General, Technical Data (Refrigerant r134a Servicing (avant)) Audi A4 B8

REFRIGERANT R134A CAPACITIES

1. «CAPACITIES, AUDI A1 (8X_) FROM MY 11»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a1-8x_-from-my)
2. «CAPACITIES, AUDI A2 (8Z_) FROM MY 01»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a2-8z_-from-my)
3. «CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a3-8l_-1997-through)
4. «CAPACITIES, AUDI A3 (8P_) FROM MY 04»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a3-8p_-from-my)
5. «CAPACITIES, AUDI TT (8J_) FROM MY 07»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-tt-8j_-from-my)
6. «CAPACITIES, AUDI 80 (8A_/8C_), AUDI COUPE (8B_) AND AUDI CABRIOLET (8G_), FROM MY 2002»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-80-8a_8c_-audi-coupe)
7. «CAPACITIES, AUDI A4 (8D_), FROM MY 95»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a4-8d_-from-my)
8. «CAPACITIES, A4 (8E_) 01 AND AUDI A4 CABRIOLET (8H_), FROM MY 03»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-a4-8e_-01-and-audi)
9. «CAPACITIES, AUDI A4 (8K_) FROM MY 2008, AUDI A5 COUPE (8T_) FROM MY 2008, AUDI Q5 (8R_) FROM MY 2008, AUDI A5 CABRIOLET (8F_) FROM MY 2009 AND AUDI Q5 HYBRID (8R_) FROM 2011»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a4-8k_-from-my)
10. «CAPACITIES, AUDI 100 AND AUDI A6 (4A_), FROM MY 98»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-100-and-audi-a6)
11. «CAPACITIES, AUDI A6 (4B_) FROM MY 1998 AND AUDI ALLROAD (4B_) FROM MY 2005»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a6-4b_-from-my)
12. «CAPACITIES, AUDI A6 (4F_), FROM MY 05»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a6-4f_-from-my)
13. «CAPACITIES, AUDI A6 (4G_) FROM MY 11 AND AUDI A7 (4G_) FROM MY 11»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a6-4g_-from-my)
14. «CAPACITIES, AUDI V8 (4C_) FROM MY 94»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-v8-4c_-from-my)
15. «CAPACITIES, AUDI A8 (4D_) FROM MY 94»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a8-4d_-from-my)
16. «CAPACITIES, AUDI A8 (4E_) FROM MY 03»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a8-4e_-from-my)
17. «CAPACITIES, AUDI A8 (4H_) FROM MY 10, AUDI A8 HYBRID (4H_) FROM 2012»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a8-4h_-from-my)
18. «CAPACITIES, AUDI Q7 (4L_), FROM MY 06»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-q7-4l_-from-my)
19. «CAPACITIES, AUDI R8 (42_) FROM MY 08»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-r8-42_-from-my)

CAPACITIES, AUDI A1 (8X_) FROM MY 11

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Denso, Sanden (or Delphi) with A/C compressor regulator valve -N280-. Refer to «Removal and Installation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Depending on time period of production and depending on engine, different A/C compressors are installed (these A/C compressors do not have an A/C clutch) At Start Of Production, A/C compressors manufactured by Denso type 6 SEU 14C or Sanden type 7 PXE 16 were installed. Refer to Removal and Installation . Depending on the engine, an A/C compressor manufactured by Delphi type 6 CVC 140 will be installed at a later point in time (introduction still open). Refer to Removal and Installation .

CAPACITIES, AUDI A2 (8Z_) FROM MY 01

Features of the refrigerant system

1. Restrictor (colored).
2. Reservoir.
3. A/C compressor manufacturer Denso without A/C clutch and with A/C Compressor Regulator Valve -N280

Note. Replacement restrictors with different holes are available (yellow colored 1.54 mm, red colored 1.42 mm). Depending on manufacturer, color of red restrictor may tend more towards orange. To avoid altering the cooling output of the air conditioner, restrictors with the same hole diameter must only be installed. A restrictor with a smaller hole (red colored) and a condenser with smaller internal volume were introduced as of model year 2002. The capacity has therefore been slightly modified (condenser -70 g, smaller restrictor +50 g). Refer to Description and Operation .

CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. A/C compressor manufactured by Sanden or Zexel / Valeo. Refer to «Removal and Installation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Capacities Audi A3 (8L_) 1997 up to 2004

Note. Exclusive use was made at the start of production of Sanden A/C compressors. As of model year 1999, use was also made of Zexel compressors. Refer to Description and Operation . If no condenser with a flat pipe width of 20 mm is available for Audi A3 as a replacement part, and a condenser with a flat pipe width of 16 mm is installed, only 650 + / - 20 g of refrigerant instead of 750 + 50 g may be filled in. In addition, capacity specification must be changed accordingly on sticker (to do so, please observe notes for Audi TT CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999 ). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Capacities Audi TT (8N_) from MY 99

Note. Exclusive use was made at the start of production of Sanden A/C compressors. As of model year 1999, use was also made of Zexel compressors. Refer to Description and Operation . As of calendar year 2006, the Zexel / Valeo identification was changed to Valeo. There was a change in production for Audi TT as of 10.03 (from vehicle identification number (VIN) 8N41015239) from condenser with part number "1J0 820 411 J" (flat pipe width of 20 mm) to condenser with part number " 8N0 820 411 A" (flat pipe width of 16 mm), refer to DETERMINING DIMENSIONS OF FLAT PIPES FROM CONDENSER . From 06.04 to 08.04, a certain number of vehicles not specified were equipped again with condensers having a flat pipe width of 20 mm. Condensers with a flat pipe width of 16 mm require 120 g less of refrigerant than condensers with flat pipe width of 20 mm. On the Audi TT, from 10.2003 (from VIN 8N41015239) through 06.04, a condenser with a 16 mm flat pipe width (part number " 8N0 820 411 A") was installed filled with 750 + 50 grams of refrigerant, and in addition to this, these vehicles have label with the incorrect filling quantity: 750 grams (or 700 grams in 06.04) instead of 650 grams, refer to STICKER FOR CAPACITY OF REFRIGERANT R134A . Due to overfilling of the system, the A/C compressor may be switched off under certain circumstances (for example high ambient temperatures) since the pressure in the refrigerant circuit is too high; in addition, drivers may complain about the engine performance (for example, rumbling and buzzing sounds, the engine is heavier loaded as the A/C compressor is working steadily against the excessive pressure). Solution: drain refrigerant circuit, then refill correct capacity and replace sticker with one indicating correct capacity specification, or cross out wrong capacity specification on sticker and note correct capacity, for example using a waterproof marker. If condenser is replaced, observe flat pipe dimensions. If a condenser with another flat pipe dimension is installed, the sticker specifying the capacity for refrigerant R134a is also to be replaced, or the old capacity specification is to be removed and the new capacity is to be noted, for example, using a waterproof marker.

Scheme 308

1. Flat pipes of condenser -A
2. Width of flat pipes -B

STICKER FOR CAPACITY OF REFRIGERANT R134A

If condenser is replaced, observe flat pipe dimensions. If a condenser with different dimensions is installed, the sticker -A- specifying the capacity for refrigerant R134a is also to be replaced, or the old capacity specification is to be removed and the new capacity is to be noted, for example, using a waterproof marker.

Scheme 309

CAPACITIES, AUDI A3 (8P_) FROM MY 04

Note. Applies to the Audi A3, Audi A3 Sportback, Audi RS3 and Audi A3 Cabriolet.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. A/C compressor made by Denso, Delphi, Sanden or Zexel / Valeo with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Depending on time period of production and depending on engine, different A/C compressors are installed (these A/C compressors do not have an A/C clutch) At the start production, Denso 7 SEU 16 A/C compressors were installed. As of model year 2004, there was a running change to Denso compressor type 7 SEU 17. With a gradual introduction as of MY 2004 and depending on the engine, Zexel compressors (type DSC17E) and Sanden compressors (type PXE16) are installed. Refer to Description and Operation . As of MY 2008, and depending on the engine, A/C compressors made by Denso (6 SEU 14) and Delphi are being installed. Refer to Description and Operation . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

CAPACITIES, AUDI TT (8J_) FROM MY 07

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Denso or Sanden (or Delphi) A/C compressors, with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. At the start of production, Denso A/C compressors 6 SEU 14 were installed; these A/C compressor do not have an A/C clutch (driven by the engine). Compressors from other manufacturers may also be installed at a later time, depending on the engine. Refer to Description and Operation . As of MY 2008, on certain engines, Sanden A/C compressors (type PXE16) were installed; they do not have an A/C clutch (it is driven by the engine). Refer to Description and Operation . With a gradual introduction starting from MY 2011 and depending on the engine, Delphi A/C compressors are installed. Refer to Removal and Installation .

CAPACITIES, AUDI 80 (8A_/8C_), AUDI COUPE (8B_) AND AUDI CABRIOLET (8G_), FROM MY 2002

Features of the refrigerant system

1. Restrictor (not colored).
2. Reservoir
3. A/C compressors made by Zexel / Valeo. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Replacement restrictors with different holes are available. If these vehicles are equipped with a yellow colored restrictor, add 50 g more refrigerant than specified in the table. After charging, amend capacity stated on label or affix label indicating new capacity. In order to distinguish between the two restrictor versions, the one with the smaller hole (1.54 mm) is yellow colored. The restrictor with the larger hole (1.83 mm) is not colored. Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

CAPACITIES, AUDI A4 (8D_), FROM MY 95

Note. Applies also to the Audi RS 4

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Restrictors with a modified hole have been installed at the factory since November 1997 (yellow colored). The capacity was increased by 50 g for vehicles with yellow colored restrictor. In order to distinguish between the two restrictor versions, the one with the smaller hole (1.54 mm) is yellow colored. The restrictor with the larger hole (1.83 mm) is not colored. The Audi A4 was equipped with different A/C compressors depending on engine and production period. Exclusive use was made at the start of production of Zexel / Valeo A/C compressors. As of MY 1996, Denso A/C compressors were gradually introduced for vehicles with 6-cylinder engines. Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. Replacement restrictors with different holes (not colored, yellow colored, red colored) are available. If a vehicle is equipped with a different restrictor, add more or less refrigerant depending on type (--> table). After charging, amend capacity stated on label or affix label indicating new capacity. Depending on manufacturer, color of red restrictor may tend more towards orange. As of November 1998, Audi A4 models have also been equipped with AWG condensers (initially approximately 10, 000 vehicles, from vehicle identification number (VIN) 8DXA 065 253 to 8DXA 077 026). The specified capacity for vehicles with these condensers differs from those with Showa condensers. The condensers can be identified on the basis of certain characteristic features. Refer to DISTINGUISHING FEATURES . If the condenser installed is replaced by one with a different part number, check the capacity indicated on the label in the vehicle and amend if necessary or affix a label with the correct capacity over the existing one. Refer to Description and Operation .

DISTINGUISHING FEATURES

Different manifolds

Scheme 310

A - Manifold on Showa condenser

B - Manifold on AWG condenser

Different connections to pressure switch.

Scheme 311

A - Connection area on Showa condenser

B - Connection area on AWG condenser

CAPACITIES, A4 (8E_) 01 AND AUDI A4 CABRIOLET (8H_), FROM MY 03

Note. Applies also to the Audi RS 4

Features of the refrigerant system

1. Restrictor (yellow or red colored).
2. Reservoir
3. Denso A/C compressor with A/C compressor regulator valve -N280- (without A/C clutch)

Note. Replacement restrictors with different holes are available: yellow colored 1.54 mm, red colored 1.42 mm. Depending on manufacturer, color of red restrictor may tend more towards orange. To avoid altering the cooling output of the air conditioner, red or yellow colored restrictors must only be installed. Yellow colored restrictors were installed in model year 2001. Red colored restrictors were installed as of model year 2002. The restrictor modification (a red colored restrictor may also be installed in vehicles of model year 2001 instead of a yellow colored restrictor) does not alter the capacity for these vehicles. Depending on time period of production and depending on engine, different A/C compressors are installed (these A/C compressors do not have an A/C clutch) At the start production, Denso A/C compressors 6 SEU 12 and 7 SEU 16 were installed. As of model year 2004, there was a running change to other Denso compressor types (6 SEU 14 and 7 SEU 17). Refer to Description and Operation (vehicle-specific repair information). The Audi RS 4 has an condenser with a smaller internal volume, therefore the capacity for this model is less than for other models.

CAPACITIES, AUDI A4 (8K_) FROM MY 2008, AUDI A5 COUPE (8T_) FROM MY 2008, AUDI Q5 (8R_) FROM MY 2008, AUDI A5 CABRIOLET (8F_) FROM MY 2009 AND AUDI Q5 HYBRID (8R_) FROM 2011

Note. Applies also to the Audi S5 and the Audi RS 5.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Refrigerant pipe with inner heat exchanger
4. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. For all vehicles except for the Audi Q5 Hybrid, the mechanically driven A/C compressors manufactured by Denso (for example, the type "6 SEU 14" for vehicles with the 4 and 6 cylinder engines and the type "7 SEU 17" for vehicles with the 8 cylinder engine) are installed at the start of production. Compressors from other manufacturers may also be installed at a later time. Refer to Description and Operation (vehicle-specific Repair Information). The Audi RS 5 has an condenser with a smaller internal volume, therefore the capacity for this model is less than for other models of this series. An electrically driven A/C compressor manufactured by Denso (electrical A/C compressor -V470- with A/C compressor control module -J842-) is installed at the start of production for the Audi Q5 Hybrid. There is no A/C compressor regulator valve -N280- present in this A/C compressor.

CAPACITIES, AUDI 100 AND AUDI A6 (4A_), FROM MY 98

Features of the refrigerant system

1. Restrictor (not colored)
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo, Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. If a vehicle is equipped with a yellow colored restrictor as replacement for a non-colored restrictor, add 50 g more refrigerant than specified in the table. In addition, the capacity specified on the label in the vehicle is to be checked and amended if necessary, or the existing label is to be replaced with one indicating the correct capacity (affix over old label). Restrictors with a modified hole have been installed at the factory since November 1997 (colored). In order to distinguish between the two restrictor versions, the one with the smaller hole (1.54 mm) is yellow colored. The restrictor with the larger hole (1.83 mm) is not colored. As of calendar year 2006, the Zexel / Valeo identification was changed to Valeo. From September 1994, production was gradually switched from condenser 4A0 260 403 AB to condenser 4A0 260 403 AC. The refrigerant capacity of 750+50 g applies to all Audi 100 (regardless of condenser). Only condensers with part number 4A0 260 403 AC are now available as replacement parts (if necessary, make use of label, part no. 8A0 010 126 P). After charging refrigerant circuit of vehicles manufactured up to October 1994, check capacity stated on label in vehicle and amend if necessary of affix label, part no. 8A0 010 126 P (modified capacity). Refer to Description and Operation .

CAPACITIES, AUDI A6 (4B_) FROM MY 1998 AND AUDI ALLROAD (4B_) FROM MY 2005

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo, Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Restrictors with a modified hole have been installed at the factory since November 1997 (yellow colored). The capacity was increased by 50 g for vehicles in which a yellow colored restrictor was installed. In order to distinguish between the two restrictor versions, the one with the smaller hole (1.54 mm) is yellow colored. The restrictor with the larger hole (1.83 mm) is not colored. If a vehicle is equipped with a colored restrictor as replacement for a non-colored restrictor, add 50 g more refrigerant than specified in the table. In addition, the capacity specified on the label in the vehicle is to be checked and amended if necessary, or the existing label is to be replaced with one indicating the correct capacity (affix over old label). The Audi A6 are equipped with different A/C compressors depending on engine and production period. Production was gradually switched in August/September 1998 from air conditioner unit version 1 to air conditioner unit version 2. A reduction in capacity was achieved as the evaporator was also modified together with the air conditioner unit. The two air conditioner unit versions can be identified on the basis of certain characteristics described in the vehicle-specific repair information. Refer to Description and Operation . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Note. Condensers with A/C pressure switch -F129- or High Pressure Sensor -G65- are supplied for production as part number XXXXXX 401 X. As a replacement part, this condenser is supplied without A/C pressure switch -F129- or high pressure sensor -G65- as part number XXXXXX 403 X. From 10.98 to 12.98, vehicles with 6-cyinder. diesel engine (initially about 10, 000) were equipped with condensers of a different design. The capacity is different for vehicles with these condensers. The condensers can be identified on the basis of certain characteristics and the part number, refer to DETERMINING DIMENSIONS OF FLAT PIPES FROM CONDENSER . The Audi A6 are equipped with different A/C compressors depending on engine and production period. On condenser replacement, observe part number index (different flat pipe versions, flat pipe dimensions 16 x 1.7 mm, 18 mm x 1.7 mm or 20 mm x 3 mm) and the different capacities involved. If a condenser with a different part number index is installed, the capacity specified on the label must be checked and amended if necessary or a label indicating the modified capacity must be affixed over the existing label. The part number can be found on a sticker affixed on the underside of the condenser. As of 04.99, production was gradually switched from condensers with flat pipe dimensions 20 mm x 3 mm to condensers with flat pipe dimensions 18 mm x 1.7 mm or 16 mm x 1.7 mm. The change in production took place gradually during the course of 1999 depending on the engine and existing supplies of the different versions. For vehicles as of 04.99 equipped with 6-cylinder diesel engine, a condenser with index D, G, R or K may be installed. Pay attention to the different capacities. Refer to Description and Operation .

Note. The 8-cylinder Audi A6 has a Denso A/C compressor. Production was gradually switched in August/September 1998 from air conditioner unit version 1 to air conditioner unit version 2. Vehicles with 8-cylinder engine are only equipped with air conditioner unit as of version 2. The different air conditioner unit versions can be identified on the basis of certain characteristics described in the repair information. Refer to Description and Operation (vehicle-specific repair information). For vehicles with 8-cylinder engines, different condensers were installed. Exclusive use was made for USA vehicles of condensers with part no. 4B3 260 401 (403) C, D, E. In March 1999, production was gradually switched from condensers with part no. 4B3 260 401 (403) B to condensers with part no. 4B3 260 401 (403) C. If the condenser installed is replaced by a condenser with a different part number, the capacity specified on the label must be amended and, if necessary, the label indicating the modified capacity must be affixed over the existing label. The part number can be found on a sticker attached to the bottom of the condenser. Refer to Description and Operation .

DETERMINING DIMENSIONS OF FLAT PIPES FROM CONDENSER

Note. Production was gradually switched as of calendar week 45, 1998 (initially for Audi A6 with 6-cylinder diesel engine) to a condenser with smaller flat pipes. Observe part number on condenser replacement (sometimes the only distinguishing feature).

Condensers -A- with flat pipe dimensions -B- = 20 mm and -C- = 3.0 mm must be filled with more refrigerant than condensers -D- with flat pipe dimensions -E- = 18 mm or 16 mm and -F- = 1.7 mm.

Scheme 312

If condenser is replaced, observe flat pipe dimensions. If a condenser with different dimensions is installed, the sticker -A- specifying the capacity for refrigerant R134a is also to be replaced, or the old capacity specification is to be removed and the new capacity is to be noted, for example, using a waterproof marker.

Scheme 313

CAPACITIES, AUDI A6 (4F_), FROM MY 05

Note. Applies also to the Audi S6 and the Audi RS 6.

Features of the refrigerant system

1. Red colored restrictor.
2. Reservoir
3. Denso A/C compressor with A/C compressor regulator valve -N280- (without A/C clutch)

Note. Replacement restrictors with different holes are available: yellow colored 1.54 mm, red colored 1.42 mm. Depending on manufacturer, color of red restrictor may tend more towards orange. To avoid altering the cooling output of the air conditioner, red colored restrictors must only be installed. Different A/C compressors are installed depending on their version. Refer to Description and Operation . In contrast to vehicles with other engines, vehicles with the 10-cylinder TFSI engine (Audi R S6) have a condenser with a smaller interior volume installed. For this reason, the refrigerant fill volume is slightly less in a 10-cylinder TFSI engine than in other engines.

CAPACITIES, AUDI A6 (4G_) FROM MY 11 AND AUDI A7 (4G_) FROM MY 11

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Refrigerant pipe with inner heat exchanger
4. Denso A/C compressors with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. At the start of production, the A/C compressors manufactured by Denso (type 6 SEU 14) were installed. A/C compressors from other manufacturers or another type may also be installed at a later time. Refer to Description and Operation (vehicle-specific repair information).

CAPACITIES, AUDI V8 (4C_) FROM MY 94

Features of the refrigerant system

1. Restrictor (not colored).
2. Reservoir
3. A/C compressors made by Zexel / Valeo. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Replacement restrictors with different holes are available. If these vehicles are equipped with a yellow colored restrictor, add 50 g more refrigerant than specified in the table. After charging, amend capacity stated on label or affix label indicating new capacity. In order to distinguish between the different restrictor versions, the restrictors with a smaller hole are colored (yellow or red). The red colored restrictor is not to be installed into these vehicles. Depending on manufacturer, color of red restrictor may tend more towards orange. Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

CAPACITIES, AUDI A8 (4D_) FROM MY 94

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Restrictors with a modified hole have been installed at the factory since November 1997 (yellow colored). The capacity was increased by 50 g for vehicles with a yellow colored restrictor. In order to distinguish between the different restrictor versions, the restrictors with a smaller hole are yellow (1.54 mm) or red (1.42 mm) colored. The restrictor with the larger hole (1.83 mm) is not colored. If a vehicle is equipped with a yellow colored restrictor as replacement for a non-colored restrictor, add 50 g more refrigerant than specified in the table. In addition, the capacity specified on the label in the vehicle is to be checked and amended if necessary, or the existing label is to be replaced with one indicating the correct capacity (affix over old label). The red colored restrictor is not to be installed into these vehicles. Exclusive use was made at the start of production of Zexel / Valeo A/C compressors. As of model year 1996, production was gradually switched to Denso compressors. Refer to Description and Operation . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

CAPACITIES, AUDI A8 (4E_) FROM MY 03

Features of the refrigerant system

1. Red colored restrictor.
2. Reservoir
3. Denso A/C compressor with A/C compressor regulator valve -N280- (without A/C clutch)

Note. Replacement restrictors with different holes are available: yellow colored 1.54 mm, red colored 1.42 mm. Depending on manufacturer, color of red restrictor may tend more towards orange. To avoid altering the cooling output of the air conditioner, red colored restrictors must only be installed. Different A/C compressors are installed depending on their version. Refer to Description and Operation .

CAPACITIES, AUDI A8 (4H_) FROM MY 10, AUDI A8 HYBRID (4H_) FROM 2012

Features of the refrigerant system

1. Expansion Valve
2. Depending on the vehicle equipment level with one or two evaporators
3. Refrigerant pipe with inner heat exchanger
4. Dryer cartridge in fluid reservoir on condenser
5. Denso A/C compressors with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. For vehicles with 8 cylinders. The refrigerant oil quantity must be increased in the refrigerant circuit for TDI engines for vehicles with VIN numbers from 4H_ BN 018846. To differentiate, the refrigerant quantity must be slightly reduced. Since the filling capacity information on the information label does not change, proceed as follows: For vehicles built through the designated VIN, check whether the refrigerant oil capacity was possibly filled during a previous workshop visit, if not, fill the refrigerant circuit with an additional 50 cubic cm of refrigerant oil. Next, write down the corresponding filling capacity for the refrigerant in the information label with a waterproof marker and fill the refrigerant circuit with the above mentioned refrigerant quantity. Finally, document the performed changes in the vehicle data. For vehicles constructed within the applicable VIN range, check the specified filling capacity for the refrigerant in the information label and if necessary write down the corresponding quantities with a waterproof marker and then fill the refrigerant circuit with the specified refrigerant quantity For all vehicles except for the Audi A8 Hybrid, the mechanically driven A/C compressors manufactured by "Denso" are installed. Compressors from other manufacturers may also be installed at a later time. Refer to Removal and Installation (vehicle-specific Repair Information). An electrically driven A/C compressor manufactured by "Denso" (electrical A/C compressor -V470- with A/C compressor control module -J842-) is installed at the start of production for the Audi A8 Hybrid. There is no A/C compressor regulator valve -N280- present in this A/C compressor. A/C compressors with a refrigerant oil quantity of 200 cubic cm are installed at the start of production for Audi A8 Hybrid vehicles, shortly after the start of production, the refrigerant oil quantity is reduced to 160 cubic cm. Always fill the vehicles when servicing to 1080 +/- 15 g with refrigerant (write the capacity information on the information label with a waterproof marker if necessary) regardless of the refrigerant oil quantity.

CAPACITIES, AUDI Q7 (4L_), FROM MY 06

Features of the refrigerant system

1. Expansion Valve
2. Depending on the vehicle equipment level with one or two evaporators
3. Dryer cartridge in fluid reservoir on condenser
4. Denso A/C compressors with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

CAPACITIES, AUDI R8 (42_) FROM MY 08

Features of the refrigerant system

1. Red colored restrictor.
2. Reservoir
3. Two condensers switched in sequence
4. Denso A/C compressors with an A/C compressor regulator valve -N280-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. Replacement restrictors with different holes are available: yellow colored 1.54 mm, red colored 1.42 mm. Depending on manufacturer, color of red restrictor may tend more towards orange. To avoid altering the cooling output of the air conditioner, red colored restrictors must only be installed.

REFRIGERANT OILS

Note. The oils used with refrigerant R12 are not suitable for refrigerant R134a. The name of the compressor manufacturer Nippondenso has been changed to Denso. The special refrigerant oil (for use with refrigerant circuits R134a only) is no longer commercially available. Refrigerant oils specifically designed for each compressor can therefore be obtained from the replacement parts program The use of other refrigerant oils could cause system failure, as they do not always mix and thus circulate with refrigerant R134a (for compressor lubrication). The Zexel / Valeo, Denso, Delphi and Sanden A/C compressors all have different refrigerant oils. Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. The refrigerant oil (G 052 300 A2) for use in refrigerant circuits with Denso compressors (old name Nippondenso) is also included in the retrofit kit (part number 4A0 298 107 A). For refrigerant circuits with Zexel or Sanden compressors use is to be made of refrigerant oil with part number G 052 154 A2. Refrigerant oils G 052 154 A2 and G 052 300 A2 can be used in a Delphi A/C compressor. For refrigerant circuits with Zexel / Valeo compressor, use can be made of both the refrigerant oil (G 052 154 A2) and the refrigerant oil (G 052 200 A2) contained in the retrofit kit (part number 4A0 298 107). Currently the electrically driven A/C compressor (for example, for the Audi Q5 Hybrid manufactured by Denso) is filled with the same refrigerant oil as the mechanically driven A/C compressor (refer to the type plate on the A/C compressor).

REFRIGERANT OIL CAPACITIES

Note. The allocation for the Zexel / Valeo, Sanden or Denso) A/C compressors can be found in the vehicle-specific repair information. Refer to Removal and Installation (vehicle-specific repair information). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. With Zexel, Denso and Sanden compressors, the amount of refrigerant oil in the replacement compressor corresponds to the total quantity of oil to be added. On A/C compressor replacement, the quantity of refrigerant oil in the A/C compressor to be installed must therefore be adjusted (an incorrect refrigerant oil quantity will damage the A/C compressor). When pouring refrigerant oil out of replacement A/C compressor (or malfunctioning A/C compressor), a small quantity of oil generally remains in the A/C compressor (20 to 30 cm 3 ). This amount of refrigerant oil does not affect the function of the air conditioner and can therefore be ignored (always remains in A/C compressor). Following initial switch-on, the refrigerant oil is distributed throughout the entire refrigerant circuit. The specified capacities for the refrigerant oil apply if no other different specifications given for the S and RS. Refrigerant oil capacities when replacing refrigerant circuit components refer to REMOVAL AND INSTALLATION and Removal and Installation , (vehicle-specific repair information).

1. «CAPACITIES, AUDI A1 (8X_) FROM MY 11»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
2. «CAPACITIES, AUDI A2 (8Z_) FROM MY 01»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
3. «CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
4. «CAPACITIES, AUDI A3 (8P_) FROM MY 04»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
5. «CAPACITIES, AUDI TT (8J_) FROM MY 07»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
6. «CAPACITIES, AUDI 80 (8A_/8C_), AUDI COUPE (8B_) AND AUDI CABRIOLET (8G_), FROM MY 2002»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
7. «CAPACITIES, AUDI A4 (8D_), FROM MY 95»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
8. «CAPACITIES, A4 (8E_) 01 AND AUDI A4 CABRIOLET (8H_), FROM MY 03»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
9. «CAPACITIES, AUDI A4 (8K_) FROM MY 2008, AUDI A5 COUPE (8T_) FROM MY 2008, AUDI Q5 (8R_) FROM MY 2008 AND AUDI A5 CABRIOLET (8F_) FROM MY 2009 AND AUDI Q5 HYBRID (8R_) FROM 2011»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a4-8k_-from-my)
10. «CAPACITIES, AUDI 100 AND AUDI A6 (4A_), FROM MY 98»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
11. «CAPACITIES, AUDI A6 (4B_) 98 AND AUDI ALLROAD FROM MY 05»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a6-4b_-98-and)
12. «CAPACITIES, AUDI A6 (4F_), FROM MY 05»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
13. «CAPACITIES, AUDI A6 (4G_) FROM MY 11 AND AUDI A7 (4G_) FROM MY 11»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
14. «CAPACITIES, AUDI V8 (4C_) FROM MY 94»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
15. «CAPACITIES, AUDI A8 (4D_) FROM MY 94»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
16. «CAPACITIES, AUDI A8 (4E_) FROM MY 03»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
17. «CAPACITIES, AUDI A8 (4H_) FROM 2010, AUDI A8 HYBRID (4H_) FROM 2012»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__capacities-audi-a8-4h_-from-2010)
18. «CAPACITIES, AUDI Q7 (4L_), FROM MY 06»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)
19. «CAPACITIES, AUDI R8 (42_) FROM MY 08»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant)

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Compressors from various manufacturers with an A/C compressor regulator valve -N280- (without an A/C clutch). Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Different A/C compressors are installed depending on production period and engine. At Start Of Production, A/C compressors manufactured by Denso type 6 SEU 14C or Sanden type 7 PXE 16 were installed. Refer to Removal and Installation . Depending on the engine, an A/C compressor manufactured by Delphi type 6 CVC 140 will be installed at a later point in time (introduction still open). Refer to Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Refer to the Specifications . The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor with A/C compressor regulator valve -N280- (without A/C clutch)
4. A/C compressors made by Denso, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . As the A/C compressor and engine always operate at the same time and the entire quantity of refrigerant oil is contained in the A/C compressor, the circuit must be completely assembled before starting the engine. Refer to Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. A/C compressor manufactured by Sanden or Zexel / Valeo. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Exclusive use was made at the start of production of Sanden A/C compressors. As of model year 1999, use was also made of Zexel compressors. Refer to Description and Operation . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Note. Applies to the Audi A3, Audi A3 Sportback, Audi RS3 and Audi A3 Cabriolet.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Compressors from various manufacturers with an A/C compressor regulator valve -N280- (without an A/C clutch). Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Different A/C compressors are installed depending on production period and engine. At start of production, exclusive use was made of A/C compressors 7 SEU 16 from Denso (for example, A/C compressor with part no. 1K0 820 803 up to index D). In model year 2004 (as of approximately 10.03), a gradual change was made to a different type of Denso A/C compressor (7 SEU 17 for example, A/C compressor with part number 1K0 820 803 as of index E). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. As of MY 2008, and depending on the engine, A/C compressors made by Denso (6 SEU 14) and Delphi are being installed. Refer to Description and Operation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Refer to the Removal and Installation . The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Denso or Sanden A/C compressors, with an A/C compressor regulator valve -N280- (without an A/C clutch). Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement A/C compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . At the start of production, Denso A/C compressors 6 SEU 14 were installed; these A/C compressor do not have an A/C clutch (driven by the engine). Compressors from other manufacturers may also be installed at a later time, depending on the engine. Refer to Description and Operation . As of MY 2008, on certain engines, Sanden A/C compressors (type PXE16) were installed; they do not have an A/C clutch (it is driven by the engine). Refer to Description and Operation . With a gradual introduction starting from MY 2011 and depending on the engine, Delphi A/C compressors are installed. Refer to Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Refer to the Removal and Installation . The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Restrictor (not colored).
2. Reservoir
3. A/C compressors made by Zexel / Valeo, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . The Audi A4 has different A/C compressors installed depending on the engine and the time of production. Refer to Description and Operation Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Denso A/C compressors with an A/C compressor regulator valve -N280- (without an A/C clutch, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . The Audi A4 is equipped with different A/C compressors depending on engine and production period. The replacement part for this A/C compressor has different oil capacities. Pay close attention to the exact part number. Refer to Description and Operation (vehicle-specific repair information) The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

CAPACITIES, AUDI A4 (8K_) FROM MY 2008, AUDI A5 COUPE (8T_) FROM MY 2008, AUDI Q5 (8R_) FROM MY 2008 AND AUDI A5 CABRIOLET (8F_) FROM MY 2009 AND AUDI Q5 HYBRID (8R_) FROM 2011

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Refrigerant pipe with inner heat exchanger.
4. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . At start of production, A/C compressors manufactured by Denso (type 6 SEU 14) on 4 and 6 cylinder vehicles Engine and type 7 SEU 17 on vehicles with 8 cylinders engine, this A/C compressor does not have an A/C clutch (it is driven by the engine). Compressors from other manufacturers may also be installed at a later time, depending on the engine. Refer to Description and Operation (vehicle-specific repair information). An electrically driven A/C compressor manufactured by "Denso" (electrical A/C compressor -V470- with A/C compressor control module -J842-) is installed at the start of production for the Audi Q5 Hybrid. There is no A/C compressor regulator valve -N280- present in this A/C compressor. As of MY 12, certain engines and A/C compressors that in addition to the A/C compressor regulator valve have an A/C clutch -N25- attached to the belt pulley. Refer to Description and Operation (vehicle-specific repair information). These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Refer to the Removal and Installation (vehicle-specific repair information). A/C compressors with a refrigerant oil quantity of 160 cubic cm are installed at the start of production for Audi Q5 Hybrid vehicles, shortly after the start of production, the refrigerant oil quantity is increased to 200 cubic cm. Do not add to the refrigerant oil quantity for a vehicle in which an A/C compressor with a refrigerant oil capacity of 160 cubic cm is installed. If for example, the refrigerant circuit is flushed, a total capacity of 200 cubic cm of refrigerant must also be filled in the refrigerant circuit for this vehicle. The replacement A/C compressor already contains the correct amount of refrigerant oil. The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

CAPACITIES, AUDI A6 (4B_) 98 AND AUDI ALLROAD FROM MY 05

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Denso or Zexel / Valeo A/C compressors with A/C clutch -N25-. Refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . The Audi A6 are equipped with different A/C compressors depending on engine and production period. As of model year 2002, the Audi A6 features compressors with A/C clutch or regulator valve (different oil quantities) depending on the engine. For the Audi allroad with 6 cylinder. diesel engine, this gradual change is introduced in model year 2003. Refer to Description and Operation (vehicle-specific repair information). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . The Audi A6 are equipped with different A/C compressors depending on engine and production period. As of model year 2002, the Audi A6 features compressors with A/C clutch or regulator valve (different oil quantities) depending on the engine. For the Audi allroad with 6 cyl. diesel engine, the change is introduced gradually in model year 2003. The replacement A/C compressor with an A/C compressor regulator valve -N280- can have different oil capacities; pay close attention to the exact part number. Refer to Removal and Installation (vehicle-specific repair information). The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Note. Applies also to the Audi S6 and the Audi RS 6.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. The Audi A6 are equipped with different A/C compressors depending on engine and production period. The replacement part for this A/C compressor has different oil capacities. Pay close attention to the exact part number. Refer to Removal and Installation (vehicle-specific repair information). A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Expansion Valve
2. Fluid Reservoir
3. Refrigerant pipe with inner heat exchanger.
4. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . At the start of production, the A/C compressors manufactured by Denso (type 6 SEU 14) were installed. A/C compressors from other manufacturers or another type may also be installed at a later time. Refer to Description and Operation (vehicle-specific repair information). These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Refer to the Removal and Installation (vehicle-specific repair information). The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Restrictor (not colored).
2. Reservoir
3. Zexel / Valeo A/C compressors, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. A/C compressor manufactured by Denso or Zexel / Valeo, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . Exclusive use was made at the start of production of Zexel / Valeo A/C compressors. As of model year 1996, production was gradually switched to Denso compressors, refer to Description and Operation (vehicle-specific repair information). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . The Audi A8 is equipped with different A/C compressors depending on engine and production period. The replacement part for this A/C compressor has different oil capacities. Pay close attention to the exact part number. Refer to Removal and Installation (vehicle-specific repair information). The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

CAPACITIES, AUDI A8 (4H_) FROM 2010, AUDI A8 HYBRID (4H_) FROM 2012

Features of the refrigerant system

1. Expansion Valve
2. Depending on the vehicle equipment level with one or two evaporators
3. Refrigerant pipe with inner heat exchanger.
4. Dryer cartridge in fluid reservoir on condenser
5. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. For vehicles with 8 cylinders. Increase the refrigerant oil quantity from 130 cubic cm to 180 cubic cm in the refrigerant circuit for TDI engines for vehicles with VIN numbers from 4H_ BN 018846. To differentiate, the refrigerant quantity must be slightly reduced. Since the filling capacity information on the information label does not change, proceed as follows: For vehicles built through the designated VIN, check whether the refrigerant oil capacity was possibly filled during a previous workshop visit, if not, fill the refrigerant circuit with an additional 50 cubic cm of refrigerant oil. Next, write down the corresponding filling capacity for the refrigerant in the information label with a waterproof marker and fill the refrigerant circuit with the stated refrigerant quantity. Finally, document the performed changes in the vehicle data. For vehicles constructed within the applicable VIN range, check the specified filling capacity for the refrigerant in the information label and if necessary write down the corresponding quantities with a waterproof marker and then fill the refrigerant circuit with the specified refrigerant quantity. The same refrigerant oil quantity is filled during production for the other engines as for vehicles with an 8 cylinder TDI engine through vehicles with the VIN 4H_ BN 018845. Vehicles with an 8 cylinder TDI engine starting from the VIN 4H_ 018846 are filled with a greater amount of refrigerant oil during production. This refrigerant oil quantity applies retroactively to all vehicles with an 8 cylinder TDI engine. If the refrigerant circuit is refilled or, for example, the A/C compressor is replaced after cleaning the refrigerant circuit for vehicles with an 8 cylinder TDI engine, check the refrigerant oil quantity in the refrigerant circuit (such as in open lines or component connections or above the A/C Service Station before filling with refrigerant) and refill it with the correct quantity if necessary. If the A/C compressor is replaced without a need to clean the refrigerant circuit, adjust the refrigerant oil quantity in the newly installed A/C compressor so that it corresponds with the quantity of oil that was poured out of the old A/C compressor (and if necessary fill for corresponding vehicles through the specified VINs above) REMOVAL AND INSTALLATION . The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. Too much oil in the circuit leads to higher pressures and reduces cooling performance of the A/C system. Too little oil may lead to lubrication problems in the compressor, therefore note the specified refrigerant oil quantities. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity. For all vehicles except for the Audi A8 Hybrid, the mechanically driven A/C compressors manufactured by "Denso" are installed. Compressors from other manufacturers may also be installed at a later time. Refer to Description and Operation (vehicle-specific Repair Information). An electrically driven A/C compressor manufactured by "Denso" (electrical A/C compressor -V470- with A/C compressor control module -J842-) is installed at the start of production for the Audi A8 Hybrid. There is no A/C compressor regulator valve -N280- present in this A/C compressor. A/C compressors with a refrigerant oil quantity of 200 cubic cm are installed at the start of production for Audi A8 Hybrid vehicles, shortly after the start of production, the refrigerant oil quantity is reduced to 160 cubic cm. Do not reduce the refrigerant oil quantity for a vehicle in which an A/C compressor with a refrigerant oil capacity of 200 cubic cm is installed. If for example the refrigerant circuit is flushed, a total capacity of 160 cubic cm of refrigerant must also be filled in the refrigerant circuit for this vehicle. The replacement A/C compressor already contains the correct amount of refrigerant oil.

Features of the refrigerant system

1. Expansion Valve
2. Depending on the vehicle equipment level with one or two evaporators
3. Dryer cartridge in fluid reservoir on condenser
4. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. Too much oil in the circuit leads to higher pressures and reduces cooling performance of the A/C system. Too little oil may lead to lubrication problems in the compressor, therefore note the specified refrigerant oil quantities. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

Features of the refrigerant system

1. Restrictor
2. Reservoir
3. Two condensers switched in sequence
4. Denso A/C compressors with an A/C compressor regulator valve -N280-, refer to «Description and Operation»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

Note. The replacement compressor contains the full quantity of oil intended for the refrigerant circuit. On A/C compressor replacement, the quantity of oil in the A/C compressor is therefore to be adjusted. Refer to REMOVAL AND INSTALLATION . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different 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 compressor. Too much oil in the circuit leads to higher pressures and reduces cooling performance of the A/C system. Too little oil may lead to lubrication problems in the compressor, therefore note the specified refrigerant oil quantities. A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.

PRESSURE GAUGE, TESTS AND MEASUREMENTS

Indicators on pressure gauge

Scheme 314

1. Temperature scale for refrigerant R134a CF3-CH2F or CH2F-CF3.
2. Pressure scale

Note. Pressure is measured in different units: 1 MPa (mega Pascal) corresponds to 10 bar positive pressure or 145 psi, 1 bar absolute pressure corresponds to 0 bar positive pressure and thus to the ambient pressure (atmospheric pressure).

The pressure gauge may have one or more temperature scales next to the pressure scale. R134a scale values are allocated respectively in the vapor pressure table. Since various refrigerants create different vapor pressures at the same temperature, each temperature scale is identified for the respective refrigerant.

1. The pressure gauges makes it possible to perform the following checks and measurements.

Pressure And Temperature Measurement At Refrigerant Circuit

1. High pressure gauge measures pressure and temperature, which expand uniformly from outlet of A/C compressor via the condenser up to constriction (restrictor, or expansion valve) with A/C system switched on.
2. Low pressure gauge measures pressure and temperature, which expand uniformly from constriction (restrictor, or expansion valve) via evaporator up to input of A/C compressor with A/C system switched on.

Note. The relationship between pressure and temperature indicated on the gauges only exists in a refrigerant circuit that contains liquid or vapor, but not gas. In a gaseous state, the temperature is approximately 10° C (50°F) to 30° C (86 °F) higher than indicated on the gauge.

Verification Of Refrigerant In A Closed Vessel

Refrigerant R134a is present in a closed vessel or in a refrigerant circuit when temperature indicator on the pressure gauge matches the refrigerant temperature (standing fluid adopts the ambient temperature).

A closed vessel or a refrigerant circuit which has been switched off is empty when temperature indication on the pressure gauge is below the temperature of the refrigerant.

Note. The relationship between pressure and temperature indicated on the gauges no longer applies if no liquid is present and the pressure is built up solely by gas.

REFRIGERANT CIRCUIT, DETERMINING LEAKS

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work in the vicinity of high voltage components, perform a visual inspection of the high voltage components and cables for damages. Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES and follow the warnings when working on the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work on the high voltage components, disable the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES and read and follow the high voltage electrical system general warnings in HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

Note. Working on the refrigerant circuit with the A/C service station usually requires, although not necessary, the high voltage system to be disabled.

Disable the high voltage system

Note. Disable the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - Disable the high voltage system (Rep.Gr. 93)

Restart the high voltage system

Note. Restart the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - High voltage restart (Rep.Gr. 93)

Charge the vehicle battery using the VAS 5903 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to DIAGNOSIS AND TESTING and GENERAL INFORMATION

Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.

Note. Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active. The ready mode is displayed in the instrument cluster control module -J285- above the "powermeter". Refer to the Owners Manual. Activate and deactivate the ready mode. Refer to the Owners Manual (consult the display in the instrument cluster control module -J285-).

Vehicles with Start/Stop System

All vehicles

Note. Minor leaks can be detected using an electronic leak detector or UV leak detector lamp. This repair information describes two different methods for detecting leaks in the refrigerant circuit. These methods have been tested and result in success when used correctly. Many methods for detecting leaks in the refrigerant circuit are offered in the open market. These methods do not always have optimum results and if they are not performed exactly to the specification and may result that several components in the refrigerant circuit have leaks. Also, refrigerant circuit components can be damaged by some methods.

1. Do not repair components with leaks; always replace them.
2. Do not charge a leaking refrigerant circuit with refrigerant. Evacuate the circuit and check it for leaks before charging. Refer to «EVACUATING REFRIGERANT CIRCUIT»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-general-information-avant__evacuating-refrigerant-circuit) .

Note. Chemical materials to seal leaks in the refrigerant circuit react with air or the moisture in the air and form deposits in the refrigerant circuit and the A/C service station that lead to malfunctions in the valves and other components that come into contact with such chemicals. These deposits cannot be removed completely from the components, even by flushing. It is only possible to service the refrigerant circuit by replacing all the components which come in contact with this material.

1. Refer to «REFRIGERANT CIRCUIT, TRACING LEAKS USING ELECTRONIC LEAK DETECTOR V.A.G 1796»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__refrigerant-circuit-tracing-leaks-using-electronic) .
2. Refer to «LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__leak-detection-on-refrigerant-circuit-using) .
3. Refer to «FINDING LEAKS USING VACUUM TEST WITH A/C SERVICE STATION OR WITH NITROGEN PRESSURE TESTING»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__finding-leaks-using-vacuum-test-with)

REFRIGERANT CIRCUIT, TRACING LEAKS USING ELECTRONIC LEAK DETECTOR V.A.G 1796

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

All vehicles

Note. The various refrigerants have differing molecular compositions. The sensors for the electronic leak detecting devices are set up to detect these molecules. If an electronic leak detection device is used, which is not specifically designed to detect refrigerant R134a, it will not respond to the refrigerant R134a or until a larger refrigerant concentration is in the area of the leak. Depending on the version of the A/C system, a leak on the evaporator can be determined by holding the test probe for the leak detection device above the connection for the glove compartment fan in the A/C unit or by holding the test probe on an open connection for the A/C system condensation water hose with the condensation water hose removed.

Perform a leak detection test to locate the leak while the refrigerant circuit is completely empty

Evacuate the refrigerant circuit with the A/C service station. Refer to EVACUATING REFRIGERANT CIRCUIT .

Note. If a larger leak is found during evacuation, find and it and repair it as described. Refer to EVACUATING REFRIGERANT CIRCUIT . If no leak is found during evacuation or there is a leak that is so small that the location cannot be found with the vacuum test, proceed as follows.

Refill the refrigerant circuit with approximately 100 Grams of refrigerant and perform the leak test in the same way as for a refrigerant circuit that is filled with refrigerant PERFORM A LEAK DETECTION TEST FOR A REFRIGERANT CIRCUIT THAT IS FILLED WITH REFRIGERANT .

PERFORM A LEAK DETECTION TEST FOR A REFRIGERANT CIRCUIT THAT IS FILLED WITH REFRIGERANT

Switch off ignition.

Start up leak detector in line with relevant operating instructions.

Always hold test probe beneath suspected leak.

Scheme 315

Depending on the model, leak detection is indicated by an increase in clicking rate or a warning tone (refer to operating instructions for leak detector).

Note. Currents of air quickly disperse refrigerant gas. Draughts must therefore be avoided during leak detection. Refrigerant gas is heavier than air and will escape.

LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201

Special tools and workshop equipment required

1. Leak Detection System VAS 6201
2. Hand Pump With Low Pressure Hose VAS 6201/1
3. Cartridge VAS 6201/2
4. Cleaning Agent VAS 6201/3
5. UV Leak Detection Lamp VAS 6201/4
6. UV-Absorbing Safety Goggles VAS 6201/6
7. Sticker VAS 6201/7
8. Filler Tube -- VAS 6201/8
9. Protective Gloves VAS 6201/9

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

All vehicles

Note. Certain leaks cannot or only with difficulty be found using an electric leak detection unit. Leak detection can be performed using leak detection system VAS 6201 for determining these leaks. Refrigerant and refrigerant oil escape when there is a leak in the refrigerant circuit. Generally, this oil remains in the vicinity of the leaking area. A small amount of fluorescent fluid must be added into refrigerant circuit so that this oil becomes visible under UV light. This fluid (PAG oil with an additive that lights up under UV light) is added into the refrigerant circuit and distributes itself with the refrigerant oil when the A/C system is switched on. A/C system must be operated for a minimum of 60 min. so that the additive distributes itself in the entire refrigerant circuit (compressor must be running). Depending on the size of the leak, it may become visible under UV light within that time. Refrigerant oil with additive that lights up under UV-light can be added directly with an open circuit or be pumped into a filled circuit via service connection on the low pressure side using hand pump VAS6201/1 (from leak detection system VAS 6201). If the leak detection additive is added to a filled refrigerant circuit via service connection on the low pressure side, a small amount of a UV-leak detection additive remains in the service connection. Carefully remove this residual amount so a leaking area is not detected erroneously upon a later leak detection. If a component in which UV-leak detection additive has been added is being replaced on a circuit, always clean connection areas to other components thoroughly after assembling refrigerant circuit. This UV-leak detection additive residue may occur erroneously as leaking areas during later leak detection. Refrigerant oil and with it UV-leak detection additive reaches into service station when evacuating a refrigerant circuit. Refrigerant oil is separated from refrigerant in oil collector of service station and removed from service station via draining device. The refrigerant oil drained off must not be poured back in. It must be replaced with new refrigerant oil. If leak detection fluid was filled already in a refrigerant circuit for an earlier repair, note the following: only add new leak detection additive if the refrigerant oil will be replaced. If only a portion of refrigerant oil was replaced, only top-off with a corresponding amount of leak detection fluid as well. For example, if 100 ml of refrigerant oil was replaced in a vehicle with 250 ml, add only 1 ml (cm 3 ) of UV-leak detection additive. Certain materials and their connections (for example, oxidation products on aluminum components, corrosion protection growth, etc.) also light up under UV-light. Depending on the version of the A/C Service Station, stop UV-leak additive can also be added directly at the top. Refer to the Operating Instructions that come with the A/C Service Station.

To prevent more refrigerant than is necessary for the leak test from venting into the air, proceed as follows with the refrigerant circuit completely empty

Evacuate the refrigerant circuit with the A/C service station. Refer to EVACUATING REFRIGERANT CIRCUIT .

Note. If a larger leak is found during evacuation, find and it and repair it as described. Refer to FINDING LEAKS USING VACUUM TEST WITH A/C SERVICE STATION OR WITH NITROGEN PRESSURE TESTING and EVACUATING REFRIGERANT CIRCUIT . The UV-leak detection additive can also be filled in a filled or open refrigerant circuit with the VAS 6201, refer to LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201 .

If no leak is found during evacuation or there is a leak that is so small that the location cannot be found, proceed as follows.

1. Fill the UV-leak detection additive with the A/C Service Station in the refrigerant circuit, refer to «FILL THE UV-LEAK DETECTION ADDITIVE WITH THE A/C SERVICE STATION IN THE REFRIGERANT CIRCUIT»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__fill-the-uv-leak-detection-additive-with) .
2. Add UV-leak detection additive using the VAS 6201 in the refrigerant circuit «LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__leak-detection-on-refrigerant-circuit-using) .

FILL THE UV-LEAK DETECTION ADDITIVE WITH THE A/C SERVICE STATION IN THE REFRIGERANT CIRCUIT

Add UV-leak detection additive and in the designated quantities using the A/C Service Station in the refrigerant circuit. Refer to REFRIGERANT R134A CAPACITIES .

Note. Add 2.5 + / - 0.5 cm 3 of UV-leak detection additive for a refrigerant circuit with a refrigerant capacity of 100 to 150 cm 3 with the - VAS 6201/1- for the VAS 6201. If the refrigerant oil capacity in the refrigerant circuit is greater, more UV-leak detection additive must be added (that is 5.0 + / - 0.5 cm 3 for a refrigerant circuit with a refrigerant oil capacity of 250cm 3 . When adding the UV-leak detection additive with the A/C Service Station, consult the corresponding Owner's Manual as the required amount may vary. For the respective refrigerant oil quantities in the refrigerant circuit, refer to REFRIGERANT OIL CAPACITIES .

Apply a label near the service connection stating that UV-leak detection additive was added to the refrigerant circuit.

Start the A/C system.

Note. A/C system must be operated for a minimum of 60 minutes so that the additive distributes itself in the entire refrigerant circuit (compressor must be running). Depending on the size of the leak, it may become visible under UV light within that time. Depending on the size and location of the leak, it can now last up to several days until enough refrigerant oil with UV-leak detection additive flows out to determine definitely the leaking area.

Find the leak in the refrigerant circuit with the UV lamp VAS 6196/4 DETECTING LEAKS ON REFRIGERANT CIRCUIT USING UV LAMP VAS 6196/4 .

ADD UV-LEAK DETECTION ADDITIVE USING THE VAS 6201 IN THE REFRIGERANT CIRCUIT

Note. Described in the following are instructions for how to pour the UV-leak detection additive into the refrigerant circuit using the - VAS 6201/1-. If the UV-leak detection additive is added to the refrigerant circuit with the help of other tools (that is with the A/C Service Station) read the applicable operating instructions. Found here is the quantity of UV-leak detection additive required to be added for a refrigerant circuit with a refrigerant oil quantity of 100 to 150cm 3 using the - VAS 6201- (2.5 + / - 0.5 cm 3 ). If the refrigerant oil capacity in the refrigerant circuit is greater, more UV-leak detection additive must be added (that is 5.0 + / - 0.5 cm 3 for a refrigerant circuit with a refrigerant oil capacity of 250cm 3 . For the respective refrigerant oil capacity in the refrigerant circuit, refer to REFRIGERANT OIL CAPACITIES . If the UV-leak detection additive is added to the refrigerant circuit with the help of other tools (such as with the A/C Service Station) read the applicable operating instructions and designated quantities of UV-leak detection additive.

Scheme 316

The cartridge -A- contains 15.4 ml of UV-leak detection additive (one unit -B- corresponds to 2.5 ml).

Assemble - VAS 6201- item -1- with cartridge item -2- - VAS 6201/2-.

Scheme 317

Insert the filler tube VAS 6201/8 in the hand pump, refer to item -7- under LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201 .

Open hand pump service valve.

Note. UV-Leak detection additive is best added to the empty refrigerant circuit via a Service connection or via an opened connection. If the refrigerant circuit is empty, then it is better to add the UV-leak detection additive at an open connection (for example, when the connection is already open). This way no UV-leak detection additive will remain back in the Service connection and then the connection does not need to cleaned.

1. Add the UV-leak detector additive to the refrigerant circuit at a Service connection.
2. Add the UV-leak detector additive to the refrigerant circuit at an opened connection «ADD THE UV-LEAK DETECTOR ADDITIVE TO THE REFRIGERANT CIRCUIT AT AN OPENED CONNECTION»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant) .

Scheme 318

Open an easily accessible connection point on refrigerant circuit

Cover area around connection point with foil or absorbent paper.

Hold tube upwards.

Tighten the toggle on the hand pump until the UV-leak detection additive comes out of the tube.

Add 2.5 + / - 0.5 ml (Milliliter = cm 3 ) of UV-leak detection additive into the refrigerant circuit (for a refrigerant circuit with a refrigerant oil capacity from 100 to 150 cm 3 ).

Note. If UV-leak detection additive was filled already in a refrigerant circuit for an earlier repair, note the following: only add new UV-leak detection additive if the refrigerant oil will be replaced. If only a portion of the refrigerant oil was replaced, only add a proportionate amount of the UV-leak detection additive. For example, if 100 ml of refrigerant oil was replaced in a vehicle with 250 ml, add only 2 ml (cm 3 ) of UV-leak detection additive.

Replace O-ring seal at open connection.

Assemble refrigerant circuit

Affix a sticker in the area of the service connection with the note that leak detection fluid was added to this refrigerant circuit.

Evacuate and recharge refrigerant circuit according to specification. Refer to EVACUATING REFRIGERANT CIRCUIT and CHARGING REFRIGERANT CIRCUIT .

Start the A/C system.

Note. A/C system must be operated for a minimum of 60 min. so that the additive distributes itself in the entire refrigerant circuit (compressor must be running). Depending on the size of the leak, it may become visible under UV light within that time. Depending on the size and location of the leak, it can now last up to several days until enough refrigerant oil with additive flows out to determine definitely the leaking area.

Find the leak in the refrigerant circuit with the UV lamp VAS 6196/4, refer to DETECTING LEAKS ON REFRIGERANT CIRCUIT USING UV LAMP VAS 6196/4 .

FILLING UV-LEAK DETECTION ADDITIVE WHEN THE REFRIGERANT CIRCUIT IS FULL

Note. If leak detection fluid was filled already in a refrigerant circuit for an earlier repair, note the following: only add new leak detection additive if the refrigerant oil will be replaced. If only a portion of refrigerant oil was replaced, only top-off with a corresponding amount of leak detection fluid as well. For example, if 100 ml of refrigerant oil was replaced in a vehicle with 250 ml, add only 1 ml (cm 3 ) of UV-leak detection additive. A small quantity of UV-leak detection additive remains in the service connection. Carefully remove this residual amount so a leaking area is not detected erroneously upon a later leak detection.

The cartridge -A- contains 15.4 ml of UV-leak detection additive (one unit -B- corresponds to 2.5 ml).

Switch off ignition.

Remove sealing cap from service connection of low pressure side in refrigerant circuit.

Assemble - VAS 6201/1- item -1- with cartridge item -2- - VAS 6201/2-.

Insert tube - VAS 6201/8- into service coupling and open service coupling by screwing in handwheel. Hold the hose upward and tighten the handle of the hand pump just enough until the UV-leak detection additive starts to emerge from the tube, refer to item -7- under LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201 .

Note. Make sure hand pump hose is completely filled with refrigerant.

Close service coupling and remove tube from locking mechanism.

Cover area around service connection on vehicle with foil or absorbent paper.

Scheme 319

Connect filler unit to refrigerant circuit service connection on vehicle.

Open service connection by screwing in handwheel.

Turn the hand pump handle to add 2.5 + /- 0.5 ml (Milliliter= cm 3 ) UV-leak detection additive in the refrigerant circuit (for a refrigerant circuit with a refrigerant oil quantity from 100 to 150 cm 3 ).

Remove filling device from service connection.

Scheme 320

Remove the rest of the UV-leak detection additive from the service connection, for example with absorbent paper.

Seal service connection with sealing cap.

If necessary, clean area around service connection using cleaning agents.

Affix sticker next to service connection with the note that leak detection fluid was added to this refrigerant circuit.

Start the A/C system.

Note. A/C system must be operated for a minimum of 60 min. so that the additive distributes itself in the entire refrigerant circuit (compressor must be running). Depending on the size of the leak, it may become visible under UV light within that time. Depending on the size and location of the leak, it can now last up to several days until enough refrigerant oil with additive flows out to determine definitely the leaking area.

Find the leak in the refrigerant circuit with the UV lamp VAS 6196/4 DETECTING LEAKS ON REFRIGERANT CIRCUIT USING UV LAMP VAS 6196/4 .

DETECTING LEAKS ON REFRIGERANT CIRCUIT USING UV LAMP VAS 6196/4

Note. After adding the UV-leak detection additive, the A/C system must be operated for a minimum of 60 min. so that the additive distributes itself in the entire refrigerant circuit (compressor must be running). Depending on the size of the leak, it may become visible under UV light within that time. Depending on the size and location of the leak, it can now last up to several days until enough refrigerant oil with additive flows out to determine definitely the leaking area. With leaks on evaporator, leak detection additive is possibly washed off with condensation and flows out via evaporator drain. Since the evaporator is not easily accessible on most vehicles, checking the evaporator drain may indicate if the evaporator is leaking. However, it is necessary for this purpose that leak detection additive has already been in the refrigerant circuit for a long period of time (such as a few days). Protective goggles do not serve as eye protection but rather it amplifies the illumination of UV-leak detection additive under UV-light. Depending on the accessibility of different components in the refrigerant circuit, it may be necessary to remove some vehicle components such as the bumper or air filter. Only a little refrigerant oil will get onto certain places on the refrigerant circuit when A/C is being used (for example, on the top cover of the fluid reservoir attached to the condenser on an Audi A8 from MY 10). If there is a leak at this spot, it may take longer until enough refrigerant with refrigerant oil and additive start to leak out, which then can be viewed under UV light. It may be useful to use an electronic leak detector at these locations to find a leak. Refer to REFRIGERANT CIRCUIT, TRACING LEAKS USING ELECTRONIC LEAK DETECTOR V.A.G 1796

Move vehicle into a slightly darker area of the workshop (with daylight or bright lighting the effect of the UV light is diminished).

Scheme 321

Check the accessibility of the various components in the refrigerant circuit and remove any components in the area that block access to the refrigerant circuit such as noise insulation and the bumper.

Wear protective eyewear to protect the eyes.

Connect the UV-lamp to a 12 volt battery (vehicle battery). Observe correct polarity of connections.

Switch on UV lamp and illuminate components of refrigerant circuit. Locations where refrigerant, refrigerant oil and UV-leak detection additive has leaked out light up under fluorescent UV light.

FINDING LEAKS USING VACUUM TEST WITH A/C SERVICE STATION OR WITH NITROGEN PRESSURE TESTING

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

All vehicles

Switch off the ignition.

1. Finding Leaks Using Vacuum Test with A/C Service Station or with Nitrogen Pressure Testing, refer to «EVACUATING REFRIGERANT CIRCUIT»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-general-information-avant__evacuating-refrigerant-circuit) .

Note. Small leaks (less than 100 g of refrigerant seepage per year) are not often detected with the vacuum test or with the nitrogen pressure test. The amount of air coming in or the amount of nitrogen seeping out is too little to locate the position based on noise. Also, leaks on the refrigerant circuit that are greater than 100 g of refrigerant seepage each year are not always detectable with the vacuum test or with the nitrogen pressure test, depending on the ambient conditions (ambient noise, leak location etc.). The incoming air and the quantity of nitrogen flowing out is currently too small to detect any noise and locate the faulty location. Larger leaks on the refrigerant circuit (such as an impact from a rock on the condenser, greater than 100 g of seeping refrigerant per year) can be detected from noise, using the vacuum test or the nitrogen pressure test. Refer to EVACUATING REFRIGERANT CIRCUIT .

REFRIGERANT CIRCUIT CONCERNS

1. Electrical system, vacuum system and air duct fault-finding has not revealed any faults. Refer to Guided Fault Finding for the A/C system using the Vehicle Diagnostic Tester and «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) .

1. The OBD/Guided Fault Finding for the A/C System with Vehicle Diagnostic Tester cannot detect a fault, the A/C compressor shut off condition is not displayed in the measured values block (only on vehicles with OBD "A/C System"). Refer to «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) or "Guided Fault Finding" using the Vehicle Diagnostic Tester.

Note. For all complaints marked *, refer to PRESSURES, CHECKING . If a malfunction occurs at only one evaporator in vehicles with two evaporators, also check pressures in the refrigerant circuit. Observe test requirements. Refer to REFRIGERANT CIRCUIT CONCERNS .

1. Total cooling system failure.*
2. Insufficient cooling performance at all vehicles speeds or engine speeds.*
3. None or insufficient cooling after driving a few miles.* *
4. No cooling or insufficient cooling at one or both evaporator(s) (on vehicles with two evaporators).* *
5. Compressor, A/C clutch -N25- or A/C compressor regulator valve -N280- shut off by pressure switch (for example, -F73-, -F118-, -F129- -F129- or by A/C Control Head -E87- or Climatronic Control Module -J255-) due to excessive or inadequate pressure. *
6. None or sharp decrease in fresh-air supply after driving several miles (evaporator iced up).* *

From these, the following complaints may also occur

The A/C Compressor Makes Noises

Tighten compressor securing bolts and compressor bracket using a torque wrench.

Check routing of refrigerant pipes; they must not touch other components and must not be subject to strain (align if necessary).

Noise (Refrigerant Hammer) Occurring Immediately After Switching On Air Conditioner and/or When Cornering Or Braking

Discharge, evacuate and charge refrigerant circuit (too much refrigerant in circuit).

Note. Too much refrigerant oil in the circuit could also cause this problem. This could occur if the amount of refrigerant oil was not adjusted when replacing the A/C compressor.

Water Sprays Out Of Vents (In Dash Panel Or Footwell) Although Air Conditioning System Is Otherwise Functioning Properly

Check proper routing of condensate drain; it must not be crushed or kinked.

Check condensation drain valve, it must not be clogged by wax or underbody sealant and must close properly.

Check plenum chamber cover; it must not be damaged and must be properly installed (to stop water running into evaporator).

Check water drains in plenum chamber; they must not be blocked (for example, by leaves).

GENERAL INFORMATION

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system, HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work in the vicinity of high voltage components, perform a visual inspection of the high voltage components and cables for damages. Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES and follow the warnings when working on the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work on the high voltage components, disable the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES and read and follow the high voltage electrical system general warnings in HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

Note. Working on the refrigerant circuit with the A/C service station usually requires, although not necessary, the high voltage system to be disabled.

Disable the high voltage system

Note. Disable the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - Disable the high voltage system (Rep.Gr. 93)

Restart the high voltage system

Note. Restart the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - High voltage restart (Rep.Gr. 93)

Charge the vehicle battery using the VAS 5903 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to DIAGNOSIS AND TESTING and GENERAL INFORMATION

Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.

Note. Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active. The ready mode is displayed in the instrument cluster control module -J285- above the "powermeter". Refer to the Owners Manual. Activate and deactivate the ready mode. Refer to the Owners Manual (consult the display in the instrument cluster control module).

Vehicles with Start/Stop System

All vehicles

1. Refrigerant circuit, checking pressure with service station, refer to «CHECKING PRESSURE WITH SERVICE STATION»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressure-with-service-station) .
2. Checking pressures for vehicles with restrictor and accumulator (with internally regulated compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-and-accumulator) .
3. Checking pressures on vehicles with expansion valve and fluid reservoir (with internally regulated compressor), refer to «CHECKING PRESSURES WITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-expansion-valve-and) .
4. Checking pressures for vehicles with restrictor, reservoir and A/C compressor regulator valve -N280- (externally regulated A/C compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-reservoir-and) .
5. Checking pressures on vehicles with restrictor, accumulator and A/C compressor regulator valve -N280- (externally regulated compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-accumulator-and) .
6. Inspect the pressures for vehicles with an electrically driven A/C compressor (vehicles with hybrid drive). Refer to «SPECIFIED VALUES FOR HYBRID REFRIGERANT CIRCUIT PRESSURES»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__specified-values-for-hybrid-refrigerant-circuit) .

CHECKING PRESSURE WITH SERVICE STATION

Note. All test conditions marked * are vehicle-specific and are described in the Repair Information for the relevant vehicle. Check cooling performance. Connections with valve and service connections for measurement and testing, refer to Diagnosis and Testing (vehicle-specific repair information). Depending on the A/C compressor version, there may be a valve installed on the high pressure side of the A/C compressor, which prevents the liquid refrigerant from flowing back into the compressor once the A/C is turned off. If an A/C compressor with this valve is installed in a vehicle with a refrigerant circuit having an expansion valve, then it may take some time until the pressure in the high pressure side decreases (the expansion is cold and the pressure in the low pressure side quickly increases after it is turned off, the expansion valve closes and the refrigerant flows slowly into the low pressure side). If the A/C compressor is switched on, the pressure on the low pressure side goes down, the expansion valve open and the refrigerant can flow of the low pressure side.

Under certain operating conditions, residual moisture in refrigerant circuit can lead to an ice build-up at compressor regulator valve. A/C compressor control is reduced by this ice build-up, evaporator is cooled too intensely and freezes. The freeze-up of the evaporator can be the cause for the following customer complaints

1. After a long drive, A/C system repeatedly or sporadically fails (no cooling or heating performance), after switching off vehicle and after a short time, A/C function is OK again.
2. After a long drive, windows fog up from inside, windows are also not cleared by pressing the Defrost button, after switching off vehicle and after a short time, A/C function is OK again.

Corrective Action

On vehicles as of model year 2001 equipped with a compressor with A/C compressor regulator valve -N280-, check measured value of evaporator outflow temperature Evaporator vent temperature sensor -G263- (via function "Read measuring value block"). Is the measured value from the sensor below the operating condition described by the customer (at a temperature above 0° C (32 °F), longer when it is lower than 0° C (32 °F) although the A/C compressor regulator valve is not currently activated) or too high (above 10° C (50 °F) even though the A/C is working correctly). An incorrect measured value can cause the evaporator to ice up. Refer to the Vehicle Diagnostic Tester("OBD" or "Guided Fault Finding for the A/C system") and Diagnosis and Testing (vehicle-specific repair information).

If the vehicle does have an Evaporator vent temperature sensor -G263-, check the "Lo temperature" for driver and passenger side, 4 or 5 bars for fresh air blower RPM, air outlet in footwell and fresh air operation under operating conditions specified by customer, for example, using the Footwell vent temperature sensor -G192-. If measured value of sensor is too low (at ambient temperature above 0 °C (32 °F), colder than 0 °C (32 °F) for a long period of time).

Check refrigerant line from evaporator to accumulator (thick tube, low pressure side) with engine running. If this line is thickly iced-up when complaint occurs (a thin layer of ice is permitted), this also indicates that the temperature in the evaporator is too low.

Discharge refrigerant circuit, replace accumulator or fluid reservoir with dryer and evacuate refrigerant circuit for a minimum of 3 hours.

1. Test requirements, refer to «TEST PREREQUISITES»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__test-prerequisites) .
2. Pressures, checking, refer to «PRESSURES, CHECKING»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant) .
3. Continuation of testing depending on design of refrigerant circuit, refer to «CONTINUATION OF TESTING DEPENDING ON DESIGN OF REFRIGERANT CIRCUIT»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__continuation-of-testing-depending-on-design) .

TEST PREREQUISITES

1. Radiator and condenser are clean (clean if necessary)
2. Thermal insulation at expansion valve OK and properly installed.*
3. Ribbed belt is OK and properly tensioned. Ribbed belt for A/C compressor and generator are OK and correctly tensioned.*
4. All air ducts, covers and seals OK and properly installed
5. Fault Finding did not detect any faults in the electrical system or in the vacuum system.* Refer to the Vehicle Diagnostic Tester("OBD" or "Guided Fault Finding for the A/C system") and «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

1. Air conditioner On Board Diagnostic (OBD) has not revealed any faults (with engine running and air conditioner switched on), no compressor shutoff criterion displayed in measured value block (vehicles with Air conditioner On Board Diagnostic only)* Refer to the Vehicle Diagnostic Tester("OBD" or "Guided Fault Finding for the A/C system") and «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

1. Air flow through dust and pollen filter not obstructed by dirt*
2. Air conditioner unit not drawing in secondary air at maximum fresh-air blower speed*, evaporator and heater not drawing in secondary air at maximum fresh-air blower speed*
3. Air doors in air conditioner unit, heater and evaporator reach end position*
4. Fresh-air intake ducts beneath hood and in passenger compartment as well as corresponding water drain valves OK*. Refer to «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

1. Engine is warm
2. Vehicle not exposed to direct sunlight. Refer to Refer to «Diagnosis and Testing»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#air-conditioning-avant) (vehicle-specific repair information).

1. Ambient temperature greater than 15° C (59 °F)
2. All instrument panel vents open

Start the engine.

Adjustment at Front A/C display control head -E87- or Climatronic Control Module -J255- (and Rear A/C display control head -E265- in vehicles with two A/C units)

Preselect "Auto" mode (A/C compressor on).

Set temperature pre-selector switch to LO for driver's side and front passenger's side (and left and right rear seats in vehicles with two A/C units).

Setting on heater controls

Press A/C button and Rec- or recirculated air button.

Turn rotary temperature control towards cold stop.

Set rotary fresh-air blower control to 4.

The following system test conditions should be met

1. One or more Radiator fan -V7- operated (at least speed 1)*

Note. For some versions, fan is switched on only once the pressure in refrigerant circuit has exceeded a specified value.

1. Fresh Air Blower -V2- (and Rear Fresh Air Blower -V80- in vehicles with two A/C units) running at maximum speed.
2. Recirculated/fresh-air door set to "Recirculated air mode" (within 1 minute, after starting vehicle, air-flow door is closed and recirculated-air door opened)*
3. The coolant shut-off valve closed.*
4. Valves of pump valve unit closed and no coolant circulation pump delivery*
5. Compressor is actually driven (A/C clutch -N25- operated, overload safeguard (if installed) not tripped)*

Note. The A/C compressor is driven by different components depending on the engine (belt or input shaft). The belt pulley or the drive unit has an overload protection to protect these components and the engine, if the A/C compressor is runs with resistance. Refer to Description and Operation (vehicle-specific repair information).

PRESSURES, CHECKING

1. Observe test requirements, refer to «TEST PREREQUISITES»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__test-prerequisites) .

Switch off the ignition.

Connecting service station. Refer to A/C SERVICE STATION .

Take pressure gauge readings (two possible results).

1. Pressure in refrigerant circuit lower than indicated in table
2. Pressure in refrigerant circuit in line with table or higher

Note. Temperature of refrigerant circuit components should be equal to ambient temperature. Pressure will deviate from values in table if individual components of refrigerant circuit are warmer or colder. At absolute pressure, 0 bar corresponds to absolute vacuum. Normal ambient pressure (positive pressure) corresponds to 1 bar absolute pressure. 0 pressure corresponds to an absolute pressure of one bar on most pressure gauges (indicated by -1 bar below 0). On vehicles with High pressure sensor -G65- or A/C pressure/temperature sensor -G395- for which measured pressure is displayed in measured value block, pressure measured should coincide using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C system") and Diagnosis and Testing (vehicle-specific repair information). Pressure is measured in different units: 1 MPa (mega Pascal) corresponds to 10 bar positive pressure or 145 psi, 1 bar absolute pressure corresponds to 0 bar positive pressure and thus to the ambient pressure (atmospheric pressure).

Pressure In Refrigerant Circuit Lower Than Indicated In Table

Not enough refrigerant in refrigerant circuit

Determine refrigerant circuit leaks. Refer to REFRIGERANT CIRCUIT, DETERMINING LEAKS .

Check pressure relief valve.

If pressure relief valve has responded

Check coolant fan activation.

Check refrigerant pipes and hoses for cross-section constrictions caused by inadequate bending radii.

Check refrigerant pipes and hoses for external damage.

If no fault is found, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Pressure In Refrigerant Circuit In Line With Table Or Higher

Start the engine.

Set air conditioning system to maximum cooling output.

Note. If the vehicle has a Compressor regulator valve -N280- control current can be read out in measured value block using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

If compressor is not driven with engine running or regulating valve is not actuated

Determine and eliminate cause, for example by checking air conditioner DTC memory.

Observe test conditions.

Check the A/C clutch -N25- voltage supply. If it is OK, repair the A/C clutch.

Check the actuation of the A/C compressor regulator valve -N280- using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

Note. If the low pressure switch was removed to connect the service station, bridge the electrical connections in the corresponding connector for the pressure measurement. A/C compressor is driven by the engine via A/C Clutch -N25-. The A/C compressor regulator valve -N280- is actuated by the Front A/C display control head -E87- or the Climatronic control module -J255-. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

CONTINUATION OF TESTING DEPENDING ON DESIGN OF REFRIGERANT CIRCUIT

1. Checking pressures for vehicles with restrictor and accumulator (with internally regulated compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-and-accumulator) .
2. Checking pressures on vehicles with expansion valve and fluid reservoir (with internally regulated compressor), refer to «CHECKING PRESSURES WITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-expansion-valve-and) .
3. Checking pressures for vehicles with restrictor, reservoir and A/C compressor regulator valve -N280- (externally regulated A/C compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-reservoir-and) .
4. Checking pressures on vehicles with restrictor, accumulator and A/C compressor regulator valve (externally regulated compressor), refer to «CHECKING PRESSURES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__checking-pressures-with-restrictor-accumulator-and) .

CHECKING PRESSURES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR

Note. Connecting service station. Refer to A/C SERVICE STATION . Observe test requirements. Refer to PRESSURES, CHECKING .

Refrigerant circuit, checking pressure with service station, refer to CHECKING PRESSURE WITH SERVICE STATION .

The pressures with the ignition turned off meet the specifications.

Start the engine.

Set engine speed to 2000 RPM.

Observe pressure gauge of service station.

Note. Switching pressures for refrigerant circuit switches are vehicle-specific. Connection with valve for low-pressure switch or at evaporator is only to be used for vehicles with no service connection on low-pressure side and inaccessible connection at compressor or accumulator (measurement accuracy). Applies only to certain vehicles, refer to Diagnosis and Testing (vehicle-specific repair information).

1. Specified values for the refrigerant circuit pressures, refer to «SPECIFIED VALUES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__specified-values-with-restrictor-and-accumulator) .

SPECIFIED VALUES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR

High-pressure side

Increasing from initial pressure (when connecting pressure gauges) to a maximum of 20 bar.

Low-pressure side

Decreasing from initial pressure (when connecting pressure gauges) to the value in the graph.

Scheme 322

A - High pressure (measured at service connection) in bar

B - Low pressure (measured at connection with valve at compressor or accumulator) in bar

C - Permissible tolerance range

D - Low pressure (measured at connection with valve for low-pressure switch or at service connection) in bar

E - Permissible tolerance range

Note. If no fault is found with this complaint, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Note. If problem involving moisture in refrigerant circuit only occurs after a lengthy operating period or only infrequently (low pressure drops below specification and evaporator ices up), it is sufficient to replace the dryer (adjust quantity of refrigerant oil). Refrigerant circuit is then to be evacuated for at least 3 hours. It is not initially necessary to clean the refrigerant circuit when this problem occurs since normally there is only a small quantity of moisture in the system which can be removed by lengthy evacuation (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Note. For the malfunction "high pressure normal, low pressure too low" With this malfunction, evaporator may ice up or the Low pressure switch -F73- turns off the A/C compressor, although quantity of refrigerant in circuit is OK. On the Audi 100, Audi A6 (up to model year 1997) and Audi V8, this fault may result in compressor being shut off by control head (if temperature at fresh-air blower drops below -3 °C (26 F)) Diagnosis and Testing .

Note. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit the correct quantity of refrigerant oil is filled into the circuit (flush with refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Refer to REFRIGERANT OIL CAPACITIES .

CHECKING PRESSURES WITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR

Note. Connecting service station. Refer to A/C SERVICE STATION . Observe test requirements. Refer to PRESSURES, CHECKING .

Refrigerant circuit, checking pressure with service station, refer to CHECKING PRESSURE WITH SERVICE STATION .

The pressures with the ignition turned off meet the specifications.

Start the engine.

Set engine speed to 2000 RPM.

Observe pressure gauge of service station.

Note. Switching pressures and design of refrigerant circuit switches are vehicle-specific. Pressures must be measured at service connections; component locations of these connections are vehicle-specific. Refer to Diagnosis and Testing (vehicle-specific repair information).

1. Specified values for the refrigerant circuit pressures, refer to «SPECIFIED VALUESWITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__specified-valueswith-expansion-valve-and-fluid) .

SPECIFIED VALUESWITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR

High-pressure side

Increasing from initial pressure (when connecting pressure gauges) to a maximum of 20 bar.

Low-pressure side

Decreasing from initial pressure (when connecting pressure gauges) to the value in the graph.

Scheme 323

A - High pressure in bar

B - Low pressure in bar

C - Permissible tolerance range

Note. If no malfunction can be found and air conditioner operation is not OK when test is repeated, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Note. If operation is not OK after cleaning refrigerant circuit (flushing with R134a or blowing through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ), expansion valve must be replaced.

Note. It is not initially necessary to clean the refrigerant circuit when this problem occurs since normally, there is only a small quantity of moisture in the system which can be removed by lengthy evacuation (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). If problem involving moisture in refrigerant circuit only occurs after a lengthy operating period or only infrequently (low pressure drops below specification and evaporator ices up), it is sufficient to replace the dryer (adjust quantity of refrigerant oil). Refrigerant circuit is then to be evacuated for at least 3 hours.

Note. If air conditioner operation is not OK when test is repeated, install old expansion valve, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Then replace A/C compressor and reservoir.

Note. If air conditioner operation is not OK when test is repeated, install old expansion valve, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Then replace A/C compressor and reservoir. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK.

Note. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit the correct quantity of refrigerant oil is filled into the circuit (flush with refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Refer to REFRIGERANT OIL CAPACITIES .

CHECKING PRESSURES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR

Note. Connecting service station. Refer to A/C SERVICE STATION . Observe test requirements. Refer to PRESSURES, CHECKING .

Refrigerant circuit, checking pressure with service station, refer to CHECKING PRESSURE WITH SERVICE STATION .

The pressures with the ignition turned off meet the specifications.

Start the engine.

Set engine speed to 2000 RPM.

Observe pressure gauge of service station.

Note. The switch pressures for the A/C compressor regulator valve -N280- and the Radiator fan -V7- are vehicle specific. Pressures must be measured at service connections; component locations of these connections are vehicle-specific. Refer to Diagnosis and Testing (vehicle-specific repair information).

1. Specified values for the refrigerant circuit pressures, refer to «SPECIFIED VALUES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__specified-values-with-restrictor-reservoir-and) .

SPECIFIED VALUES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR

High-pressure side

Increasing from initial pressure (when connecting pressure gauges) to 20 bar.

Low-pressure side

Decreasing from initial pressure (when connecting pressure gauges) to the value in the graph.

Scheme 324

A - Low pressure (measured at service connection) in bar absolute

B - Control current for A/C compressor regulator valve -N280- in amps

C - Permissible tolerance range

Note. If high cooling output is needed (for example, the outside temperature is very high, the blower speed is set on high but the engine RPMs are low), then the A/C compressor will not bring the pressure on the low pressure side to the value specified in the diagram -C- (for example, for a certain time after turning on the A/C). Compressor is actuated with maximum specified control current, however delivery volume is no longer sufficient at this engine speed to reduce pressure on low-pressure side to value in graph. To check the A/C compressor control under these conditions, for example, the fresh air blower is controlled only with approximately 40% of the maximum voltage, check the pressures at a lower fresh air blower speed using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C system") and Diagnosis and Testing (vehicle-specific repair information). Under unfavorable conditions (very high ambient temperatures, high humidity), pressure on high-pressure side may increase to maximum 29 bar. Control current -B- is displayed in measured value block of Front A/C display control head -E87- or Climatronic Control Module -J255-. The measured pressure from the High pressure sensor -G65- or from the A/C pressure/temperature sensor -G395- inside the refrigerant circuit pressure is displayed in the measured values block for the Front A/C display control head and the Climatronic control module -J255-. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information). Low pressure settles as a function of control current for A/C compressor regulator valve -N280- within compressor output range in tolerance range. Under unfavorable conditions (very high ambient temperatures, high humidity), compressor output may not always be sufficient to attain the specified value. If compressor capacity utilization is greater than 90%, pressure on low-pressure side may be in excess of tolerance range "C" shown in graph (compressor output no longer sufficient). The specified operating current for the regulator valve must be greater than 0.3 A in order to ensure reliable valve activation. At absolute pressure, 0 bar corresponds to absolute vacuum. Normal ambient pressure corresponds to 1 bar absolute pressure. 0 bar pressure corresponds to an absolute pressure of one bar on most pressure gauges (indicated by -1 bar below 0). In "maximum cooling output" setting, control current is regulated to approximately 0.65 (vehicle-specific up to 0.85A, displayed in measured value block) using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing or Air Conditioning (vehicle-specific repair information).

Note. If no fault is found with this complaint, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Note. It is not initially necessary to clean the refrigerant circuit when this problem occurs since normally there is only a small quantity of moisture in the system which can be removed by lengthy evacuation (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). If problem involving moisture in refrigerant circuit only occurs after a lengthy operating period or only infrequently (low pressure drops below specification and evaporator ices up), it is sufficient to replace the dryer (adjust quantity of refrigerant oil). Refrigerant circuit is then to be evacuated for at least 3 hours. Problem with Evaporator Vent Temperature Sensor -G263- can also cause icing-up of refrigerant circuit. If this problem is encountered, also pay attention to measured value of evaporator vent temperature sensor using Vehicle Diagnosis, Testing & Information System VAS5051B ("OBD" or "Guided Fault Finding for the A/C System" and Diagnosis and Testing (vehicle-specific repair information).

Note. Note the following if the malfunction is "high pressure normal, low pressure too low" : the evaporator could be iced over even though there is enough refrigerant in the circuit. Check the measured values from the Evaporator vent temperature sensor -G263- and the A/C compressor regulator valve -N280- actuation. If the measured value from the evaporator vent temperature sensor is incorrect, the evaporator may ice up or cooling output is not attained. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Air Conditioning (vehicle-specific repair information).

Note. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit the correct quantity of refrigerant oil is filled into the circuit (flushing with refrigerant R134a or blowing through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A , refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ) and refer to REFRIGERANT OIL CAPACITIES .

CHECKING PRESSURES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR

Note. Connecting service station. Refer to A/C SERVICE STATION . Observe test requirements. Refer to PRESSURES, CHECKING . If a malfunction occurs at only one evaporator in vehicles with two evaporators, also check pressures in the refrigerant circuit, are these OK? Check line connection between evaporator in question and exit of line connection at distribution point of refrigerant lines (for constriction). If no malfunction can be detected, discharge refrigerant circuit and charge it with the specified refrigerant quantity. Then check pressures and cooling performance of A/C system again; if the malfunction occurs again, replace the expansion valve which is prematurely switched by the malfunctioning evaporator. Refer to Diagnosis and Testing (vehicle-specific repair information).

Refrigerant circuit, checking pressure with service station, refer to CHECKING PRESSURE WITH SERVICE STATION .

The pressures with the ignition turned off meet the specifications.

Start the engine.

Set engine speed to 2000 RPM.

Observe pressure gauge of service station.

Note. Switching pressures for actuation of A/C compressor regulator valve -N280- and Radiator fan -V7- are vehicle-specific. Pressures must be measured at service connections; component locations of these connections are vehicle-specific. Refer to Diagnosis and Testing (vehicle-specific repair information).

1. Specified values for the refrigerant circuit pressures, refer to «SPECIFIED VALUES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__specified-values-with-restrictor-accumulator-and) .

SPECIFIED VALUES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR

High-pressure side

Increasing from initial pressure (when connecting pressure gauges) to a maximum of 20 bar.

Low pressure

Decreasing from initial pressure (when connecting pressure gauges) to the value in the graph.

A - Low pressure (measured at service connection) in bar absolute

B - Control current for A/C compressor regulator valve -N280- in amps

C - Permissible tolerance range (applicable to compressor capacity utilization of 10..0.90 %)

Note. If high cooling output is needed (for example, the outside temperature is very high, the blower speed it set on high but the engine RPMs are low), then the A/C compressor will not bring the pressure on the low pressure side to the value specified in the diagram -C- (for example, for a certain time after turning on the A/C). Compressor is actuated with maximum specified control current, however delivery volume is no longer sufficient at this engine speed to reduce pressure on low-pressure side to value in graph. To check the A/C compressor control under these conditions, for example, the fresh air blower is controlled only with approximately 40% of the maximum voltage, check the pressures at a lower fresh air blower speed. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C system") and Diagnosis and Testing (vehicle-specific repair information). Under unfavorable conditions (very high ambient temperatures, high humidity), pressure on high-pressure side may increase to maximum 29 bar. Control current -B- is displayed in measured value block of Front A/C display control head -E87-, Climatronic Control Module -J255-. High pressure measured by High Pressure Sensor -G65- or A/C Pressure/temperature Sensor -G395- is displayed in measured value block of Front A/C Control Head, Climatronic Control Module -J255-. Low pressure settles depending on control current for A/C Compressor Regulator Valve -N280- and control characteristic of expansion valve within compressor output range in tolerance range. Under unfavorable conditions (very high ambient temperatures, high humidity), compressor output may not always be sufficient to attain the specified value. If compressor capacity utilization is greater than 90%, pressure on low-pressure side may be in excess of tolerance range C shown in graph (compressor output no longer sufficient). The specified operating current for the A/C Compressor Regulator Valve must be greater than 0.3 A in order to ensure reliable regulator valve actuation. In "maximum cooling output" setting, control current for A/C Compressor Regulator Valve is regulated to approximately 0.65 A (up to 0.85 A). This measured value is vehicle-specific and displayed in measured value block. At absolute pressure, 0 bar corresponds to absolute vacuum. Normal ambient pressure corresponds to 1 bar absolute pressure. On the scales of most pressure gauges, 0 bar corresponds to an absolute pressure of 1 bar (can be seen from -1 bar mark below 0). Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

Note. If no fault is found with this complaint, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Check the measured values from the Evaporator vent temperature sensor -G263- and the A/C compressor regulator valve control. If measured value of Evaporator vent temperature sensor is not OK, evaporator may ice up or cooling output is not attained. If air conditioner operation is not OK when test is repeated after replacing expansion valve, install old expansion valve, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Then replace A/C compressor and reservoir. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK. If expansion valve is malfunctioning (permanently closed or does not open sufficiently), A/C compressor regulator valve is actuated to maximum output and low pressure drops to value in graph or below (compressor draws off refrigerant from low-pressure side). As refrigerant cannot flow via expansion valve, cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

Note. Make sure the A/C compressor (the A/C compressor shaft) is actually being driven by the belt pulley/drive unit. Refer to Diagnosis and Testing (vehicle-specific repair information). As of MY 12, certain engines and A/C compressors that in addition to the A/C compressor regulator valve, have an A/C clutch -N25- attached to the belt pulley. Make sure the A/C clutch really is being actuated and the A/C compressor (A/C compressor shaft) is being driven by the belt pulley. Refer to Diagnosis and Testing (vehicle-specific repair information).

Note. If the function of the air conditioning system is not OK when the test is repeated, replace expansion valve and receiver. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK. If expansion valve is malfunctioning (permanently closed or does not open sufficiently), A/C compressor regulator valve -N280- is actuated to maximum output and low pressure drops to value in graph or below (compressor draws off refrigerant from low-pressure side). As refrigerant cannot flow via expansion valve, cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information). If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit (flushing with refrigerant R134a or blowing through using compressed air and nitrogen the correct quantity of refrigerant oil is filled into the circuit, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ) and refer to REFRIGERANT OIL CAPACITIES .

Note. It is not initially necessary to clean the refrigerant circuit when this problem occurs since normally there is only a small quantity of moisture in the system which can be removed by lengthy evacuation (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). If problem involving moisture in refrigerant circuit only occurs after a lengthy operating period or only infrequently (low pressure drops below specification and evaporator ices up), it is sufficient to replace the dryer installed in receiver (adjust quantity of refrigerant oil). Refrigerant circuit is then to be evacuated for at least 3 hours. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK. Problem with Evaporator Vent Temperature Sensor -G263- can also cause icing-up of refrigerant circuit. If this problem is encountered, also pay attention to measured value of evaporator vent temperature sensor using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System" and Diagnosis and Testing (vehicle-specific repair information).

Note. For the malfunction "high pressure normal, low pressure too low" With this malfunction, evaporator may ice up, although quantity of refrigerant in circuit is OK. If the problem is with the A/C compressor regulator valve (regulator valve is not actuated but A/C compressor operates nevertheless), refrigerant circuit does not have to be cleaned (flush with refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). In this case, it is sufficient to replace the A/C compressor (observe quantity of refrigerant oil in A/C compressor). If expansion valve is malfunctioning (permanently closed or does not open sufficiently), A/C compressor regulator valve is actuated to maximum output and low pressure drops to value in graph or below (compressor draws off refrigerant from low-pressure side). As however refrigerant cannot flow via expansion valve, cooling output is not attained and high pressure may also not increase or only increase slightly due to the absence of energy conversion. Check the measured values from the Evaporator vent temperature sensor -G263- and the A/C compressor regulator valve control. If the measured value from the evaporator vent temperature sensor is incorrect, the evaporator may ice up or cooling output is not attained. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

Note. This fault may also be caused by too much refrigerant oil in the circuit. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If expansion valve is malfunctioning (permanently closed or does not open sufficiently), A/C compressor regulator valve is actuated to maximum output and low pressure drops to value in graph or below (compressor draws off refrigerant from low-pressure side). As however refrigerant cannot flow via expansion valve, cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Check using the Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C System") and Diagnosis and Testing (vehicle-specific repair information).

Note. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If expansion valve is malfunctioning (permanently open), evaporator temperature is no longer regulated such that only refrigerant in gaseous state exits from the evaporator. Under certain usage conditions, liquid droplets may then be drawn in by the compressor and cause noise (liquid cannot be compressed). If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit (flushing with refrigerant R134a or blowing through using compressed air and nitrogen the correct quantity of refrigerant oil is filled into the circuit, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ) and refer to REFRIGERANT OIL CAPACITIES .

SPECIFIED VALUES FOR HYBRID REFRIGERANT CIRCUIT PRESSURES

Refer to GENERAL INFORMATION .

Switch off the ignition.

1. Connecting service station, refer to «A/C SERVICE STATION»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-general-information-avant) .
2. Observe test requirements, refer to «PRESSURES, CHECKING»(/audi/a4/b8-2007-2012/remont/automatic-hvac-system/#general-technical-data-refrigerant-r134a-servicing-avant__pressures-checking) .

Note. If there is a complaint for only one of the evaporators for vehicles with two evaporators (one evaporator in the A/C system and one evaporator in the battery cooling module), check and see if the pressure in the refrigerant circuit is OK. check line connection between evaporator in question and exit of line connection at distribution point of refrigerant lines (for constriction). If no malfunction can be detected, discharge refrigerant circuit and charge it with the specified refrigerant quantity. Then check pressures and cooling performance of the A/C system again; if the malfunction occurs again, check / replace the following components: In case the complaint is only on the evaporator in the A/C system, check the hybrid battery refrigerant shut-off valve 1 -N516- (it is open when it is not in an active state and allows the refrigerant to flow through) and replace the expansion valve on the evaporator in the A/C system if no malfunction can be found on the hybrid battery refrigerant shut-off valve 1. If only the evaporator in the battery cooling module has a complaint, check the activation of the hybrid battery refrigerant shut-off valve 2 -N517- on the expansion valve on the evaporator in the battery cooling module (it is closed when it is not in an activated state and does not allow the refrigerant to flow through). Refer to Description and Operation (vehicle-specific Repair Information).

Refrigerant circuit, checking pressure with service station, refer to CHECKING PRESSURE WITH SERVICE STATION

The pressures with the ignition turned off meet the specifications.

Charge the vehicle battery using the VAS 5903 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to DIAGNOSIS AND TESTING and GENERAL INFORMATION .

Note. Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active. The engine must not be running when checking the pressures in the refrigerant circuit for vehicles with a high voltage system. The ready mode is displayed in the instrument cluster control module -J285- above the "powermeter". Refer to the Owners Manual. Activate the ready mode (and observe the display in the instrument cluster control module). Refer to the Owners Manual.

Activate the drive ready mode. Refer to the Owner's Manual.

Switch on the A/C.

Observe pressure gauge of service station.

Note. The activation of the electrically driven A/C compressor occurs from the vehicle electrical system, the engine RPM does not have any effect on the A/C cooling output. The A/C compressor will not activate at the maximum speed (the A/C compressor speed is limited to about 5000/min) specified (from approximately 8500/min) for a stopped or slow moving vehicles (until the vehicle reaches a speed of about 45km/h (28 mph)). The activation of the electrically driven A/C compressor can be monitored by the Guided Fault Finding. Refer to the Vehicle Diagnostic Tester. Measure the pressures in the service connections. The installation location for these connections is vehicle specific. Refer to Diagnosis and Testing (vehicle-specific Repair Information).

High-pressure side

Increasing from initial pressure (when connecting pressure gauges) to a maximum of 20 bar.

Low-pressure side

Decreasing from initial pressure (when connecting the pressure manometer) to a value between 1.5 and 2.3 bar absolute pressure (depending on the required cooling output).

A/C compressor speed

Depending on the required cooling output between 800 and 8600 /min (currently a maximum of 5000/min for parked vehicles).

Note. The temperature of the air according to the evaporator, the current A/C compressor speed and the pressure of refrigerant on the high pressure side are displayed as the measured value on the Climatronic control module -J255- A/C control head. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for A/C System and the Battery Controls. If a high cooling output is needed (for example, the outside temperature is very high and the blower speed it set on high), then the A/C compressor will not bring the pressure on the low pressure side to the required value specified (for example, for a certain time after turning on the A/C). The A/C compressor will not activate at the maximum speed (the A/C compressor speed is limited to about 5000/min) specified (from approximately 8500/min) for a stopped or slow moving vehicles (until the vehicle reaches a speed of about 45km/h (28 mph)). After a vehicle reaches a speed of more than approximately 45 km /h (28 mph), the limit for the maximum permissible A/C compressor speed is lifted. The A/C compressor power (the delivery volume) and a high fresh air blower speed (inefficient environmental conditions) is not always sufficient enough for a A/C compressor speed of 5000/min to lower the pressure on the low pressure side to the target value according to the evaporator. To check the A/C compressor control under these conditions, for example, the fresh air blower is controlled only with approximately 40% of the maximum voltage, check the pressures at a lower fresh air blower speed. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for A/C System and the Battery Controls and the Diagnosis and Testing (vehicle-specific Repair Information). Under unfavorable conditions (very high ambient temperatures, high humidity), pressure on high-pressure side may increase to maximum 29 bar. The target value of the A/C compressor speed is displayed as a measured value on the Climatronic control module control head. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for A/C System. The high pressure measured from the A/C pressure/temperature sensor -G395- is displayed as a measured value on the Climatronic control module A/C control head. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System. Low pressure settles depending on the A/C compressor speed and the control characteristic of the expansion valve within the compressor output range in tolerance range (1.5 through 2.3 bar positive pressure). The target speed for the A/C compressor must be greater than 1500 /min for this test. The target speed for the "maximum cooling output" should be regulated at approximately 4000 to 5000 /min. This value is vehicle-specific and is displayed as a measured value on the Climatronic control module A/C control head. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for A/C System and the Battery Regulator. At absolute pressure, 0 bar corresponds to absolute vacuum. Normal ambient pressure corresponds to 1 bar absolute pressure. On the scales of most pressure gauges, 0 bar corresponds to an absolute pressure of 1 bar (can be seen from -1 bar mark below 0). Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and Diagnosis and Testing (vehicle-specific Repair Information). If, for a vehicle with 2 evaporators (one in the A/C unit and one in the battery cooling module), the measured temperature on one of the evaporators corresponds to the target value or the target value falls short, but does not reach the required target value on the other evaporator, the following adjustment is performed: the battery regulation control module -J840- activates the electric A/C compressor with increased speed (thereby increasing the A/C cooling output and decreasing the pressure on the low pressure side as well as the evaporator temperature) via the electric drive power and control electronics -JX1- and the A/C compressor control module -J842-. If the target value falls short for the temperature of one of the evaporators, the battery regulation control module activates the hybrid battery refrigerant shut-off valve 1 -N516- or the hybrid battery refrigerant shut-off valve 2 -N517-, so that the evaporator which is too cold is no longer supplied with refrigerant. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System. Since the power for the evaporator in the battery cooling module is noticeably smaller than the power for the evaporator in the A/C system, the required target temperature may still potentially be reached in the battery cooling module with too little refrigerant in the refrigerant circuit, but the target temperature in the evaporator in the A/C system will no longer be attainable (even though the A/C compressor is activated with increased air conditioner speed).

Note. Read the supporting information SPECIFIED VALUES FOR HYBRID REFRIGERANT CIRCUIT PRESSURES

Note. If no fault is found with this complaint, clean refrigerant circuit (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). One of these complaints may arise due to a constriction or a blockage in the refrigerant circuit Check the measured values for the sensors for the evaporator vent temperature sensor -G263- and the temperature sensor before hybrid battery evaporator -G756- and the temperature sensor after hybrid battery evaporator -G757- as well as the activation of the A/C compressor via the A/C compressor control module -J842- from the battery regulation control module -J840- using the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Controls. If there is an error in the measured value for the evaporator vent temperature sensor for the temperature sensor before hybrid battery evaporator or the temperature sensor after hybrid battery evaporator problems may arise in the cooling output or the evaporator may ice-up. If air conditioner operation is not OK, such as when the test is repeated after replacing expansion valve, install the old expansion valve, clean refrigerant circuit (flush using the refrigerant R134a or blow through using the compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). Then replace the A/C compressor and reservoir/ dryer cartridge. With a malfunction on one of the temperature sensors, the evaporator may ice up even though the quantity of refrigerant in the circuit is OK. If the expansion valve in the evaporator in the A/C system or the hybrid battery refrigerant shut-off valve 1 is malfunctioning (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and low pressure drops to value in graph or below (compressor draws off refrigerant from low-pressure side). As the refrigerant cannot flow via the expansion valve, the cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Controls and Diagnosis and Testing (vehicle-specific Repair Information). The evaporator in the A/C system has considerably more output than the evaporator in the battery cooling module. The hybrid battery refrigerant shut-off valve 2 -N517- on the expansion valve in the battery cooling module is dependent on the method for cooling the traction battery -A2- (hybrid battery) and currently is activated by the battery regulation control module -J840- at a specific battery temperature, so that the absence of energy via the evaporator in the battery cooling module does not increase or only slightly increases. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Controls and Diagnosis and Testing .

Note. To cool the traction battery -A2- (hybrid battery), the hybrid battery refrigerant shut-off valve 2 is currently activated by the battery regulation control module -J840- after a specific battery temperature is reached. If the A/C system driver is not already activated at this time, the electrical A/C compressor -V470- is activated via the A/C compressor control module -J842- by the battery regulation control module. The temperature of the air in front of and behind the evaporator in the battery cooling module is distributed via the battery regulation control module. If it can be determined that there is insufficient cooling, the information will be saved in the battery regulation control module. Refer to Activation of the A/C compressor is malfunctioning. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System, the A/C Compressor and the Battery Controls The temperature of the air (as well as the cooling output of the evaporator) in the battery cooling module is distributed via the temperature sensor (currently it cannot be measured using a thermometer while operating) and may only be checked using the Guided Fault Finding. Refer to Activation of the A/C compressor is malfunctioning. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System, the A/C Compressor and the Battery Controls. For further information see SPECIFIED VALUES FOR HYBRID REFRIGERANT CIRCUIT PRESSURES

Note. If the function of the air conditioning system is not OK when the test is repeated, replace expansion valve and (and the hybrid battery refrigerant shut-off valve 1) the reservoir. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK. If the expansion valve in the evaporator in the A/C system or the hybrid battery refrigerant shut-off valve 1 is malfunctioning (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and the low pressure drops to the target value or below (compressor draws off refrigerant from low-pressure side). As the refrigerant cannot flow via the expansion valve (the hybrid battery refrigerant shut-off valve 1), if the cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Controls and Diagnosis and Testing (vehicle-specific Repair Information). If the expansion valve on the evaporator in the battery cooling module is defective (or if the functionality or the activation of the hybrid battery refrigerant shut-off valve 2 -N517- is defective), constantly closed or does not open enough, then the A/C compressor is likewise activated with the maximum output (the required temperatures in the battery cooling module are not attained). The pressure on the low pressure side only falls to the target value or lower at the same time that there is no cooling output required in the A/C system (the hybrid battery refrigerant shut-off valve 1 is activated and is closed). The A/C compressor removes the refrigerant from the low pressure side from both evaporators). Since, however, no refrigerant can flow over the expansion valve in the A/C system (the hybrid battery refrigerant shut-off valve 1) and the cooling output in the battery cooling module is not attained (there is a malfunction in the battery cooling module), the electrical A/C compressor will be activated with a higher speed. Since, however, none of the refrigerant can flow through, the pressure on the low pressure side decreases below the target value. In addition, the high pressure may never or only slightly increase, due to the absence of energy. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Controls and Diagnosis and Testing (vehicle-specific Repair Information). Since the power for the evaporator in the battery cooling module is noticeably smaller than the power for the evaporator in the A/C system, the required target temperature may still potentially be reached in the battery cooling module with too little refrigerant in the refrigerant circuit, but the target temperature in the evaporator in the A/C system will no longer be attainable (even though the A/C compressor is activated with increased air conditioner speed). If there is too much refrigerant oil in the circuit, the compressor must be drained (flushed) and the reservoir/ the dryer cartridge must be replaced. After cleaning the refrigerant circuit (flushing with refrigerant R134a or blowing through using compressed air and nitrogen the correct quantity of refrigerant oil is filled into the circuit (in the A/C compressor), refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ) and refer to REFRIGERANT OIL CAPACITIES .

Note. It is not initially necessary to clean the refrigerant circuit when this problem occurs since normally there is only a small quantity of moisture in the system which can be removed by lengthy evacuation (flush using refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). If problem involving moisture in refrigerant circuit only occurs after a lengthy operating period or only infrequently (low pressure drops below specification and evaporator ices up), it is sufficient to replace the dryer installed in receiver (adjust quantity of refrigerant oil). Refrigerant circuit is then to be evacuated for at least 3 hours. With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK. Likewise, the refrigerant circuit may become iced if there is a malfunction on the evaporator vent temperature sensor -G263- or / and on the temperature sensor after hybrid battery evaporator -G757-. Also note for this complaint, the measured value for the evaporator vent temperature sensor and for the temperature sensor after hybrid battery evaporator (for vehicles with a battery cooling module) using the Vehicle Diagnostic Tester in the Function "Guided Fault Finding" for the A/C System and Description and Operation (vehicle-specific Repair Information).

Note. For the malfunction "high pressure normal, low pressure too low" With this malfunction, evaporator may ice up, although quantity of refrigerant in circuit is OK. If there is a fault in the A/C compressor (the A/C compressor is activated by the A/C compressor control module -J842- at too high of a speed), it is not necessary to clean the refrigerant circuit (with refrigerant R134a or blow through it with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ). In this case, it is sufficient to replace the A/C compressor (observe quantity of refrigerant oil in A/C compressor). If the expansion valve (or one of the two expansion valves) is malfunctioning (permanently closed or does not open sufficiently), the A/C compressor is also actuated to maximum output and the pressure on the low pressure side drops to value in graph or below (compressor draws off refrigerant from the low-pressure side). Since the refrigerant cannot flow via the defective expansion valve, the cooling output in the downstream evaporator is not attained and high pressure may also not increase or only increase slightly due to the absence of energy. The A/C compressor may thereby be activated with a higher speed since the required cooling output is not attained in one of the evaporators. The same goes for the functionality and the activation of the hybrid battery refrigerant shut-off valve 1 -N516- or the hybrid battery refrigerant shut-off valve 2 -N517- if they are faulty. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and Diagnosis and Testing or Description and Operation (vehicle-specific Repair Information). Check the measured values for the evaporator vent temperature sensor -G263- (and the measured values for the temperature sensor before hybrid battery evaporator -G756- and the temperature sensor after hybrid battery evaporator -G757-) as well as the activation of the A/C compressor by the A/C compressor control module -J842-. If the measured values for the evaporator vent temperature sensor (or temperature sensor before hybrid battery evaporator, for the temperature sensor after hybrid battery evaporator) or the activation of the A/C compressor is defective, the evaporator may ice up or the requirements for the cooling output will not be attained. Refer to the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and Diagnosis and Testing .

Note. This fault may also be caused by too much refrigerant oil in the circuit. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If the expansion valve for the evaporator in the A/C system (or for the evaporator in the battery cooling module) is malfunctioning (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and the low pressure drops to the target value or below (compressor draws off refrigerant from low-pressure side). Since the refrigerant cannot flow via the expansion valve, the cooling output is not attained and high pressure may also not increase or only increase slightly due to the absence of energy. The same goes for the functionality and the activation of the hybrid battery refrigerant shut-off valve 1 -N516- or the hybrid battery refrigerant shut-off valve 2 -N517- if they are faulty. check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and Description and Operation .

Note. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. If for example, the expansion valve is malfunctioning (permanently open), evaporator temperature (in the A/C system) is no longer regulated such that only refrigerant in gaseous state exits from the evaporator. Under certain usage conditions, liquid droplets may then be drawn in by the compressor and cause noise (liquid cannot be compressed). If there is too much refrigerant oil in the circuit, the compressor must be drained and the accumulator must be replaced. After cleaning the refrigerant circuit (flush with refrigerant R134a REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A ), fill the refrigerant circuit with the correct quantity of refrigerant REFRIGERANT OIL CAPACITIES .

LEAKING OR DAMAGED COMPONENTS EXCEPT A/C COMPRESSOR, ACCUMULATOR OR RECEIVER - CIRCUIT EMPTY OF REFRIGERANT

The refrigerant circuit was completely empty (for example with larger leak or cracked hose)

Note. In the event of only a minor leak with slow escape of refrigerant (for example at a small leakage point), the amount of refrigerant oil lost and the amount of moisture penetrating is not sufficient to influence operation of the air conditioner. The operations marked * are only to be implemented in case of a major leak (for example following an accident).

Electrically driven A/C compressor

Remove malfunctioning component.

Remove the electrically driven A/C compressor and flush. Refer to ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL) .

Clean refrigerant circuit (flush with refrigerant R134a or blow through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN )*

Fill the A/C compressor or the refrigerant circuit completely to the specified capacity.

Mechanically driven A/C compressor

Remove malfunctioning component.

Remove A/C compressor.*

Remove the oil drain plug -B- / -D- from the A/C compressor -A-.*

Scheme 325

Note. There are different versions of the oil drain plug -B- / -D- and gasket -C- / -E- (depending on who is the A/C compressor manufacturer). Pay close attention to the tightening specification for the oil drain plug -B- / -D- (depending on the A/C compressor manufacturer and the oil drain plug version). Refer to Specifications (vehicle-specific repair information). A/C compressors made by Denso and Nippondenso have an oil drain plug -D- with a gasket already installed -E- ; always replace. A/C compressors made by Sanden or Zexel have an oil drain plug -D- with an O-ring already installed -E- ; always replace. To accelerate drainage of refrigerant oil, rotate compressor, for example, by way of clutch plate of A/C clutch for example. Drain the old refrigerant oil from the A/C compressor* (for disposing, refer to Audi-ServiceNet, HSO Environment).

All

Note. Then fill A/C compressor with quantity of fresh refrigerant oil corresponding to quantity of refrigerant oil in replacement A/C compressor. Refer to REFRIGERANT OIL CAPACITIES .* Use different refrigerant oils and quantities for the various compressors. Refer to REFRIGERANT OIL CAPACITIES . To ensure compressor lubrication on start-up, at least 80 cm 3 of refrigerant oil must be poured into the compressor, the remainder can be added for example to the new reservoir or receiver. Refer to REFRIGERANT OIL CAPACITIES . If dirt has penetrated into the compressor with the refrigerant circuit open (for example after an accident), compressor is to be replaced. Clean refrigerant circuit (flush with refrigerant R134a or blow through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN )*

Replace dryer cartridge, receiver* or accumulator* and restrictor.

Assemble, evacuate and recharge refrigerant circuit.

LEAKING OR DAMAGED COMPONENTS EXCEPT A/C COMPRESSOR, ACCUMULATOR OR RECEIVER - CIRCUIT CONTAINS REFRIGERANT

Refrigerant circuit still contains refrigerant (for example, with minor leak)

Discharge refrigerant circuit

Remove malfunctioning component, flush with compressed air, collect escaping refrigerant oil.

The new component is to be filled with the amount of refrigerant oil flushed out (positive 20 cm 3 for evaporator, positive 10 cm 3 for condenser, refrigerant pipes and refrigerant hoses) as fresh refrigerant oil fill.

Note. Workshop-specific instructions, refer to Audi ServiceNet, HSO Environment.

Replace restrictor.

Assemble, evacuate and charge refrigerant circuit.

COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT

Note. Cleaning refrigerant circuit means flushing it with refrigerant R134a or blowing through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

For example, in the event of external damage following an accident

Discharge refrigerant circuit

Remove A/C compressor.

Electrically drivenA/C compressor

Flush the defective electrically driven A/C compressor to remove the refrigerant oil (write down the quantity of refrigerant that was flushed out), refer to ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL) .

Note. If 75% of the refrigerant is flushed out of the defective A/C compressor, which corresponds with the quantity within the replacement A/C compressor, do not flush the replacement A/C compressor. If less than 60% of the noted refrigerant oil capacity is flushed out of the defective A/C compressor, the remaining refrigerant oil is found in the refrigerant circuit components. To avoid overfilling with refrigerant oil, flush the refrigerant circuit or the electrically driven A/C compressor.

Flush the refrigerant circuit or the new electrically driven A/C compressor to remove the refrigerant oil. Refer to ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL) .

Dispose of the refrigerant oil removed from the defective and the new A/C compressor / refrigerant circuit, refer to Audi-ServiceNet, HSO-Environmental Protection).

Note. The electrically driven A/C compressor is constructed in such a way that it must be flushed in order to remove the refrigerant oil (the refrigerant oil cannot be poured out by removing the draining plug as in the case for the mechanically driven A/C compressor, refer to ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL) .

Only fill the replacement A/C compressor with the amount of new refrigerant that corresponds with the amount removed (from the defective A/C compressor).

Note. If, for example, 70 cm 3 of refrigerant oil has been poured out of the defective A/C compressor and 220 cm 3 out of the replacement A/C compressor (a small quantity of refrigerant oil remains in the A/C compressor). Fill the A/C compressor to be installed with 70 cm 3 of refrigerant oil (use can be made of oil poured out of replacement A/C compressor). Use different refrigerant oils and quantities for the various compressors. Refer to REFRIGERANT OIL CAPACITIES . If a greater quantity of refrigerant oil (more than approximately 80 cm 3 ) has been poured out of the malfunctioning compressor, the remaining refrigerant oil can also be added to the evaporator or reservoir/receiver. Refer to REFRIGERANT OIL CAPACITIES .

Mechanically driven A/C compressor

Remove the drain plug from the A/C compressor (mechanically driven A/C compressor).

Note. Different versions of the oil drain plug and its seal (it can be either an O-ring or a gasket; always replace); refer to LEAKING OR DAMAGED COMPONENTS EXCEPT A/C COMPRESSOR, ACCUMULATOR OR RECEIVER - CIRCUIT EMPTY OF REFRIGERANT .

To accelerate drainage of refrigerant oil, rotate compressor, for example, by way of clutch plate of A/C clutch for example.

Drain the old refrigerant oil from the A/C compressor* (for disposing, refer to Audi-ServiceNet, HSO Environment).

Remove oil drain plug from replacement A/C compressor, pour out refrigerant oil and only add a quantity of fresh refrigerant oil equal to the amount poured out of the malfunctioning A/C compressor.

Note. If, for example, 70 cm 3 of refrigerant oil has been poured out of the defective A/C compressor and 220 cm 3 out of the replacement A/C compressor (a small quantity of refrigerant oil remains in the A/C compressor). Fill the A/C compressor to be installed with 70 cm 3 of refrigerant oil (use can be made of refrigerant poured out of replacement A/C compressor). Use different refrigerant oils and quantities for the various compressors. Refer to SPECIFICATIONS . If a greater quantity of refrigerant oil (more than approximately 80 cm 3 ) has been poured out of the malfunctioning compressor, the remaining refrigerant oil can also be added to the evaporator or reservoir/receiver SPECIFICATIONS .

All

Replace the restrictor (only if there is on in this refrigerant circuit).

Assemble, evacuate and charge refrigerant circuit.

COMPRESSOR, REPLACING DUE TO LEAKAGE OR INTERNAL DAMAGE

Vehicles with a high voltage system (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work in the vicinity of high voltage components, perform a visual inspection of the high voltage components and cables for damages. Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES and follow the warnings when working on the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

If it is necessary to perform work on the high voltage components, disable the high voltage system. Refer to HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES and read and follow the high voltage electrical system general warnings in HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES .

Note. Working on the refrigerant circuit with the A/C service station usually requires, although not necessary, the high voltage system to be disabled.

Disable the high voltage system

Note. Disable the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - Disable the high voltage system (Rep.Gr. 93)

Restart the high voltage system

Note. Restart the high voltage system: Connect the vehicle diagnosis tester Select the Guided Fault Finding mode Using the GO TO button, select the following menu commands Functions/Component selection Body Electrical system OBD-capable system 8C - Hybrid battery management -J840 8C - Hybrid battery management, functions 51 - High voltage restart (Rep.Gr. 93)

Charge the vehicle battery using the VAS 5903 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to DIAGNOSIS AND TESTING and GENERAL INFORMATION

Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.

Note. Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active. The ready mode is displayed in the instrument cluster control module -J285- above the "powermeter". Refer to the Owners Manual. Activate and deactivate the ready mode. Refer to the Owners Manual (consult the display in the instrument cluster control module).

Vehicles with Start/Stop System

All vehicles

For example, because of noise or no A/C compressor output

Discharge refrigerant circuit

Remove A/C compressor.

Clean refrigerant circuit (flush with refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Note. In the event of internal damage (compressor), check refrigerant hoses and condenser. If, for example, shavings have penetrated, clean refrigerant hoses and condenser (flush with refrigerant R134a or blow through using compressed air or nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ), Replace refrigerant hoses if necessary. In vehicles with two evaporators, the refrigerant oil quantity in refrigerant circuit may be greater than the quantity which is found in the replacement compressor, if necessary add the remaining refrigerant oil quantity to the refrigerant circuit. Refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN . Do not flush the refrigerant circuit if there is a fault in the electronics in the electronically driven A/C compressor (such as the A/C compressor control module -J842- is defective). In this case, replace the A/C compressor/ the refrigerant circuit without flushing it COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT .

Replace dryer cartridge, receiver or accumulator and restrictor.

Examine expansion valve for dirt or corrosion; replace if necessary

Assemble, evacuate and charge refrigerant circuit.

RECEIVER OR ACCUMULATOR AND RESTRICTOR, REPLACING AFTER CLEANING REFRIGERANT CIRCUIT

Note. Cleaning refrigerant circuit means flushing it with refrigerant R134a or blowing through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN .

For example, on account of ingress of moisture (refrigerant circuit open for lengthy period) or contamination

Discharge refrigerant circuit

Remove A/C compressor.

Rectify cause of trouble.

Clean refrigerant circuit (flush with refrigerant R134a or blow through using compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

Examine expansion valve for dirt or corrosion; replace if necessary

Electrically driven A/C compressor

Flush the old refrigerant oil out of A/C compressor. Refer to ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL) .

Mechanically driven A/C compressor

Remove oil drain plug from A/C compressor.

Note. Different versions of the oil drain plug and its seal (it can be either an O-ring or a gasket; always replace). Refer to LEAKING OR DAMAGED COMPONENTS EXCEPT A/C COMPRESSOR, ACCUMULATOR OR RECEIVER - CIRCUIT EMPTY OF REFRIGERANT .

To accelerate drainage of refrigerant oil, rotate compressor, for example by way of clutch plate of A/C clutch for example.

Pour old refrigerant oil out of A/C compressor.

Note. Dispose of the old refrigerant oil, refer to Audi ServiceNet, HSO Environment.

All A/C compressors

Then add to the compressor the new refrigerant oil quantity which matches the refrigerant oil quantity in the replacement compressor (or the specified refrigerant oil quantity in vehicles with two evaporators if necessary). Refer to REFRIGERANT OIL CAPACITIES .

Note. Use different refrigerant oils and quantities for the various compressors. Refer to REFRIGERANT OIL CAPACITIES . To ensure compressor lubrication on start-up, at least 80 cm 3 of refrigerant oil must be poured into the compressor, the remainder can be added for example to the new reservoir or receiver. Refer to REFRIGERANT OIL CAPACITIES . If dirt has penetrated into the compressor with the refrigerant circuit open (for example, after an accident), compressor is to be replaced. In vehicles with two evaporators, the refrigerant oil quantity in refrigerant circuit may be greater than the quantity which is found in the replacement compressor, if necessary add the remaining refrigerant oil quantity to the refrigerant circuit. Refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN .

Replace receiver or accumulator and restrictor.

Assemble, evacuate and charge refrigerant circuit.

RECEIVER OR ACCUMULATOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT

Note. Cleaning refrigerant circuit means flushing it with refrigerant R134a or blowing through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN .

For example, in the event of accident damage; no escape of refrigerant and no ingress of moisture and dirt into circuit

Discharge refrigerant circuit

Replace restrictor.

Remove receiver or accumulator.

Remove dirt from receiver or reservoir.

Weigh receiver or reservoir removed.

Add refrigerant oil to the reservoir until it is the same weight as the reservoir that was removed.

Install new receiver or reservoir.

Assemble, evacuate and charge refrigerant circuit.

DRYER CARTRIDGE AND DRYER BAG, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT

Note. Cleaning refrigerant circuit means flushing it with refrigerant R134a or blowing through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN .

For example, no escape of refrigerant and no entry of moisture and dirt into circuit.

Discharge refrigerant circuit.

Replace the dryer cartridge. Refer to Removal and Installation (vehicle-specific repair information).

Assemble, evacuate and charge refrigerant circuit.

COMMERCIALLY AVAILABLE TOOLS AND MATERIALS

Service station (this illustration shows, as example, V.A.G 1885. For currently available service stations, refer to Special Tools and Equipment Information).

Scheme 326

1. Procedure: the operations "testing, extraction (recycling), evacuation and charging" are to be performed in line with the relevant operating instructions.
2. The filters and dryers installed are to be replaced at the latest at the end of the period of use specified in the operating instructions and whenever the station has been drained (keep replacement filter to hand. Available from equipment manufacturer, refer to operating instructions.
3. Use can also be made of service stations not described here. Refer to Special Tools and Equipment Information.
4. Currently available service stations are equipped with a program for flushing the refrigerant circuit; the flushing equipment required for flushing is also included in delivery.

Note. This A/C service station has the following known units: charging cylinder, pressure gauge set, vacuum pump, shutoff valves and charging hoses. One quick-release coupling each (for service connections on high and low-pressure side) is included in the scope of delivery of this service station. Current vacuum display (LED) appears after pressing the Evacuate button again.

Leak Detector V.A.G 1796

Leak Detection System VAS 6201

Scheme 327

Puller for A/C Clutch V.A.G 1719 (for Zexel A/C Compressor)

Scheme 328

Adapter Set For Refrigerant Circuit R134a V.A.G 1785/1-10

Scheme 329

Adapter for cleaning refrigerant circuit (flush with refrigerant R134a or blow through with compressed air and nitrogen, refer to REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A and refer to REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN ).

A - 5/8"-18 UNF thread for conical seal

B - Union nut (for connection with O-ring) with thread

1. M 18x1.5 V.A.G 1785/1
2. M 20x1.5 V.A.G 1785/2
3. M 24x1.5 V.A.G 1785/3
4. M 28x1.5 V.A.G 1785/4

Adapter

Scheme 330

A - 5/8"-18 UNF thread for conical seal

B - Threaded connection for O-ring

1. M18 x 1.5 V.A.G 1785/5
2. M20 x 1.5 V.A.G 1785/6
3. M24 x 1.5 V.A.G 1785/7
4. M28 x 1.5 V.A.G 1785/8

Valve Adapter

Scheme 331

A - 5/8"-18 UNF thread for conical seal

B - Internal thread with valve opener

1. M10 x 1.25 V.A.G 1785/9 (for connections with valve on high-pressure side)
2. M10 x 1.5 V.A.G 1785/10 (for connections with valve on high-pressure side)

Note. A Schrader valve is screwed into connection -A-. A valve opener must be installed in the charging hose connection. Various adapters from adapter set are also part of the Adapter case for VW/Audi passenger cars VAS 6338/1

Adapter Set With Service Connection V.A.G 1786

Scheme 332

A - Adapter with union nut V.A.G 1786/1 (only for connections with small valve insert on low-pressure side)

B - Charging hose with union nut 5/8"-18 UNF (short version)

C - Adapter with service connection V.A.G 1786/2

Note. For connections with large valve insert (standard on Zexel / Valeo compressors, gradual change to small valve insert as of 10.94), use is to be made of adapter V.A.G 1785/10 (remove valve from adapter V.A.G 1785/10 or install valve opener in charging hose -B-). Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Socket InsertT10364

Scheme 333

Note. For removing and installing Service connections and valve units when the refrigerant circuit is empty.

Fin Comb

Scheme 334

Fill Hoses

Scheme 335

5/8"-18 UNF thread

Note. Use differently colored charging hoses (1800 mm long). Have valve opener and spare seals to hand. A charging hose in short version is also included in Adapter case for VW/Audi passenger cars VAS 6338/1.

Connection Piece For Refrigerant Cylinder With Seal, Quick-Release Coupling Connection Or Threaded Connection 5/8" - 18 UNF

Scheme 336

Valve Caps With Spare Seals (for 5/8"-18 UNF thread)

Scheme 337

Seals can also be used for charging hoses.

Note. Valve caps with spare seals are also included in Adapter case for VW/Audi passenger cars VAS 6338/1.

Pressure Gauge Set With Pressure Reducer For Nitrogen (Maximum Reducing Pressure: 15 bar).

Scheme 338

1. Pressure gauge set
2. Pressure hose (inner diameter 5 mm, length 2 m)
3. Nitrogen
4. Hose fitting

Note. For connection to adapter V.A.G 1785 with 5/8"-18 UNF thread

Quick-Release Coupling Adapter For Service Connections

Scheme 339

1. High-pressure side, nominal size 16 mm
2. Low-pressure side, nominal size 13 mm
3. 2x release tool (Sharan)

Note. This quick-release coupling is delivered with the service station.

IMPROVISED TOOLS

Charging Hose With Connection For Workshop Compressed-Air System

Scheme 340

A - Charging hose 5/8" - 18 UNF** (version with large inner diameter)

B - Connection for workshop compressed-air system ** (always use filter)

See also:
• Removal and Installation
• HYBRID VEHICLE HIGH VOLTAGE SYSTEM PROCEDURES
• PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES
• DIAGNOSIS AND TESTING
• GENERAL INFORMATION
• EVACUATING REFRIGERANT CIRCUIT
• CHARGING REFRIGERANT CIRCUIT
• A/C SERVICE STATION
• REFRIGERANT CIRCUIT FLUSHING WITH REFRIGERANT R134A
• REFRIGERANT CIRCUIT FLUSHING WITH COMPRESSED AIR AND NITROGEN
• ELECTRICALLY DRIVEN A/C COMPRESSOR, RINSING (REMOVE REFRIGERANT OIL)
• CAPACITIES, AUDI A1 (8X_) FROM MY 11
• CAPACITIES, AUDI A2 (8Z_) FROM MY 01
• CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999
• CAPACITIES, AUDI A3 (8P_) FROM MY 04
• CAPACITIES, AUDI TT (8J_) FROM MY 07
• CAPACITIES, AUDI 80 (8A_/8C_), AUDI COUPE (8B_) AND AUDI CABRIOLET (8G_), FROM MY 2002
• CAPACITIES, AUDI A4 (8D_), FROM MY 95
• CAPACITIES, A4 (8E_) 01 AND AUDI A4 CABRIOLET (8H_), FROM MY 03
• CAPACITIES, AUDI A4 (8K_) FROM MY 2008, AUDI A5 COUPE (8T_) FROM MY 2008, AUDI Q5 (8R_) FROM MY 2008, AUDI A5 CABRIOLET (8F_) FROM MY 2009 AND AUDI Q5 HYBRID (8R_) FROM 2011
• CAPACITIES, AUDI 100 AND AUDI A6 (4A_), FROM MY 98
• CAPACITIES, AUDI A6 (4B_) FROM MY 1998 AND AUDI ALLROAD (4B_) FROM MY 2005
• CAPACITIES, AUDI A6 (4F_), FROM MY 05
• CAPACITIES, AUDI A6 (4G_) FROM MY 11 AND AUDI A7 (4G_) FROM MY 11
• CAPACITIES, AUDI V8 (4C_) FROM MY 94
• CAPACITIES, AUDI A8 (4D_) FROM MY 94
• CAPACITIES, AUDI A8 (4E_) FROM MY 03
• CAPACITIES, AUDI A8 (4H_) FROM MY 10, AUDI A8 HYBRID (4H_) FROM 2012
• CAPACITIES, AUDI Q7 (4L_), FROM MY 06
• CAPACITIES, AUDI R8 (42_) FROM MY 08
• DETERMINING DIMENSIONS OF FLAT PIPES FROM CONDENSER
• STICKER FOR CAPACITY OF REFRIGERANT R134A
• DISTINGUISHING FEATURES
• DETERMINING DIMENSIONS OF FLAT PIPES FROM CONDENSER
• CAPACITIES, AUDI A6 (4B_) 98 AND AUDI ALLROAD FROM MY 05
• CAPACITIES, AUDI A8 (4H_) FROM 2010, AUDI A8 HYBRID (4H_) FROM 2012
• REFRIGERANT CIRCUIT, TRACING LEAKS USING ELECTRONIC LEAK DETECTOR V.A.G 1796
• LEAK DETECTION ON REFRIGERANT CIRCUIT USING LEAK DETECTION SYSTEM VAS 6201
• FINDING LEAKS USING VACUUM TEST WITH A/C SERVICE STATION OR WITH NITROGEN PRESSURE TESTING
• PERFORM A LEAK DETECTION TEST FOR A REFRIGERANT CIRCUIT THAT IS FILLED WITH REFRIGERANT
• FILL THE UV-LEAK DETECTION ADDITIVE WITH THE A/C SERVICE STATION IN THE REFRIGERANT CIRCUIT
• REFRIGERANT R134A CAPACITIES
• REFRIGERANT OIL CAPACITIES
• DETECTING LEAKS ON REFRIGERANT CIRCUIT USING UV LAMP VAS 6196/4
• PRESSURES, CHECKING
• REFRIGERANT CIRCUIT CONCERNS
• CHECKING PRESSURE WITH SERVICE STATION
• CHECKING PRESSURES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR
• CHECKING PRESSURES WITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR
• CHECKING PRESSURES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR
• CHECKING PRESSURES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR
• SPECIFIED VALUES FOR HYBRID REFRIGERANT CIRCUIT PRESSURES
• TEST PREREQUISITES
• CONTINUATION OF TESTING DEPENDING ON DESIGN OF REFRIGERANT CIRCUIT
• REFRIGERANT CIRCUIT, DETERMINING LEAKS
• SPECIFIED VALUES WITH RESTRICTOR AND ACCUMULATOR - INTERNALLY REGULATED COMPRESSOR
• SPECIFIED VALUESWITH EXPANSION VALVE AND FLUID RESERVOIR - INTERNALLY REGULATED COMPRESSOR
• SPECIFIED VALUES WITH RESTRICTOR, RESERVOIR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED A/C COMPRESSOR
• SPECIFIED VALUES WITH RESTRICTOR, ACCUMULATOR AND A/C COMPRESSOR REGULATOR VALVE - EXTERNALLY REGULATED COMPRESSOR
• GENERAL INFORMATION
• LEAKING OR DAMAGED COMPONENTS EXCEPT A/C COMPRESSOR, ACCUMULATOR OR RECEIVER - CIRCUIT EMPTY OF REFRIGERANT
• COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT