Audi Q7 2007 Operating instructions

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Repair Manual
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning
Engine ID BAR BHK CAT
A
CNR
B
CJW
C
CJW
B
CJW
E
CTW
A
CTW
B
Edition 04.2013
Service
Service Department. Technical Information

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
List of Workshop Manual Repair Groups
Repair Group
80 - Heating, Ventilation
87 - Air Conditioning
Technical information should always be available to the foremen and mechanics, because their
careful and constant adherence to the instructions is essential to ensure vehicle road-worthiness and
safety. In addition, the normal basic safety precautions for working on motor vehicles must, as a
matter of course, be observed.
Service
All rights reserved.
No reproduction without prior agreement from publisher.
Copyright © 2016 Audi AG, Ingolstadt D3E8002249C

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Contents
80 - Heating, Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Heater, Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
87 - Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1 A/C and Refrigerant Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Safety Precautions for Vehicles with Start/Stop System . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Refrigerant Circuit, Draining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5 Working on the Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 Painting on Vehicles with Air Conditioning System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.7 Further information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 General Repair Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Information for Vehicles with and without Parking/Auxiliary Heater (if Heat Output is Poor)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 OBD and A/C System, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4 Information for Vehicles with Start/Stop System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Component Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3 High Pressure Sensor G65 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.4 High Pressure Sensor G65 , Checking Pressure Signal . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.5 Refrigerant Temperature Sensor G454 Function and Signal Utilization . . . . . . . . . . . . . . 23
3.6 Refrigerant Circuit O-Ring Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.7 Compressor on Bracket, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.8 A/C Compressor Regulator Valve N280 , Checking Activation Signal . . . . . . . . . . . . . . . . 30
4 Compressor Pulley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.2 A/C Compressor Belt Pulley, Overview, Version “1” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.3 Belt Pulley, Removing and Installing at Compressor, Version “1” . . . . . . . . . . . . . . . . . . . . 37
4.4 A/C Compressor Belt Pulley, Overview, Version “2” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.5 Belt Pulley, Removing and Installing at Compressor, Version “2” . . . . . . . . . . . . . . . . . . . . 42
4.6 A/C Compressor Belt Pulley Overview, Version “3” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.7 Belt Pulley on A/C Compressor, Removing and Installing, Version “3” . . . . . . . . . . . . . . . . 45
5 A/C System Control and Regulation Components Outside Passenger Compartment . . . . 48
5.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
5.2 A/C System Components Not Inside Passenger Compartment . . . . . . . . . . . . . . . . . . . . . . 49
5.3 A/C System Fresh Air Intake Shaft, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . 55
5.4 Air Quality Sensor G238 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.5 Air Quality Sensor G238 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
5.6 Air Quality Sensor G238 , Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.7 Vent Frame, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.8 Plenum Chamber Water Drain, Checking and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . 64
6 Incorporation of the A/C System in Vehicle Coolant Circuit . . . . . . . . . . . . . . . . . . . . . . . . 66
6.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
6.2 Incorporation on Vehicles Without Fuel-Driven Auxiliary Heater . . . . . . . . . . . . . . . . . . . . 67
6.3 Incorporation on Vehicles With Fuel-Driven Auxiliary Heater . . . . . . . . . . . . . . . . . . . . . . . . 70
6.4 Coolant Recirculation Pump V50 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . 72
6.5 Coolant Shut-Off Valve N82 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
7 Coolant Circuit, Bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
7.1 A/C System Coolant Circuit Section, Bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
Contents i

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
8 Components Actuated by A/C System, Electrical Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.2 Rear Window Defogger Z1 , Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.3 Heated Seats and Seat Ventilation, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.4 Auxiliary Heater Heating Element Z35 , Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
8.5 Testing the Fuel-Driven Auxiliary Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
9 A/C System Control Components Inside Passenger Compartment . . . . . . . . . . . . . . . . . . 92
9.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
9.2 Front A/C System Components in Passenger Compartment (Illustration of Left Side) . . . . 96
9.3 Sunlight Photo Sensor G107 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . 103
9.4 Interior Temperature Sensor Fan V42 , Removing and Installing . . . . . . . . . . . . . . . . . . . . 104
9.5 Climatronic Control Module J255 Front A/C Control Head Information, Removing and
Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
9.6 Left Footwell Vent Temperature Sensor G261 , Removing and Installing . . . . . . . . . . . . 111
9.7 Left Footwell Door Motor V108 , Removing and Installing, “Comfort” Version . . . . . . . . . . 112
9.8 Left Temperature Door Motor V158 , Removing and Installing, “Comfort” Version . . . . . . 113
9.9 Retaining plate with Left Footwell Door Motor V108 and Left Temperature Door Motor V158 ,
Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
9.10 Left Heater Core Covers, Removing and Installing, Front A/C Unit Installed . . . . . . . . . . . . 117
9.11 Preparing Adapter Cables for Control Motor Actuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
9.12 Defroster Door Motor V107 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
9.13 Left Center Vent Motor V110 , Removing and Installing, “Comfort” Version Only . . . . . . 121
9.14 Left Side Vent Motor V299 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
9.15 Retaining plate with Defroster Door Motor V107 , Left Side Vent Motor V299 (and Left Center
Vent Motor V110 ), Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
9.16 Left Front Upper Body Vent Temperature Sensor G385 , Removing and Installing . . . . . . 131
9.17 Indirect Ventilation Door Motor V213 , Removing and Installing . . . . . . . . . . . . . . . . . . . . 132
9.18 Front Heater Core, Removing and Installing, A/C Unit Installed . . . . . . . . . . . . . . . . . . . . 134
9.19 Auxiliary Heater Heating Element Z35 , Removing and Installing . . . . . . . . . . . . . . . . . . . . 140
9.20 Front A/C System Components in Passenger Compartment (Illustration of Right Side) . . 144
9.21 Right Temperature Door Motor V159 (or Left Temperature Door Motor V158 ), Removing and
Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
9.22 Right Footwell Door Motor V109 (or Left Footwell Door Motor V108 ), Removing and
Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
9.23 Retaining Plate with Control Motors V158 ( V159 ) and V109 ( V108 ), Removing and
Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
9.24 Right Heater Core Covers, Removing and Installing, Front A/C Unit Installed . . . . . . . . . . 156
9.25 Right Center Vent Motor V111 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . 156
9.26 Right Side Vent Motor V300 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
9.27 Retaining Plate with Control Motors V111 and V300 , Removing and Installing . . . . . . . . 158
9.28 Right Front Upper Body Vent Temperature Sensor G386 , Removing and Installing . . . . 161
9.29 Evaporator Vent Temperature Sensor G263 , Removing and Installing . . . . . . . . . . . . . . 162
9.30 Fresh Air Blower V2 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
9.31 Fresh Air Blower Control Module J126 , Removing and Installing . . . . . . . . . . . . . . . . . . . . 164
9.32 Recirculation Door Motor V113 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . 166
9.33 Fresh Air Intake Duct Temperature Sensor G89 , Removing and Installing . . . . . . . . . . . . 167
9.34 Right Footwell Vent Temperature Sensor G262 , Removing and Installing . . . . . . . . . . . . 168
9.35 Dust and Pollen Filter, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
9.36 Dust and Pollen Filter with Activated Charcoal Filter Unit . . . . . . . . . . . . . . . . . . . . . . . . . . 170
9.37 Front Condensation Water Drain Hose, Checking, Removing and Installing . . . . . . . . . . . . 171
9.38 Rear A/C System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
9.39 Rear A/C Unit, Bringing into Service Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
9.40 Heater Core, Removing and Installing, Rear A/C Unit Installed . . . . . . . . . . . . . . . . . . . . . . 182
9.41 Rear Fresh Air Blower V80 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
9.42 Rear Fresh Air Blower Control Module J391 , Removing and Installing . . . . . . . . . . . . . . 185
9.43 Right Rear Temperature Door Motor V314 , Removing and Installing . . . . . . . . . . . . . . . . 186
9.44 Right Rear Air Door Motor V240 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . 186
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
ii Contents

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
9.45 Left Rear Air Door Motor V239 , Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . 187
9.46 Left Rear Temperature Door Motor V313 , Removing and Installing . . . . . . . . . . . . . . . . . . 188
9.47 Right Rear Vent Temperature Sensor G406 and Left Rear Vent Temperature Sensor G405 ,
Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
9.48 Rear A/C Display Control Head E265 , Removing and Installing . . . . . . . . . . . . . . . . . . . . 190
9.49 Rear Center Console Vents, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
9.50 Left B-Pillar/Footwell Shut-Off Door Motor V212 , Removing and Installing . . . . . . . . . . . . 192
9.51 Left Rear Upper Body Vent Motor V315 , Removing and Installing . . . . . . . . . . . . . . . . . . 192
9.52 Right Rear Upper Body Vent Motor V316 , Removing and Installing . . . . . . . . . . . . . . . . . . 194
9.53 Right B-Pillar/Footwell Shut-Off Door Motor V211 , Removing and Installing . . . . . . . . . . 195
9.54 Rear Condensation Water Drain, Checking, Removing And Installing . . . . . . . . . . . . . . . . 196
10 A/C System Evaporator, Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
10.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
10.2 Causes of Odor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
10.3 Front (and Rear) A/C System Evaporator, Cleaning, Using Ultrasound A/C Cleaner
VAS6189A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
11 Incorporation of Rear A/C Unit into Refrigerant And Coolant Circuit . . . . . . . . . . . . . . . . . . 203
11.1 Incorporation of Rear A/C Unit into Vehicle Refrigerant- and Coolant Circuit . . . . . . . . . . 203
12 Air Ducts in and to Front and Rear A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
12.1 Air Duct to and from Front A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
12.2 Air Duct in Front A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
12.3 Instrument Panel Vents and Air Ducts in Front (and Rear) Passenger Compartment . . . . 209
12.4 Air Duct in Rear A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
12.5 Air Channels and Rear Vents (on Vehicles with Rear A/C Unit) . . . . . . . . . . . . . . . . . . . . 212
13 A/C Unit, Checking Cooling Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
13.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
13.2 Front A/C System, Testing Cooling Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
13.3 Rear A/C System, Testing Cooling Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
14 Heating Performance of A/C System, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
14.1 Coolant Recirculation Pump V50 ( Water Pump V36 ) Functionality, Checking . . . . . . . . 234
15 Refrigerant Circuit, Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
15.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
15.2 Refrigerant Circuit, Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
15.3 Refrigerant Lines, Disconnecting from Compressor and Connecting . . . . . . . . . . . . . . . . 250
15.4 Compressor, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
15.5 Refrigerant Temperature Sensor G454 , Removing and Installing . . . . . . . . . . . . . . . . . . 255
15.6 Refrigerant Lines, Disconnecting from Condenser and Connecting . . . . . . . . . . . . . . . . . . 256
15.7 Condenser, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
15.8 Connection Points of Refrigerant Lines, Loosening and Assembling . . . . . . . . . . . . . . . . 262
15.9 Dryer Cartridge, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
15.10 Front Expansion Valve, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
15.11 Refrigerant Lines from Rear Expansion Valve, Disconnecting and Connecting . . . . . . . . 272
15.12 Rear Expansion Valve, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
16 Compressor, Removing and Installing (Vehicles with 8-Cylinder Engine and 12-Cylinder TDI
Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
16.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
16.2 Compressor, Removing and Installing (Vehicles with 8-Cylinder TDI Engine) . . . . . . . . . . 277
16.3 Compressor, Removing and Installing (Vehicles with 12-Cylinder TDI Engine) . . . . . . . . . . 280
16.4 Compressor, Removing and Installing (Vehicles with 8-Cylinder FSI Engine) . . . . . . . . . . 283
16.5 Compressor Drive Unit, Checking and Replacing (Vehicles with 8-Cylinder FSI Engine) . . 290
16.6 Compressor Input Shaft, Loosening and Tightening (Vehicles with 8-Cylinder FSI Engine)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
16.7 Compressor Input Shaft, Removing and Installing (Vehicles with 8-Cylinder FSI Engine)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
16.8 Drive Plate with Overload Protection, Removing and Installing (Vehicles with 8-Cylinder FSI
Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
Contents iii

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with respect to the correctness of information in this document. Copyright by AUDI AG.
16.9 Drive Plate Run-Out with Overload Protection, Checking and Adjusting (Vehicles with 8-
Cylinder FSI Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
16.10 Drive Plate, Removing from A/C Compressor and Installing (Vehicles with 8-Cylinder FSI
Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
16.11 Drive Plate with Cylindrical Roller Bearing, Removing and Installing (Vehicles with 8-Cylinder
FSI Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
17 Front A/C Unit, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
17.1 Front A/C Unit, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
17.2 Heater Core, Removing and Installing, with Front A/C Unit Removed . . . . . . . . . . . . . . . . 303
17.3 Front A/C Unit Evaporator, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
18 Front A/C Unit, Disassembling and Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
18.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
18.2 Attachments, Removing from Front A/C Unit and Installing . . . . . . . . . . . . . . . . . . . . . . . . 307
18.3 Front A/C Unit, Disassembling and Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
18.4 Front A/C Unit Air Distribution Housing, Disassembling and Assembling . . . . . . . . . . . . . . 316
18.5 Front A/C Unit Evaporator Housing, Disassembling and Assembling . . . . . . . . . . . . . . . . 317
19 Rear A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
19.1 Rear Evaporator, Removing and Installing, A/C Unit Installed . . . . . . . . . . . . . . . . . . . . . . 321
19.2 Coolant Hose and Refrigerant Line Pass-Through to Rear Wheel Housing, Removing and
Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
19.3 Rear A/C Unit, Removing and Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
20 Rear A/C Unit, Disassembling and Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
20.1 Attachments, Removing from Rear A/C Unit and Installing . . . . . . . . . . . . . . . . . . . . . . . . 327
20.2 Rear A/C Unit, Disassembling and Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
21 A/C System, Operating after Filling Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
22 Refrigerant and Refrigerant Oil Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
23 Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
24 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Audi Q7 2007 ➤
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iv Contents

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80 – Heating, Ventilation
1 Heater, Servicing
(Edition 04.2013)
♦ There is only one A/C system offered for vehicles of this series.
Heating without an A/C system is not currently offered.
♦ All information required for servicing the heating and A/C sys‐
tem can be found the A/C system. Refer to
⇒ G r.87 “Air Conditioning”, page 2 .
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
1. Heater, Servicing 1

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87 – Air Conditioning
1 A/C and Refrigerant Safety Precau‐
tions
⇒ “1.1 General Information”, page 2
⇒ “1.2 Safety Precautions”, page 2
⇒ “1.3 Safety Precautions for Vehicles with Start/Stop System”,
page 3
⇒ “1.4 Refrigerant Circuit, Draining”, page 3
⇒ “1.5 Working on the Refrigerant Circuit”, page 4
⇒ “1.6 Painting on Vehicles with Air Conditioning System”,
page 4
⇒ “1.7 Further information”, page 5
1.1 General Information
The assemblies and piping system of the air conditioner are filled
with the following refrigerant:
1.1.1.2 Tetrafluorethane (CF3-CH2F or CH2F-CF3)
Currently, this refrigerant is known under the following trade
names R134a, H-FKW 134a, SUVA 134a and KLEA 134a (other
trade names may be used in other countries).
1.2 Safety Precautions
The following safety measures should be observed for these re‐
frigerants (additional guidelines apply in individual countries).
If is necessary to open the refrigerant circuit during service work,
discharge the refrigerant circuit first. Refer to
⇒ “1.4 Refrigerant Circuit, Draining”, page 3 . In doing so, the
utmost care is to be taken to avoid contact with liquid refrigerant
or refrigerant vapors. Should refrigerant nevertheless escape,
avoid inhaling the resultant refrigerant/air mixture.
Always wear hand and eye protection (gloves and goggles) when
working around the A/C refrigerant system and switch on work‐
shop exhaust/ventilation systems.
Reason:
Intensive exposure to refrigerant on unprotected parts of the body
will result in frostbite.
WARNING
Keep an eye bath on hand.
If liquid refrigerant has come in contact with your skin and eyes,
immediately flush with cool water for 15 minutes.
Then apply eye drops and consult a doctor immediately even
if no pain is felt.
The doctor must be informed, which type of refrigerant caused
the freezing.
Should refrigerant come into contact with other parts of the body
despite compliance with all the pertinent safety measures, these
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
2 Rep. Gr.87 - Air Conditioning

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are similarly to be rinsed thoroughly in cold water without delay
for at least 15 minutes.
Although refrigerant does not represent a fire hazard, smoking,
welding, soldering and brazing are not permitted in areas exposed
to refrigerant.
Reason:
The high temperature of a naked flame or hot objects causes de‐
composition of refrigerant gas. Inhalation of the resultant toxic
decomposition products leads to dry coughing and nausea.
1.3 Safety Precautions for Vehicles with
Start/Stop System
WARNING
On vehicles with the Start/Stop System, the engine could start
automatically and cause serious personal injury.
♦ If the Start/Stop System is activated (recognizable by a
message in the instrument cluster), it is possible to start
the engine automatically.
♦ Make sure the Start/Stop System is deactivated (ignition
switched off) whenever working on the vehicle.
1.4 Refrigerant Circuit, Draining
Refrigerant is never to be allowed to escape into the atmosphere,
but rather it is to be extracted from the refrigerant circuit using an
extractor or service station. The drained refrigerant will be locally
recycled or is send to an environment-recycling place to the man‐
ufacturer (different or additional laws may apply in individual
companies). For this reason, bring the vehicle to a workshop that
has the necessary tools and in which the work can be performed
accordingly by qualified personnel. Refer to ⇒ Refrigerant R134a
Servicing; Rep. Gr. 87 ; A/C System General Information (A/C
System with Refrigerant R134a; A/C System, General Informa‐
tion).
Reason:
If refrigerant R134a is released into the environment, it enhances
the »green house effect«.
Note
♦ Refrigerant R134a has far less of a greenhouse effect than
R12.
♦ Because R-134a does not contain chlorine atoms, the major
catalyst in ozone depletion, R134a has no ozone depletion
potential. Depletion of the ozone layer in the upper atmos‐
phere is however only brought about by the splitting of carbon–
chlorine bonds (as is the case, for example, with refrigerant
R12).
After discharging the A/C system, disconnect the harness con‐
nector from A/C Compressor Regulator Valve - N280- or from the
High Pressure Sensor - G65- .
Reason:
The A/C Compressor Regulator Valve - N280- is then no longer
activated and compressor runs at idle. The compressor is de‐
signed such that lubrication of compressor components is guar‐
Audi Q7 2007 ➤
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1. A/C and Refrigerant Safety Precautions 3

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anteed by way of an internal oil circuit at idle (provided there is
sufficient refrigerant oil in the compressor).
1.5 Working on the Refrigerant Circuit
Work on refrigerant system should only be performed in a venti‐
lated rooms (workshops). Ensure that there are no working-pits,
basement staircases or shafts within five meters of the circum‐
ference. Extraction systems are to be switched on.
Reason:
The refrigerant emerging is not only colorless and odorless, but
also heavier than air and thus displaces oxygen. If refrigerant gas
does escape even though all the safety precautions have been
followed, there is a risk of suffocating in poorly ventilated areas
and in workshop pits - even if it is not noticeable.
Note
The escaping refrigerant/air mixture should not be inhaled, but
should be sucked out via an existing exhaust ventilation system.
Do not attempt repair on filled air conditioning systems by solder‐
ing, brazing or welding. This pertains also for welding and sol‐
dering work on the vehicle, in the event that parts of the climate
control system may heat up
Reason:
Exposure to heat creates considerable pressure in the system,
which could cause it to burst.
Corrective action:
Discharge the refrigerant circuit. Refer to
⇒ “1.4 Refrigerant Circuit, Draining”, page 3 .
Note
Damaged or leaking parts of the air conditioner are never to be
repaired by welding or soldering them; they are always to be re‐
placed.
When servicing air conditioner, all open components and pipe
connections are to be immediately re-sealed.
Reason:
Moisture will ingress into air conditioner components if they are
left open for a lengthy period. An A/C system that was open for a
longer period of time cannot be filled again without replacing
components of the system.
1.6 Painting on Vehicles with Air Condition‐
ing System
When performing paint work repairs, object temperatures of 80°
C are not to be exceeded in drying booths or their pre-heating
areas.
Reason:
Exposure to heat creates considerable pressure in the system,
which could cause it to burst.
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
4 Rep. Gr.87 - Air Conditioning

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1.7 Further information
♦ Use the Vehicle Diagnostic Tester in the “Guided Fault Find‐
ing” function.
♦ The applicable wiring diagrams can be found in Electrical Wir‐
ing Diagrams, Troubleshooting and Component Locations.
Refer to Wiring diagrams, Troubleshooting and Component
locations.
♦ A data plate in engine compartment indicates the refrigerant
used and capacity.
♦ For further information on repairing vehicles equipped with a/
c and handling refrigerants, refer to ⇒ Refrigerant R134a
Servicing; Rep. Gr. 87 ; A/C System General Information (Re‐
frigerant R134a, Servicing; A/C System, General Information).
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
1. A/C and Refrigerant Safety Precautions 5

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2 General Repair Information
⇒ “2.1 General Information”, page 6
⇒ “2.2 Information for Vehicles with and without Parking/Auxiliary
Heater (if Heat Output is Poor)”, page 6
⇒ “2.3 OBD and A/C System, Checking”, page 9
⇒ “2.4 Information for Vehicles with Start/Stop System ”,
page 10
2.1 General Information
DANGER!
Before working on electrical system (wiring), remove relevant
fuse(s).
Note
Before performing electric welding on the vehicle, disconnect the
battery. ⇒ Electrical Equipment; Rep. Gr. 27 ; Battery; Battery,
Disconnecting and Connecting
Refrigerant circuit of A/C system must not be discharged and
opened (refer to ⇒ “1.4 Refrigerant Circuit, Draining”, page 3 )
unless this is necessary because of safety precautions (refer to
⇒ “1 A/C and Refrigerant Safety Precautions”, page 2 ) or unless
components of the refrigerant circuit of the A/C system have to
be to replaced.
The air conditioner refrigerant circuit is not to be opened when
performing all other standard vehicle repair operations.
Servicing operations that can be performed on the heating and
air conditioning system without opening the refrigerant circuit are
described in this repair manual. Refer to
⇒ “3 Refrigerant Circuit”, page 12 .
Note
The connections for the sensors/switches mentioned in this repair
manual are not always equipped with a valve. Valve closes au‐
tomatically when unscrewing the switch, therefore only switches
on which the connection is equipped with a valve maybe replaced
when the refrigerant circuit is charged.
This repair manual also describes service procedures that require
the refrigerant circuit to be emptied, even though they cannot be
performed in every workshop (refer to
⇒ “15 Refrigerant Circuit, Servicing”, page 241 ) (to drain the re‐
frigerant circuit, bring the vehicle to a workshop that has the
necessary tools and qualified personnel. Refer to ⇒ Refrigerant
R134a Servicing; Rep. Gr. 87 ; A/C System General Informa‐
tion .).
2.2 Information for Vehicles with and with‐
out Parking/Auxiliary Heater (if Heat
Output is Poor)
♦ If a customer complains that the their gasoline vehicle without
an auxiliary heater has poor heating, check the heating per‐
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
6 Rep. Gr.87 - Air Conditioning

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formance of the A/C system as well as the function of the
Coolant Recirculation Pump - V50- (as well as on vehicles with
a 6-cylinder FSI engine Water Pump - V36- ). Refer to
⇒ “14 Heating Performance of A/C System, Checking”,
page 231 . Use the Vehicle Diagnostic Tester via the “Guided
Fault Finding” function
♦ If the vehicle has a diesel engine and a fuel driven auxiliary
heater (and without the auxiliary heater option) and there is a
complaint that there is poor or insufficient heating, check the
incorporation of the auxiliary heater into the coolant circuit as
well as the auxiliary heater control and function (controlled by
the Auxiliary Heater Control Module - J364- ).. Use the Vehicle
Diagnostic Tester via the “Guided Fault Finding” function.
♦ If poor or insufficient heating performance (for example, at low
engine speeds) is reported on gasoline or diesel vehicles with
a parking/auxiliary heater installed as optional equipment,
check the activation of the Coolant Recirculation Pump - V50-
(also the Water Pump - V36- on vehicles with 6-cylinder FSI
engine), Heater Coolant Shut-Off Valve - N279- , incorporation
of parking/auxiliary heater into the coolant circuit, as well as
the activation and functionality of the parking/auxiliary heater
(activation of Auxiliary Heater Control Module - J364- ). Refer
to ⇒ Parking/Auxiliary Heater; Rep. Gr. 82 . Use the Vehicle
Diagnostic Tester via the “Guided Fault Finding” function.
♦ If there is poor and insufficient heating on vehicles with a diesel
engine but without a fuel driven auxiliary heater (with an Aux‐
iliary Heater Heating Element - Z35- ), check the activation and
the functionality of the -Z35- (and the Heater Coolant Shut-Off
Valve - N279- on vehicles from MY 2011, if applicable). Refer
to
⇒ “8.4 Auxiliary Heater Heating Element Z35 , Checking”,
page 85 . Use the Vehicle Diagnostic Tester via the “Guided
Fault Finding” function
Audi Q7 2007 ➤
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2. General Repair Information 7

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Note
♦ By activation of the Coolant Recirculation Pump - V50- (also
the Water Pump - V36- on vehicles with a 6 cylinder FSI en‐
gine), the coolant flow through the A/C system heater core(s)
is increased at low engine speeds, thus achieving better heat‐
ing performance.
♦ The Coolant Recirculation Pump - V50- (or the Water Pump -
V36- ) is switched on by the Climatronic Control Module - J255-
front A/C control head as soon as all switched-on conditions
are met (the ignition is switched on, the Climatronic Control
Module - J255- front A/C control head is switched on, the
OFF button is not activated, etc.). Refer to
⇒ “14 Heating Performance of A/C System, Checking”,
page 231 .
♦ The Climatronic Control Module - J255- front A/C control head
also turns on the Coolant Recirculation Pump - V50- (also the
Water Pump - V36- on vehicles with a 6 cylinder FSI engine),
if it receives certain information via the Comfort CAN-Bus sys‐
tem from the Auxiliary Heater Control Module - J364- . Refer
to ⇒ Parking/Auxiliary Heater; Rep. Gr. 82 . Use the Vehicle
Diagnostic Tester via the “Guided Fault Finding” function.
♦ Incorporation of parking/auxiliary heater (and of Coolant Re‐
circulation Pump - V50- and of Water Pump - V36- ) into the
coolant circuit.
♦ From MY 2009, certain vehicles with a 6-cylinder TDI engine
without an “auxiliary heater”, have an Auxiliary Heater Heating
Element - Z35- instead of a fuel-driven auxiliary heater instal‐
led depending on the emissions standard (running change
depending on the engine). Refer to the ⇒ Audi Sales Program ,
⇒ “8.4 Auxiliary Heater Heating Element Z35 , Checking”,
page 85 . Auxiliary Heater Heating Element - Z35- . For re‐
moving and installing, refer to
⇒ “9.19 Auxiliary Heater Heating Element Z35 , Removing and
Installing”, page 140 ; for checking, refer to
⇒ “8.4 Auxiliary Heater Heating Element Z35 , Checking”,
page 85 .
♦ From MY 2011, this vehicle has a Start/Stop System for spe‐
cific engines as optional equipment. On vehicles with a Start/
Stop system, the Coolant Recirculation Pump - V50- is turned
on by the climatronic control module -J255- during the stop
function when it is necessary to heat the passenger compart‐
ment. In the case of poor heating output when the Stop Func‐
tion is active on these vehicles, check the coolant recirculation
pump -V50- functionality. Use the Vehicle Diagnostic Tester
via the “Guided Fault Finding” function.
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
8 Rep. Gr.87 - Air Conditioning

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♦ On vehicles from MY 2011 with a diesel engine and with the
start/stop system without the optional “auxiliary heater” (with
a fuel-driven auxiliary heater or an Auxiliary Heater Heating
Element - Z35- ), a Heater Coolant Shut-Off Valve - Z35- may
be installed in addition. In the case that the heating output on
these vehicles is lacking, additionally check the actuation and
functionality of the heater coolant shut-off valve -N279- . (For
the installed location, refer to ⇒ Heating, Ventilation and Air
Conditioning; Rep. Gr. 82 , Incorporation into the Vehicle
Electronics and Activation of the Heater Coolant Shut-Off
Valve -N279- . Refer to Wiring diagrams, Troubleshooting and
Component locations). For vehicles with an auxiliary heater
heating element -Z35- , the heater coolant shut-off valve -
N279- is activated via a relay (for example, via the Engine
Coolant Shut-Off Valve Relay - J541- ) from the Climatronic
Control Module - J255- front A/C control head. Refer to Wiring
diagrams, Troubleshooting and Component locations. Use the
Vehicle Diagnostic Tester via the “Guided Fault Finding” func‐
tion.
♦ From MY 2014, a Coolant Shut-Off Valve - N82- is installed on
certain engines without the optional “parking heater”. The
coolant shut-off valve -N82- is activated by the Climatronic
Control Module - J255- front A/C control head (via the Engine
Coolant Shut-Off Valve Relay - J541- ), when no heat is de‐
sired in the passenger compartment. Refer to
⇒ “6.5 Coolant Shut-Off Valve N82 , Removing and Installing”,
page 75 and Wiring diagrams, Troubleshooting and Com‐
ponent locations. The Heater Coolant Shut-Off Valve - N279-
is activated by the Auxiliary Heater Control Module - J364-
when requested by the Climatronic Control Module - J255- on
vehicles with the optional “parking heater” and a motor on
which a coolant shut-off valve -N82- would be activated (ob‐
serve the parking heater adaptation). Use the Vehicle Diag‐
nostic Tester via the “Guided Fault Finding” function.
2.3 OBD and A/C System, Checking
♦ The function “electrical testing” is not described in this Repair
Manual. Perform electrical testing via “Guided Fault Finding”
function, here can also be found notes on the functions which
should be tested. Use the Vehicle Diagnostic Tester via the
“Guided Fault Finding” function.
♦ Temperature-dependent resistance values of the various tem‐
perature sensors are stored in one table, these can be called
up via the “Guided Fault Finding” function. Use the Vehicle
Diagnostic Tester via the “Guided Fault Finding” function.
♦ Climatronic Control Module - J255- and Rear A/C Display
Control Head - E265- are available in different versions. Pay
attention to precise assignment on replacement. Refer to the
Parts Catalog.
♦ The A/C system OBD is performed in the “Guided Fault Find‐
ing” function with the Vehicle Diagnostic Tester. Use the Ve‐
hicle Diagnostic Tester via the “Guided Fault Finding” function.
♦ The Climatronic Control Module - J255- “Comfort” version
cannot always be exchanged in the familiar way, as soon as
Climatronic Control Module - J255- “Comfort” version has
been adapted once in a vehicle, the component protection
takes effect. This function is currently not on the “Basis” ver‐
sion). The component protection can only be canceled by
entering specific vehicle data. Use the Vehicle Diagnostic
Tester via the “Guided Fault Finding” function.
♦ If a Climatronic control module is installed on the “Comfort”
front A/C control head with active component protection is in‐
stalled in a different vehicle, only the functions necessary for
vehicle safety can be selected. Comfort functions can no lon‐
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
2. General Repair Information 9

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ger be selected. Use the Vehicle Diagnostic Tester via the
“Guided Fault Finding” function.
♦ If a Climatronic Control Module - J255- front A/C control head
(or Rear A/C Display Control Head - E265- ) is to be replaced,
check the coding ( Climatronic Control Module - J255- front A/
C control head) and adaptation (front Climatronic Control Mod‐
ule - J255- and Rear A/C Display Control Head - E265- ) before
removing with the “Replace control module” function of Guided
Fault Finding for this control head. Use the Vehicle Diagnostic
Tester via the “Guided Fault Finding” function.
♦ On vehicles equipped with rear A/C system, the DTC “Check
DTC memory of Climatronic Control Module” is entered in
Rear A/C Display Control Head - E265- for certain malfunc‐
tions at the front A/C system. After erasing the DTC memory,
check the Climatronic Control Module - J255- and the DTC
memory of the Rear A/C Display Control Head - E265- . Use
the Vehicle Diagnostic Tester via the “Guided Fault Finding”
function.
♦ Pressing and holding the buttons on the Climatronic Control
Module - J255- front A/C control head or Rear A/C Display
Control Head - E265- for an extended period of time (for ex‐
ample, setting an object down on them) can cause an entry in
the DTC memory due to stuck buttons. If necessary, check the
function of the buttons and erase the DTC memory if no mal‐
function is found.
♦ Certain malfunctions can be erased only after starting engine
(for example, “ignition off time period signal” after replacing
Instrument Cluster Control Module - J285- ). If a malfunction
cannot be erased, start engine and let it run for one minute
before checking and erasing DTC memory again.
♦ The Refrigerant Temperature Sensor - G454- was discontin‐
ued from 11/2007 as a running change. On vehicles with the
“Comfort” A/C system, make sure the Climatronic Control
Module - J255- for the “Comfort” A/C system is installed. Ve‐
hicles with a 6-cylinder TDI engine, an 8-cylinder engine or a
12-cylinder TDI engine but without a Refrigerant Temperature
Sensor - G454- may only have the “Comfort” front control and
display unit installed (part number “4L0 820 043”, beginning
with index letter “K”). Refer to the Parts Catalog.
♦ If the vehicle has the “Basis” A/C system without a Refrigerant
Temperature Sensor - G454- , and the sensor -G454- is being
displayed as a fault, then perform an adaptation to the “Basis”
front A/C control head. It is not necessary to perform this on
the “Comfort” A/C system because it has different versions of
the front A/C control head. On vehicles wit the “Basis” A/C
system, “Guided Fault Finding” displays the fault missing Re‐
frigerant Temperature Sensor - G454- and the evaluating of
the refrigerant temperature sensor -G454- switches off (by en‐
tering “adaptation”). Use the Vehicle Diagnostic Tester via the
“Guided Fault Finding” function.
♦ From 11/2007, the “Comfort” A/C system as an updated Fresh
Air Blower Control Module - J126- (an updated “Comfort” Cli‐
matronic Control Module - J255- and an updated Fresh Air
Blower - V2- ). An updated air intake housing is also being
used. Make sure to use the correct allocation for these parts
with each other. Refer to
⇒ “9.31 Fresh Air Blower Control Module J126 , Removing
and Installing”, page 164 and to the Parts Catalog.
2.4 Information for Vehicles with Start/Stop
System
♦ From MY 2011, this vehicle has a Start/Stop System for spe‐
cific engines as optional equipment. Pay attention to the cor‐
rect version, coding and adapting for the Climatronic Control
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
10 Rep. Gr.87 - Air Conditioning

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Module - J255- front A/C control head on these vehicles. Refer
to the Parts Catalog. Use the Vehicle Diagnostic Tester via the
“Guided Fault Finding” function.
♦ On a vehicle with a start/stop system and a parking-/auxiliary
heater, pay attention to the correct version, coding and adapt‐
ing of the parking-/auxiliary heater (for the Auxiliary Heater
Control Module - J364- ). Refer to the Parts Catalog. Use the
Vehicle Diagnostic Tester via the “Guided Fault Finding” func‐
tion.
♦ On vehicles with the start/stop system, the activation of certain
vehicle systems (e.g. rear window defogging, seat heater and
ventilation, the Auxiliary Heater Heating Element - Z35- , etc.)
may be turned off while the stop function is active (to protect
the Battery - A- ). The setting for activating this system remains
stored however in the Climatronic Control Module - J255- front
A/C control head. After the engine is restarted via the start
function, these will also be turned on again. Use the Vehicle
Diagnostic Tester via the “Guided Fault Finding” function. Use
the Vehicle Diagnostic Tester via the “Guided Fault Finding”
function.
♦ On vehicles with a start/stop system, the Coolant Recirculation
Pump - V50- is turned on by the climatronic control module -
J255- during the stop function when more heating output is
required in the passenger compartment. Use the Vehicle Di‐
agnostic Tester via the “Guided Fault Finding” function.
♦ A Humidity Sensor - G355- is also installed in the base of the
mirror on the windshield on vehicles with a start/stop system.
Refer to ⇒ Body Exterior; Rep. Gr. 68 ; Interior Rearview
Mirror; Interior Rearview Mirror, General Information . The sig‐
nal from the Humidity Sensor - G355- (only installed on vehi‐
cles with the start/stop system) is evaluated directly by the
Climatronic Control Module - J255- front A/C control head. The
measured values for the humidity sensor -G355- are then di‐
rectly transferred to the climatronic control module -J255- via
a local data bus. Therefore make sure that the version, coding
and adaptation for the climatronic control module -J255- and
for the comfort system central control module -J393- are cor‐
rect. Refer to the Parts Catalog. Use the Vehicle Diagnostic
Tester via the “Guided Fault Finding” function. If the clima‐
tronic control module -J255- detects a possible warning based
on the measured values from the humidity sensor -G355- ,
such as the humidity is too high in the passanger compartment
causing the windows to fog up, the climatronic control module
-J255- prevents the stop function from activating or interrupts
an already active stop function and starts the engine. Use the
Vehicle Diagnostic Tester via the “Guided Fault Finding” func‐
tion.
♦ On vehicles from MY 2011 with a diesel engine and with the
start/stop system without the optional “auxiliary heater” (with
a fuel-driven auxiliary heater or an Auxiliary Heater Heating
Element - Z35- ), a Heater Coolant Shut-Off Valve - N279- may
be installed in addition. In the case that the heating output on
these vehicles is lacking, additionally check the actuation and
functionality of the heater coolant shut-off valve -N279- ., In‐
corporation into the Vehicle Electronics and Activation of the
Heater Coolant Shut-Off Valve -N279- . Refer to Wiring dia‐
grams, Troubleshooting and Component locations). For vehi‐
cles with an auxiliary heater heating element -Z35- , the heater
coolant shut-off valve -N279- is activated via a relay (for ex‐
ample, via the Engine Coolant Shut-Off Valve Relay - J541- )
from the Climatronic Control Module - J255- front A/C control
head. Refer to Wiring diagrams, Troubleshooting and Com‐
ponent locations. Use the Vehicle Diagnostic Tester via the
“Guided Fault Finding” function.
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
2. General Repair Information 11

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
3 Refrigerant Circuit
⇒ “3.1 General Information”, page 12
⇒ “3.2 Component Overview”, page 12
⇒ “3.3 High Pressure Sensor G65 , Removing and Installing”,
page 18
⇒ “3.4 High Pressure Sensor G65 , Checking Pressure Signal”,
page 19
⇒ “3.5 Refrigerant Temperature Sensor G454 Function and Sig‐
nal Utilization”, page 23
⇒ “3.6 Refrigerant Circuit O-Ring Seals”, page 26
⇒ “3.7 Compressor on Bracket, Removing and Installing”,
page 27
⇒ “3.8 A/C Compressor Regulator Valve N280 , Checking Acti‐
vation Signal”, page 30
3.1 General Information
Note
♦ Refrigerant circuit, servicing. Refer to
⇒ “15 Refrigerant Circuit, Servicing”, page 241 .
♦
All work or components marked with 1) can be repaired, re‐
placed or performed in any workshop (work that does not
pertain to refrigerant circuit).
♦
All refrigerant circuit components not marked with
1) as well as
all refrigerant hoses and lines can only be repaired or replaced
in a workshop equipped with the necessary tools and where
the procedures are performed by qualified personnel (the re‐
frigerant circuit must be discharged). Refer to ⇒ Refrigerant
R134a Servicing; Rep. Gr. 87 ; A/C System General Informa‐
tion (A/C System with Refrigerant R134a; A/C System, Gen‐
eral Information).
3.2 Component Overview
Note
This illustration shows in one overview the various refrigerant cir‐
cuit components, the exact arrangement inside the vehicle de‐
pends on version and engine.
HD = High-pressure end
ND = Low-pressure end
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
12 Rep. Gr.87 - Air Conditioning

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
1 - A/C Compressor Regulator
Valve - N280-
❑ Checking activation and
function. Refer to
⇒ “3.8 A/C Compressor
Regulator Valve N280 ,
Checking Activation
Signal”, page 30 1) .
Note
♦ Certain functions on the A/C
compressor regulator valve -
N280- (for example, a stuck
valve or a disruption in the coil)
can lead to a complaint regard‐
ing the A/C compressor (A/C
system doesn't cool, the evapo‐
rator ices over, etc.). If the cause
is with the A/C compressor reg‐
ulator valve -N280- (and not the
A/C compressor itself), the A/C
compressor can be serviced by
replacing the valve -N280- . Re‐
fer to ⇒ Refrigerant R134a Serv‐
icing; Rep. Gr. 87 ; A/C System
General Information (Refrigerant
R134a, Servicing; Refrigerant
Circuit Components, Replacing).
♦ The A/C compressor regulator
valve -N280- is not available as
a replacement part for all A/C
compressors. If the A/C com‐
pressor regulator valve -N280- is
not available as an individual A/
C compressor part (different ver‐
sions), then the entire A/C com‐
pressor must be replaced. Refer
to the Parts Catalog.
2 - Compressor
❑ for removing the compressor from bracket and re-installing in vehicles with a 6-cylinder engine, refer to
⇒ “3.7 Compressor on Bracket, Removing and Installing”, page 27 1).
❑ On an 8-cylinder vehicle, it is necessary to evacuate the refrigerant circuit in order to remove the A/C
compressor from the bracket. Refer to
⇒ “16.4 Compressor, Removing and Installing (Vehicles with 8-Cylinder FSI Engine)”, page 283 (A/C
Compressor, 8-Cylinder FSI and 8-Cylinder TDI, Removing and Installing).
❑ On a 12-cylinder vehicle, it is necessary to evacuate the refrigerant circuit in order to remove the A/C
compressor from the bracket. Refer to
⇒ “16.3 Compressor, Removing and Installing (Vehicles with 12-Cylinder TDI Engine)”, page 280 (A/C
Compressor, 12-Cylinder TDI, Removing and Installing).
❑ When installing refrigerant lines/hoses and pertaining bracket, make sure there is a sufficient gap be‐
tween belt, bracket and belt pulley
❑ Depending on time period of production and on engine, compressor construction type may vary. Refer
to the Parts Catalog.
❑ At the start of production compressors manufactured by “Denso” are installed. Refer to the Parts Catalog
und ⇒ Refrigerant R134a Servicing; Rep. Gr. 87 ; A/C System General Information (Refrigerant R134a,
Servicing; Refrigerant R134a Capacities, Refrigerant Oil and Approved Refrigerant Oil).
❑ These compressors are available as replacement parts with different oil fill capacities, therefore note
capacity on compressor and the exact part number. Refer to the Parts Catalog. The reason for the
different oil capacities in the compressor for an otherwise identical refrigerant circuit lies in the design of
the compressor itself, note these oil capacities. Too much oil in the circuit leads to higher pressures and
reduces cooling performance of the system. Too little oil may lead to lubrication problems in the com‐
pressor.
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
3. Refrigerant Circuit 13

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
❑ Depending on the compressor type and the refrigerant circuit design (one or two evaporators), different
refrigerant and refrigerant oil capacities are used for the refrigerant circuit. Refer to ⇒ Refrigerant R134a
Servicing; Rep. Gr. 87 ; A/C System General Information (Refrigerant R134a, Servicing; Refrigerant
R134a Capacities, Refrigerant Oil and Approved Refrigerant Oil).
3 - Compressor Belt Pulley/Drive Unit
❑ There are different versions (depending on the engine). Refer to the Parts Catalog.
❑ For replacing the A/C compressor belt pulley (vehicles with a 6-cylinder engine, 8-cylinder TDI engine
or 12-cylinder TDI engine) 1), refer to ⇒ “4 Compressor Pulley”, page 34 .
❑ For removing and installing the ribbed belt (vehicles with a 6-cylinder engine, 8-cylinder TDI engine or
12-Cylinder TDI engine) 1), refer to the ⇒ Engine Mechanical; Rep. Gr. 19 ; Cylinder Block, Belt Pulley
Side; Ribbed Belt, Removing and Installing .
❑ For the correct ribbed belt allocation (for vehicles with a 6-cylinder engine, 8-cylinder TDI engine or 12-
cylinder TDI engine), refer to the Parts Catalog.
❑ For removing and installing the A/C Compressor drive unit (vehicles with an 8-cylinder FSI engine), refer
to
⇒ “16.5 Compressor Drive Unit, Checking and Replacing (Vehicles with 8-Cylinder FSI Engine)”,
page 290 (for removing the A/C compressor, refer to
⇒ “16.4 Compressor, Removing and Installing (Vehicles with 8-Cylinder FSI Engine)”, page 283 ).
Note
♦ An overload safeguard is instal‐
led between the belt pulley/drive
unit and driveshaft, this protects
the compressor belt/engine in
the event that the compressor is
seized or does not move freely.
♦ If compressor is runs with resist‐
ance, overload safeguard inter‐
rupts power transmission to
compressor.
♦ Rubber elements are installed
between belt pulley/drive unit
and compressor driveshaft, vi‐
brations which may occur during
compressor operation may be
dissipated via these rubber ele‐
ments (damper function at tor‐
que fluctuations).
♦ Depending on compressor type,
different belt pulleys are installed
on compressor. Refer to
⇒ “4 Compressor Pulley”,
page 34 .
Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
14 Rep. Gr.87 - Air Conditioning