No. 174-23

Service
Technical Information
174/23 ENU
8734
8
Little or No Cooling Power from the Air-Conditioning System: Checking Refrigerant Lines
on Air-Conditioning Compressor (174/23)
Model Line:
Panamera (971)
Cayenne (9YA / 9YB)
Model Year:
As of 2019 up to 2024
Equipment:
Without alternative drive system (M-No. 0K0)
Concerns:
Air-conditioning compressor
Information:
Customers complain that the air-conditioning system cooling performance is too low. Drop
formation of refrigerant compressor oil is detected at the low point of the air-conditioning
compressor housing.  Drop formation on air-conditioning compressor
Drop formation on air-conditioning compressor
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Nov 29, 2023
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Service
8734
Technical Information
ENU 174/23
Insufficient sealing of the refrigerant lines on the air-conditioning compressor can lead to a leak in the air-conditioning system.
This leak can be caused by a twisted O-ring  Twisted
O-ring installed in conjunction with the design-related burr
on the O-ring  Twisted O-ring -1- or by a damaged O-ring
on the refrigerant line.
As a result, refrigerant compressor oil can leak and collect
at the flange of the refrigerant line and at the lowest point
of the air-conditioning compressor.
Cause:
Twisted O-ring
Action:
If there is a complaint, check the respective O-ring of the affected refrigerant line and replace it if
necessary.
Installation
Position:
Installation location for air-conditioning compressor / refrigerant lines (shown on the Porsche Cayenne)
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Service
Technical Information
174/23 ENU
8734
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Required parts and materials
Parts Info:
Part No.
Designation
– Location
Number
N 10414402
 Cheese head bolt with multiple-tooth head M8 x 28
– Refrigerant line to compressor
1 piece
95557374903
 O-ring, 23.8 x 2.4
– Refrigerant line between compressor and evaporator
1 piece
or
Only for Panamera (971)
99970755741
 O-ring 11.00 x 2.50 NX
– Refrigerant line between compressor and condenser
1 piece
or
Only for Cayenne (9YA / 9YB)
95557374901
 O-ring, 11,0 x 2.5
– Refrigerant line between compressor and condenser
1 piece
Additional parts required for Cayenne (9YA / 9YB) with Porsche Dynamic Chassis Control
(PDCC) (M-No. 1P7)
PAF00072900
 Hexagon socket head bolt, M8 x 20
– Front section of front underbody cover
3 pieces
or
Additional parts required for Cayenne (9YA / 9YB) with engine protective plate (M-No. 1SF)
N 10082912
 Hexagon screw (instrument cluster), self-locking
M6 x 16
– Front engine protection on holder
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3 pieces
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Service
Materials:
Technical Information
ENU 174/23
8734
Required materials (usually already available in the Porsche Center)
Part No.
Designation
– Location
Quantity
Vehicles with refrigerant R1234yf
9A757390010
 Refrigerant compressor oil 1234yf
– Air-conditioning system
As required
....
 Refrigerant 1234yf
– Air-conditioning system
As required
Vehicles with refrigerant R134a
00004330579
 Refrigerant compressor oil R134a
– Air-conditioning system
As required
....
 Refrigerant R134a
– Air-conditioning system
As required
Required tools
Tools:
•
•
•
•
•
•
Torque wrench, 2-10 Nm (1.5-7.5 ftlb.), e.g., V.A.G 1783 - Torque wrench, 2-10 Nm (1.5-7.5
ftlb.)
Torque wrench, 20-100 Nm (15-74 ftlb.), e.g., VAS 5820 - Torque wrench, 20-100 Nm (15-74
ftlb.)
Air conditioning service unit for R1234yf, e.g., VAS 581 001A - air-conditioning service unit
R1234yf or air conditioning service unit for R134a, e.g., VAS 6746A - air-conditioning service
station R134a
VAS 6122 - Engine plug set
P90999 - PIWIS Tester 4
Battery charger with a current rating of at least 90 A, e.g., VAS 5908 - battery charger 90 A
Checking refrigerant compressor oil loss
Work Procedure: 1
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Remove front underbody cover.
 Workshop Manual '519219 Removing and installing cover for front underbody cover'
2
Remove front left wheel housing liner.
For procedure, see:  Workshop Manual '505619 Removing and installing wheel housing liner front'
3
Check and evaluate refrigerant compressor oil loss on the flange of the refrigerant line for the
compressor - evaporator and refrigerant line for the compressor - condenser on the air-conditioning
compressor.  Oil loss on air-conditioning compressor
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Service
Technical Information
174/23 ENU
8734
8
Oil loss on air-conditioning compressor
Assessment
( )
(✗)
Action
No refrigerant compressor oil loss can be
detected on flange  Oil loss on air-conditioning compressor -1- or air-conditioning
compressor  Oil loss on air-conditioning
compressor -2-.
Locate the complaint elsewhere.
Refrigerant compressor oil loss can be
detected on flange  Oil loss on air-conditioning compressor -1- or air-conditioning
compressor  Oil loss on air-conditioning
compressor -2-.  Flange refrigerant line
leak
Replace the O-ring of the affected refrigerant
line.
End of test.
Continue with:
 Technical Information '505619 Follow-up
actions'
Continue with:
 Technical Information '505619 Replacing
O-ring refrigerant line on air-conditioning
compressor'
Flange refrigerant line leak
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Nov 29, 2023
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Service
Technical Information
ENU 174/23
8734
Replacing O-ring refrigerant line on air-conditioning compressor
Work Procedure: 1
Replace the O-ring of the affected refrigerant line on the air-conditioning compressor.
For procedure, see:
 Workshop Manual '874319 Removing and installing refrigerant line between compressor and
condenser'
 Workshop Manual '874519 Removing and installing compressor/evaporator line (section from
air-conditioning compressor to internal heat exchanger)'
Follow-up actions
Work Procedure: 1
2
Install the front left wheel housing liner.
For procedure, see:  Workshop Manual '505619 Removing and installing wheel housing liner front'
Install front underbody panelling.
 Workshop Manual '519219 Removing and installing cover for front underbody cover'
Working position and PCSS encryption (Panamera)
Labor position:
I No.
APOS
Labor operation
87450100
Checking refrigerant compressor oil loss
87454910
Replacing O-ring refrigerant line on air-conditioning compressor
PCSS encryption:
Location (FES5)
87340
Air-conditioning compressor
Damage type (SA4)
5000
Leaks
Working position and PCSS encryption (Cayenne)
Labor position:
I No.
APOS
Labor operation
87450100
Checking refrigerant compressor oil loss
87454900
Replacing O-ring refrigerant line on air-conditioning compressor
PCSS encryption:
Location (FES5)
87340
Air-conditioning compressor
Damage type (SA4)
5000
Leaks
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Service
Technical Information
174/23 ENU
8734
8
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.
© 2023 Porsche Cars North America, Inc.
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