine jack
VAS 6760A - Storage tray
Torque wrench 40-200 Nm (30-248 ftlb.), e. g. V.A.G 1332A - Torque wrench, 40-200 Nm (30-248
ftlb.)
Torque wrench, 2-10 Nm (2-8 ftlb.), e.g., V.A.G 1783 - Torque wrench, 2-10 Nm (2-8 ftlb.)
Torque wrench, 0.4-2 Nm (0.3-1.5 ftlb.), e. g. VAS 6253A - Torque wrench, 0.4-2 Nm (0.3-1.5 ftlb.)
Torque wrench, 6-50 Nm (4.5-37 ftlb.), e. g. V.A.G 1331A - Torque wrench, 6-50 Nm (4.5-37 ftlb.)

AfterSales

Service

Technical Information

120/25 ENU

2708

2

Additional required tools for checking the signal line for the additional coolant pump for low-temperature
system (P2) [only for vehicles with central wheel lock (M-no.: 1PJ):
•
•
•

9794 - Assembly aid
VAS 6266A - Wheel fitting trolley
Torque wrench 150-600 Nm (111-443 ftlb.), e. g. V.A.G 1601 - Torque wrench 150-800 Nm
(111-590 ftlb.)

Additional required tools for replacing the high-voltage battery:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

P90076 - Scissor lift table mount
VAS 6410 - Contact surface cleaning set
VAS 6832 - Master Gear unit elevating platform
VAS 6883A - Insulated tool set
9890 - Socket wrench E12
VAS 6890 - Spring band clamp pliers
High-voltage testing module
VAS 6558A/27 - Set of Kelvin clamps and test probes
VAS 6931A - Transmission and engine jack
VAS 6760A - Storage tray
VAS 531 011 - Cooling system service equipment
Torque wrench 40-200 Nm (30-248 ftlb.), e. g. V.A.G 1332A - Torque wrench, 40-200 Nm (30-248
ftlb.)
Torque wrench, 2-10 Nm (2-8 ftlb.), e.g., V.A.G 1783 - Torque wrench, 2-10 Nm (2-8 ftlb.)
Torque wrench, 0.4-2 Nm (0.3-1.5 ftlb.), e. g. VAS 6253A - Torque wrench, 0.4-2 Nm (0.3-1.5 ftlb.)
Torque wrench, 6-50 Nm (4.5-37 ftlb.), e. g. V.A.G 1331A - Torque wrench, 6-50 Nm (4.5-37 ftlb.)

Required parts and materials as needed
Information
No parts and materials are required for the initial test of the additional coolant pump for the low-temperature
system (P2) with the Porsche Tester.
Parts
Information:

Part No.

Designation
– Location of use

Quantity

Required parts for checking the signal line for the additional coolant pump low-temperature system
(P2):
976253725A

⇒ Clamp
– Left exhaust system

1 piece(s)

976253725C

⇒ Clamp
– Right front seat

1 piece(s)

AfterSales

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Technical Information

ENU 120/25

2708

N 90788402

⇒ Fitting screw M 6 x 9 x 16
– Rear apron

2 piece(s)

Additional parts and materials required if the high-voltage battery must be replaced:
976915099 XX*

⇒ Hybrid battery
– Rear apron

1 piece(s)

PAG010006C XXX*

⇒ Information plate
– High-voltage battery

1 piece(s)

PAB010006B XXX*

⇒ Information plate
– High-voltage battery

1 piece(s)

PAB121809

⇒ Seal
– Coolant reservoir for low-temperature system

1 piece(s)

V04015003P

⇒ Coolant additive
– Low-temperature system

0.1 piece(s)

*Determine the variant of the high-voltage battery and the warning stickers required for the respective
vehicle using the vehicle identification number in the Porsche Spare Parts Catalogue (PET2).

Preparatory work
Work Procedure: 1

Check function of additional coolant pump for low-temperature system (P2).
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 and mark it with the attribute “Pre-VAL”.

1.5

Actuate additional coolant pump for low-temperature system (P2) via high-voltage battery
control unit (BECM).
Assessment

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Action

( )

Additional coolant pump for
low-temperature system (P2) can
be activated and is working.

Function OK.
Continue troubleshooting otherwise.
End of action.

✗)
(✗

Additional coolant pump for
low-temperature system (P2) cannot
be activated.

Continue with Step ⇒ 2.

AfterSales

Service

Technical Information
2

120/25 ENU

2708

2

Check production date of the high-voltage battery.
To do this, read out the value "Vehicle central information system (FAZIT) - identification" from the
Extended identifications menu for the high-voltage battery control unit.
Information
Example of measured value:
•

MZS-MST25.09.2325560144

The first 6 digits are the production date. In this example 25.09.2023.
Assessment
•
•

Action

Production date of the high-voltage
battery is 07/27/2025 or later

Continue troubleshooting otherwise.

Production date of the high-voltage
battery is 07/26/2025 or earlier

Check signal line for additional coolant pump for
low-temperature system (P2)
Continue with. ⇒ Technical Information '270689A4
Check signal line for additional coolant pump for
low-temperature system (P2)'

End of action.

Check signal line for additional coolant pump for low-temperature system (P2)
Work Procedure: 1

2

Observe general warning notes for working on the high-voltage vehicle electrical system.
⇒ Workshop Manual '2X00INB2 General warning notes for working on the high-voltage vehicle electrical system'
Isolate HV system.

⇒ Workshop Manual '277583A1 Deactivation/start of the high-voltage system'

3

Complete the documentation.
Procedure, see: ⇒ Workshop Manual '2775INA4 Test log: Verifying isolation from the power supply'

4

Remove heat protection plate for left rear muffler.
Procedure see: ⇒ Workshop Manual '261420A3 Removing and installing heat protection plates'

5

Expose additional coolant pump for low-temperature system (P2).
Procedure see: ⇒ Workshop Manual '194519D7 Removing and installing additional coolant pump for
low-temperature system (P2) - 0K3'

AfterSales

Mar 30, 2026
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2

Service

Technical Information

ENU 120/25

2708
6

Release and disconnect electric plug connection for
Þ Electric plug connection on
high-voltage battery⇒
high-voltage battery -1-.

Electric plug connection on
high-voltage battery
7

Release and disconnect electric plug connection of
Þ Additional coolant pump
additional coolant pump P2⇒
low-temperature system P2 -2-.

8

Perform resistance test on signal line for additional
coolant pump for low-temperature system (P2).

9

8.1

Set the multimeter to “resistance test”.

8.2

Position measuring tip 1 of multimeter on
electric plug connection for high-voltage
battery pin 6 (blue / grey).

8.3

Position measuring tip 2 of multimeter on
electric plug connection for additional coolant
pump for low-temperature system P2 pin 2
(blue / grey) .

Additional coolant pump
low-temperature system P2

Assess measured value.
Assessment
( )

Resistance of the signal line is normal or
unremarkable (< 0.5 Ω).

Action
Signal line OK.
•
•

Mar 30, 2026
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AfterSales

Connect electric plug connection for additional coolant pump for low-temperature
system P2, until it locks securely.
Replace high-voltage battery. ⇒ Workshop
Manual '270855A3 Replace the high-voltage
battery'

Service

Technical Information

120/25 ENU

2708

2

End of action.
✗)
(✗

Resistance of the signal line is too high
or signal line is interrupted (> 0.5 Ω /
O.L.).

Signal line damaged or interrupted.
Locate damage, repair line and then complete the
vehicle again.
End of action.

Information
The fault pattern described here is caused by a
Þ Plug contact for high-voltage
pushed-back PIN ⇒
battery control unit -1- in the high-voltage battery
Þ Plug contact for high-voltage
control unit (BMCE)⇒
battery control unit -2-. This control unit is integrated
into the high-voltage battery.
There is currently no approval for a separate
replacement of the high-voltage battery control unit
(BMCE) for the Panamera (YAA/YAB).
If the PIN is damaged or pushed back, the entire
high-voltage battery including the integrated control
unit (BMCE) must therefore be replaced:

Plug contact for high-voltage
battery control unit

Labor position and PCSS encryption
Labor position:
APOS

Labor operation

I No.

19450140

Check additional coolant pump low-temperature
system, (activation)

19450141

Check additional coolant pump low-temperature
system (activation, read measured values)

19450142

Check additional coolant pump low-temperature
system (signal line)

27085540

Replace the high-voltage battery

AfterSales

Mar 30, 2026
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2

Service
2708

Technical Information

ENU 120/25

PCSS encryption:
Location (FES5)

27080

High-voltage battery

Damage type (SA4)

4011

Loose contact, contact fault

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.

Mar 30, 2026
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