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Spare Parts Requirements for High-Voltage Components: Additional Insulation
Measurement Before Starting Vehicle: Observe Specified Procedure (74/21)
Model Series:

Taycan (Y1A / Y1B / Y1C)

Model Year:

As of 2020

Concerns:

High-voltage system

Information:

To prevent additional damage to the high-voltage system, which cannot be diagnosed during standard
fault finding, a separate insulation measurement must be carried out after a repair on the high-voltage
system before starting up the vehicle.
This measurement prevents consequential damage to the high-voltage components when the vehicle is
restarted.

Action required: Perform separate insulation measurement after repairs and before starting the vehicle.
This measurement is performed using the PIWIS Tester Application --> Measuring Equipment -->
Measuring Program.
Information
Performing insulation measurement at the charging socket is not enough.

Preparatory work
WARNING
Incorrect handling of high-voltage components
•

Electric shock

•

Short circuit

•

Fire

•

Explosion



Only appropriately trained and authorized persons are permitted to work on high-voltage vehicles and
components.



Required qualification: High voltage technician or high voltage expert.



Observe national requirements and legislation for this work.



Always use insulated tools, e.g. VAS 6883 Insulated Tool Set when working on these components.



Observe general warning notes for working on the high-voltage system.  Workshop Manual '2X00IN
General warning notes for working on the high-voltage system'

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Work Procedure: 1

Technical Information

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Read the warning notices.  Workshop Manual '2X00IN General warning notes for working on the
high-voltage vehicle electrical system'

2

Isolate the high-voltage system from the power supply and complete the relevant documentation. 
Workshop Manual '2X00IN Isolating high-voltage system from power supply / starting high-voltage
system'

3

Remove rear luggage compartment trim panel.  Workshop Manual '70061900 Removing and
installing (centre) luggage compartment trim panel (luggage compartment cover)'
Information
The test adapters at the charging sockets can differ from country to country.

4

Perform function test on test adapter.  Workshop Manual '2X00IN Function test on high-voltage
test adapter'

Overview of high-voltage system

Overview of high-voltage system
2
3
4

– E-box
– High-voltage distributor
– High-voltage charger

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6
7
8
9
10
11

–
–
–
–
–
–
–

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Voltage converter
Air-conditioning compressor
Interior heater
Front power electronics
Electric drive motor
Rear power electronics
Electric machine

Perform insulation measurement
WARNING
Incorrect handling of high-voltage components
•

Electric shock

•

Short circuit

•

Fire

•

Explosion



Only appropriately trained and authorized persons are permitted to work on high-voltage vehicles and
components.



Required qualification: High voltage technician or high voltage expert.



Observe national requirements and legislation for this work.



Always use insulated tools, e.g. VAS 6883 Insulated Tool Set when working on these components.



Observe general warning notes for working on the high-voltage system.  Workshop Manual '2X00IN
General warning notes for working on the high-voltage system'

Information
Insulation measurements are performed and no resistance measurements are performed (check tester
setting).
NOTE: The terms Isolation and Insulation are often used interchangeably in Porsche documentation.
For example, to find the source of an isolation fault using VAS 6558A, select the HV Isolation
Measurement program to measure HV insulation resistance.
Work
Procedure:

•
•
•

The measurements must be performed using 9900 - PIWIS Tester 3 and a high-voltage testing
module.
To obtain the required measuring resistance, the measuring voltage must be present on the insulation tester until a stable measured value is displayed.
Two measurements must always be performed for each measuring point. Positive terminal on
shielding and negative terminal on shielding.

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A measurement is only regarded as being within the setpoint value range if both measured values
(positive terminal on shielding and negative terminal on shielding) are within the specified range.

Each insulation measurement must be performed four times because diodes are installed in the
high-voltage system.
High-voltage positive to shielding and high-voltage
negative to shielding.

Measurement 1 and 2 (sample result)
Shielding to high-voltage positive and shielding to
high-voltage negative.

Measurement 3 and 4 (sample result)
Information
The special tool number of the test adapter can differ from country to country. (VAS 6558/10–2,
VAS 6558/18A, VAS 6558/13A or VAS 6558/22)
1

Determine the result for measurement 1 (DC
high-voltage line from high-voltage distributor
to DC charging socket).
1.1

Connect charging socket test adapter VAS
6558/10–2 (DC) to the DC charging socket.

1.2

Set test voltage of the tester to 1,000 V.

1.3

Perform measurement 1 and record the
result.
Nominal value > 1.1 M
Right charging socket

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Information
The special tool number of the test adapter can differ from country to country. (VAS 6558/10–1,
VAS 6558/14A or VAS 6558/17A)
2

Determine the result for measurement 2 (AC
high-voltage line from high-voltage distributor
to AC charging socket).
2.1

Connect charging socket test adapter VAS
6558/10–1 (AC) to the left charging socket.

2.2

Set test voltage of the tester to 500 V.

2.3

Perform measurement 2 and record the
result.
Setpoint values: > 1,1 MΩ
Left charging socket

3

Determine the result for measurement 3 of the
high-voltage line (from high-voltage distributor
to passenger compartment heater) to the
high-voltage distributor.
3.1

Connect VAS 6558/9-6A - high-voltage
test adapter between high-voltage
distributor and high-voltage line (from
high-voltage distributor to passenger
compartment heater).

3.2

Set test voltage of the tester to 1,000 V.

3.3

Perform measurement 3 and record the
result.

High-voltage distributor

Setpoint values: > 1,1 MΩ

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Lift up body cover  Body cover -1- to allow access
to the high-voltage line for the electric machine at the
rear using a plastic wedge and remove it.

Body cover
Information
Wear gloves with cut protection when loosening and detaching the traction line.
5

Unscrew fastening screws  Rear power electronics
traction line -1- for the connection for the rear power
electronics traction line and disconnect them.

Rear power electronics traction line
6

Determine the result for measurement 4 of
the traction line (from E-box to rear power
electronics).
6.1

Connect HV test adapter to the traction line
(from E-box to rear power electronics).

6.2

Set test voltage of the tester to 1,000 V.

6.3

Perform measurement 4 and record the
result.
Setpoint values: > 1,1 MΩ
Rear power electronics traction line

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Information
A separate traction line is required as a special tool for the following measurement. If this is not yet
available in the workshop, it must be ordered.
Part number: 9J1971015B - Traction line
7

Guide one end of the separate traction line through
the opening from the luggage compartment floor and
connect it to the rear power electronics.

Rear power electronics traction line
8

Determine result for measurement 5 of the
traction line (rear power electronics - E-box).
8.1

Connect high-voltage measuring adapter
to the other end of the separate traction line.

8.2

Set test voltage of the tester to 1,000 V.

8.3

Perform measurement 5 and record the
result.
Setpoint values: > 5 MΩ
Traction line
Result of check

Action

( )

All measurements are within the
required range.

End of test.
The high-voltage system is OK and can be commissioned.

(✗)

One or more measurements are not
within the required range.

If an insulation fault in the high-voltage system is
found during insulation measurement, the identification of the damaged component must be carried
out fully for the affected areas (front or rear end).
For instructions, see:
 Workshop Manual '2X00IN Insulation fault finding'

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Concluding work
Work Procedure: 1

Remove all adapters and plug in and lock all electrical plug connections.

2

Position body cover  Removing body cover -1- to
allow access to the high-voltage line for the electric
machine at the rear and clip it in.

3

Install rear luggage compartment trim panel. 
Workshop Manual '70061900 Removing and
installing (centre) luggage compartment trim panel
(luggage compartment cover)'

4

Start the high-voltage system.  Workshop Manual
'2X00IN Isolating high-voltage system from power
supply / starting high-voltage system'

Removing body cover

Invoicing
Information
The tests must be fully documented and verifiable.
For technical reasons, it is not possible to define a fixed working time under 2X00 for this work. For this
reason, a "once-off labor operation" must be created for invoicing this work using the following data:
•

Labor operation number: 270803

•

Description: Additional insulation measurement following vehicle repairs (TI 74/21)

•

Time units: max. 200 TU

Invoicing:

For documentation and warranty invoicing, enter the relevant Customer service ID (FES5) of the
component responsible for causing the problem, in combination with the damage category (SA4).

References:

 Workshop Manual '2X00IN General warning notes for working on the high-voltage vehicle electrical
system'

 Workshop Manual '2X00IN Isolating high-voltage system from power supply / starting high-voltage
system'

 Workshop Manual '2X00IN Function test on high-voltage test adapter'
 Workshop Manual '2X00IN Insulation fault finding'
 Workshop Manual '70061900 Removing and installing (centre) luggage compartment trim panel
(luggage compartment cover)'

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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.

© 2022 Porsche Cars North America, Inc.

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