Bulletin #: 2217

Advanced Technical Information

Part ID: 9035

9

Taycan – Troubleshooting HV Faults
Vehicles Affected
Models

Model Year

Model Type

VIN Range

Vehicle-Specific Equipment

Taycan

As of 2020 up to 2022

Y1A, Y1B, Y1C

N/A

N/A

Revision History
Revision

Release Date

Changes

0

June 15, 2022

Original document

Condition
The following document aims to assist Porsche Dealership service and support personnel with diagnosis of select
fault codes pertaining to high-voltage systems. This document will be updated and re-published when new
information becomes available.
Feedback on any existing documentation (the Workshop Manual or Guided Fault Finding, for example) is highly
encouraged.
Please submit any feedback via PRMS: https://ppn.porsche.com/portal/community/porsche_cars_
north_america/after_sales/support/blog/2020/11/11/information-media-error-reporting-and-feedback-to-doc
ument-function

Technical Background
Self-diagnosis and monitoring routines within the PIWIS Tester, the vehicle, vehicle systems, and control units can
result in erroneous Fault Codes, DTCs, or warnings.

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Bulletin #: 2217

Advanced Technical Information

Part ID: 9035

Service Information
Diagnosis should be performed using the information contained here in conjunction with existing diagnostic
information and tools (e.g. the Workshop Manual, published TIs, and Guided Fault Finding).
Diagnostic Tip #1
Thermal Management (TME) CU Fault Code B182D16 “Electric interior heater (HV-PTC) 800 V electronics voltage too low.” This fault appears often when the HV system does not start, but rarely indicates a real issue.
Focus next diagnostic steps on figuring why the HV system is not starting.
Diagnostic Tip #2
The Gateway control unit (Part ID 9035) is the High Voltage Coordinator in the Taycan. There are many Gateway
actual values available for information, but fault codes stored in the Gateway will typically reveal what is preventing
the HV system from starting. Knowing the complete FC + DTC title helps identify a diagnostic starting point.
Example: Gateway Fault U112300, “Data bus – fault value received.”
This fault appears vague at first glance, but there is valuable information available when viewing diagnostic
information based upon the specific Diagnostic Trouble Code (DTC). There are over 60 different DTC’s for FC
U112300.
E.g. U112300-FF0008, “No_Component_Function_BMS”, indicates the HV system does not start due to HV
battery control is not functioning correctly.
Refer to Appendix A at the end of the document for a list of HV-related Gateway faults including DTCs. Each fault
and sub-fault/DTC contains a title that provides valuable information about the status of the HV systems.
Diagnostic Tip #3
Some HV faults cause the HV Battery to enter “Emergency Off” mode whereby the HV system locks and prevents
the vehicle from starting.
Faults that cause the vehicle to enter Emergency Off mode can be serious (Cell Voltage Limit Reached, for example),
while some faults can be erroneous (faults that set due to a mishandled 12V jump-start, for example).
Example: several occurrences of Gateway Fault U112300, “Data bus – fault value received”, including U112300FF0044. The DTC information in Appendix A lists this fault as, “UCell_UL_Failure_HV Battery”.
With the complete fault title, the technician sees there is a Fault + DTC indicating why the HV system entered
Emergency Off mode.

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Advanced Technical Information

Part ID: 9035

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Note: It is possible to erase all faults from the HV battery and for the “Emergency Off” mode to remain active in the
HV battery. Switching the HV system back on requires a reset function with the PT3G.
With PT3G, go to BMS (High-Voltage Battery CU) --> Drive Links --> Resetting cell module deactivation. If the HV
systems are fully functional and healthy, the vehicle can then be switched on and driven.
Diagnostic tip #4
It is important to understand various scenarios and errors that can occur during 12V jump-starting.
•
Always use the approved Deutronic power supply (VAS 5908) to jump-start a Taycan, when possible.
•
The HV system normally provides energy to recharge the 12-volt battery. If the HV system has errors and

does not activate, then it will not charge the 12-volt battery.
•
Ensure the 12-volt battery recharges by the HV system or an external power supply.
•
If the vehicle must be jump-started using a jump box, be sure to switch on the vehicle and confirm the HV

system is active immediately after energizing the 12-volt system. As the 12-volt battery was extremely

low on charge, it will not keep the car powered up for long (sometimes only a few seconds, for example –

it depends on how deeply the 12-volt battery is discharged)
•
Observe existing workshop manual and technical information documents concerning jump-start of the 12-
volt battery.
•
Do not leave a jump box connected after the 12-volt battery is re-activated. Even a fully charged jump box

may have a lower output voltage than the discharged 12-volt battery; this can result in the jump box

actually bringing the 12-volt battery voltage down, even though it successfully reactivated it.
•
Important: Confirming the HV system is active

If the 12-volt battery indicator (instrument cluster image, below) is red or yellow, the HV system did not

start and the 12-volt system is not charging. Additional warning messages are likely to be displayed.

Figure 2

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Part ID: 9035

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•
If this warning indicator appears after jump-starting, immediately cycle the ignition off and back on again.

It is possible for this error to happen when jump starting, even if the only problem was a discharged battery.

Confirm the errors are gone and the HV system is active. If these warnings and indicator cannot be cleared

after a few ignition cycles, turn off the car and provide an external power supply to the 12-volt battery as

soon as possible.
•
Avoid leaving a jump box connected to the vehicle with the HV system deactivated. If the 12-volt battery

contactor opens again, then the electrical system is powered only by the jump box. Once the system voltage

becomes low, a wide variety of erroneous faults will set, and it can take a lot of working time to recover. For

example, the HV battery erroneously sets faults for cell overvoltage and undervoltage, and the HV system is
then locked.
Diagnostic tip #5
•
If the 12-volt battery is able to switch on the ignition, then it is likely not an underlying issue with the

vehicle. If it has enough power to turn on the vehicle lights, then it has enough power to activate the HV

system. Do not incorrectly associate HV system errors with the 12-volt battery.
•
Keep the customer’s complaint in consideration. If the complaint is a no-start with multiple warnings, and

the 12-volt battery became discharged later, then the 12-volt battery did not likely cause the problem.

Therefore, it is recommended to recharge the 12-volt battery and continue diagnosing the HV system.
Diagnostic tip #6
•
Not all fault codes which can be stored in a control unit are indicating a failure. During vehicle and vehicle

software development, all similar messages are categorized as A) Faults, B) Development Faults, or C) Notes

or Notices (“Hinweis”). After the software is implemented in vehicle production, the vehicle control units

compile all three message types into one category: Faults.
•
It is important to note many faults are intended as informational notices; they are usually “Hinweis_Prio 6”

in the fault code freeze-frame data. Actual fault codes are typically Priority 1 through 4.
•
Examples from the High-Voltage Charger (On-Board Charger, OBC):

U15AC00 - Signal damping log, Malfunction

U15BF00 - Intelligente Ladefunktion, fehlerhafte Kommunikation

U15AE00 - Quick battery charging (DC), Charging station communication failure

>> These faults are just notices, and can typically be ignored.

>> For example, U15AE00 is normally unrelated to on-board diagnostics, but may become relevant

if there are consistent failures to start charging at multiple DC chargers.
•
The following faults are commonly stored in the On-Board Charger (OBC) of a vehicle that is fully functional

and working as designed.

B200000, B1A88F3, B1A8AF3, P16EF00, P1A3500, P31E900, P31EA00, P33EA00, P33EB00,

P33EF00, P33F000, U112100, U112200, U13AE00, U14CA00, U15A900, U15AB00, U15AC00,

U15AD00, U15AE00, U15AF00, U15B100, U15B300, U15B500, U15BF00, and U15C900
•
Always consider which faults or notices may or may not be relevant to the customer complaint.

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Appendix A: Fault Code Titles
Fault

Sub-Fault

Usable Title (translated)

U112300

91000F

DCDC Converter_No_Component_Function

U112300

FF0006

Operating_Mode_Error_HV Battery

U112300

FF0008

No_Component_Function_HV Battery

U112300

FF0009

Power_Limitation_HV Battery

U112300

FF000A

Service_Disconnect_HV Battery

U112300

FF000B

Interlock(HVIL/Pilot line)_HV Battery

U112300

FF000C

Fault_2_Isolation (insulation resistance)_HV Battery

U112300

FF000D

Fault_1_Isolation (insulation resistance)_HV Battery

U112300

FF0012

Operating_Mode_Error_DCDC Converter

U112300

FF0014

No_Component_Function_DCDC Converter

U112300

FF001A

Operating_Mode_Error_On Board Charger

U112300

FF001C

No_Component_Function_On Board Charger

U112300

FF001D

Interlock(HVIL/Pilot line)_On Board Charger

U112300

FF0025

No_Component_Function_Drive_DME

U112300

FF0026

No_Component_Function_EM_DME

U112300

FF0027

Interlock(HVIL/Pilot line)_EM_DME

U112300

FF0028

section_mode_EM_DME

U112300

FF0029

cutoff_operation_strategy_EM_DME

U112300

FF002A

Interlock(HVIL/Pilot line)_Rear Power Electronics

U112300

FF002B

Discharging_Defect_Rear Power Electronics

U112300

FF0033

Error_HV Heater

U112300

FF0034

Interlock(HVIL/Pilot line)-HV Heater

U112300

FF0035

Internal_Failure-Airbag_Deactived_HV

U112300

FF0038

Airbag_Crash_Type_small

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Advanced Technical Information

Part ID: 9035

Fault

Sub-Fault

Usable Title (translated)

U112300

FF0039

Airbag_Crash_Type_heavy

U112300

FF003B

Airbag_Crash_Type_History_small

U112300

FF003C

Total_Free_Voltage

U112300