Symptom-based workshop manual

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Symptom - Engine - Knocking, Jerking or Vibrations During Acceleration: Checking Fuel
Injectors (SY 41/21)
Model Line:

Cayenne (9YA)
Cayenne Coupé (9YB)

Model Year:

As of 2018

Concerns:

Fuel injector

Symptom:

The customer complains about knocking, jerking or vibrations in the vehicle during acceleration.
This can occur while driving both at partial load and full load.

Cause:

This may be caused by a faulty fuel injector, which can result in misfiring.
No fault codes are stored in the fault memory of the (DME) control unit in this case.

Remedial
Action:

Before replacing a transfer box, a test drive should therefore be performed to rule out the possibility that
the drive train knocking is being caused by an injector. The following diagnostic drive must be performed
for this purpose.

Checking fuel injectors
Work Procedure: 1

2

3

4

Connect 9900 - PIWIS Tester 3 to the vehicle communication module (VCI) via the USB cable.
Then connect the communication module to the vehicle and switch on the PIWIS Tester.
Prepare for test drive.
2.1

Select 'DME control unit', then select
the 'Actual values/input signals' menu.
 Actual values/input signals

2.2

Select the actual value 'Number of misfires
per cylinder' for all cylinders and start
'Data logger' with •F3“.

Test-drive the vehicle by driving in the range in
which the problem occurred (partial load
and/or full load).

Actual values/input signals

If the problem occurs several times, stop the test drive and stop logging.

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Look at the log and check the cylinder misfire counter
during acceleration.  Misfires per cylinder

Misfires per cylinder
Result of check

6

Action required

( )

There is no increase in misfiring on a
cylinder.

End of action required.
Fuel injectors and ignition system OK.

(✗)

There is increased misfiring on a
cylinder.

Continue with Step 6.

Swap the spark plug and ignition coil from the adjacent cylinder with the spark plug and ignition
coil on the affected cylinder, see  Workshop Manual '287020 Removing and installing spark plugs'
and repeat the test drive.
Result of check

7

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Action required

( )

The fault still occurs on the cylinder
that was originally affected.

End of check.
Install a new fuel injector on the original cylinder,
see  Workshop Manual '244019 Removing and
installing fuel injector'.

(✗)

The fault now occurs on the adjacent
cylinder.

Continue with Step 7.

Replace the ignition coil on the cylinder that is now affected with the original ignition coil, see 
Workshop Manual '282020 Removing and installing ignition coils (V6 Turbo)' or  Workshop Manual
'282020 Removing and installing ignition coils (V8 biturbo)' and repeat the test drive.

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Result of check

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Action required

( )

The fault still occurs on the adjacent
cylinder.

End of check.
Install new spark plug on the adjacent cylinder,
see  Workshop Manual '287020 Removing and
installing spark plugs'.

(✗)

The fault now occurs again on the
original cylinder.

End of check.
Install new ignition coil on the original cylinder,
see  Workshop Manual '282020 Removing and
installing ignition coils (V6 Turbo)' or  Workshop
Manual '282020 Removing and installing ignition
coils (V8 biturbo)'.

Required parts and materials - depending on the result of the check
Parts Info:

Parts required for V6 monoturbo and V6 biturbo engines:
Part No.

Designation

Qty.

Only if fuel injector is replaced:
PAB906036

 High-pressure injector

1 ea.

Only if ignition coil is replaced:
PAC905110A

 Ignition coil with spark plug connector

1 ea.

Only if spark plug is replaced:
9A790560150

 Spark plug

1 ea.

Parts required for V8 biturbo engines:
Part No.

Designation
– Use

Qty.

Only if fuel injector is replaced:
PAC906036H

 High-pressure injector

1 ea.

Only for left cylinder bank:
9A712750700

 Pressure line
– left

1 ea.

Only for right cylinder bank:
9A712750710

 Pressure line
– right

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PAB25372500

 Clamp
– Primary catalytic converter, right

1 ea.

9A725311500

 Seal
– Primary catalytic converter, right

1 ea.

PAB25311500

 Seal
– Primary catalytic converter, right

1 ea.

PAF911308

 Hexagon nuts, self-locking, M8
– Primary catalytic converter, right

3 ea.

N 90335004

 Clamping washers
– Damping for plenum panel

6 ea.

PAF00072900

 Hexagon socket head bolt, M8 x 20
– Front underbody panelling

3 ea.

PAF82595100

 Screw, M6 x 20
– Center underbody panelling, right

1 ea.

9A700768900

 O-ring
– Turbocharger

6 ea.

9A700875500

 O-ring
– Turbocharger

1 ea.

9A700653700

 O-ring
– Turbocharger

2 ea.

N 90925002

 O-ring
– Turbocharger

1 ea.

N 90925001

 O-ring
– Turbocharger

1 ea.

95813302610

 Seal
– Intake pipe

1 ea.

Only if ignition coil is replaced:
PAC905110A

 Ignition coil with spark plug connector

1 ea.

Only if spark plug is replaced:
9A790560150

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 Spark plug

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Materials:

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Required materials (usually already available at the Porsche dealer):
Part No.
00004321083

Designation
– Use
 Lubricant for ignition coil
– Ignition coil

Qty.
20 gram/ 0.7 oz tube

1)

Only if fuel injector is replaced:
00004320935

 Special lubricant for fuel lines
– Fuel lines

1) approx.

1 gram/ 0.035 oz required per vehicle

2) approx.

0.1 liter/ 3.38 fl oz required per vehicle

400 ml/ 13.5 fl oz
spray can 2)

Invoicing
For documentation and warranty invoicing, enter the PQIS coding and parts specified below in the
warranty claim, depending on the time and effort involved:
Location (FES5)

2440A

Injector

Damage type (SA4)

1613

does not function at times

The labor operations must be selected using the Labor Operation List for the work that was carried out.
References

 Workshop Manual '287020 Removing and installing spark plugs'
 Workshop Manual '244019 Removing and installing fuel injector'
 Workshop Manual '282020 Removing and installing ignition coils (V6 Turbo)'
 Workshop Manual '282020 Removing and installing ignition coils (V8 biturbo)'

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.

© 2021 Porsche Cars North America, Inc.

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