Air Conditioning: Other Audi A3 8P facelift

REFRIGERANT SAFETY PRECAUTIONS

The following safety measures should be observed for these refrigerants (additional guidelines apply in individual countries).

The assemblies and piping system of the air conditioner are filled with the following refrigerant

1.1.1.2 Tetrafluorethane (CF 3 -CH 2 F or CH 2 F-CF 3 )

Currently, this refrigerant is known under the following trade names R134a, H-FKW 134a, SUVA 134a and KLEA 134a (other trade names may be used in other countries).

If is necessary to open the refrigerant circuit during service work, discharge the refrigerant circuit first, refer to REFRIGERANT CIRCUIT, DRAINING . In doing so, the utmost care is to be taken to avoid contact with liquid refrigerant or refrigerant vapors. Should refrigerant nevertheless escape, avoid inhaling the resultant refrigerant/air mixture.

Extraction systems are therefore to be switched on and use made of both rubber gloves and protective goggles.

Reason

Intensive exposure to refrigerant on unprotected parts of the body will result in frostbite.

Should refrigerant come into contact with other parts of the body despite compliance with all the pertinent safety measures, these are similarly to be rinsed thoroughly in cold water without delay for at least 15 minutes.

Although refrigerant does not represent a fire hazard, smoking, welding, soldering and brazing are not permitted in areas exposed to refrigerant.

Reason

The high temperature of a naked flame or hot objects causes decomposition of refrigerant gas. Inhalation of the resultant toxic decomposition products leads to dry coughing and nausea.

REFRIGERANT CIRCUIT REPAIR SAFETY PRECAUTIONS

Work on refrigerant system should only be performed in a ventilated rooms (workshops). Ensure that with in 5 meters circumference are no working-pits, basement staircases or shafts. Extraction systems are to be switched on.

Reason

The refrigerant emerging is not only colorless and odorless, but also heavier than air and thus displaces oxygen. If refrigerant gas does escape even though all the safety precautions have been followed, there is a risk of suffocating in poorly ventilated areas and in workshop pits - even if it is not noticeable.

Note. The escaping refrigerant/air mixture should not be inhaled, but should be sucked out via an existing exhaust ventilation system.

Do not attempt repair on filled air conditioning systems by soldering, brazing or welding. This pertains also for welding and soldering work on the vehicle, in the event that parts of the climate control system may heat up

Reason

Exposure to heat creates considerable pressure in the system, which could cause it to burst.

Corrective action

Discharge refrigerant circuit, refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Note. Damaged or leaking parts of the air conditioner are never to be repaired by welding or soldering them; they are always to be replaced.

When servicing air conditioner, all open components and pipe connections are to be immediately re-sealed.

Reason

Moisture will ingress into air conditioner components if they are left open for a lengthy period. If this is the case, air conditioners cannot be refilled without having to replace parts of the system.

START/STOP SYSTEM SAFETY PRECAUTIONS

PAINTING VEHICLES WITH A/C

When performing paint work repairs, object temperatures of 80 °C are not to be exceeded in drying booths or their pre-heating areas.

Reason

Exposure to heat creates considerable pressure in the system, which could cause it to burst.

Further information

1. Current A/C system wiring diagrams can be found here, refer to the appropriate SYSTEM WIRING DIAGRAMS information.
2. A data plate in engine compartment indicates the refrigerant used and capacity.
3. Additional information for repairs on vehicles with an A/C system and for handling refrigerant can be found in «REFRIGERANT SAFETY PRECAUTIONS»(ref-496031-S10811128002012082100000) .

CLIMATRONIC CONTROL MODULE

A/C control head, part number 8P0 820 043 with index or up to index C

1. Installed in vehicles equipped with a Sunlight Photo Sensor (3241) -G107- with part number 4E0 907 539

From November 2003, the production was changed over to sunlight photo sensor, part number 8P0 907 539.

Note. From November 2003, a modified sunlight photo sensor and a modified Climatronic control module display was installed. Only sunlight photo sensor with part number 4E0 907 539 must have been/must be installed for Climatronic control module with part number without or up to index C. Sunlight photo sensor with part number 8P0 907 539 or part number 4E0 907 539 may be installed on a Climatronic control module with part number starting with index D, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the assignment between the sunlight photo sensor (3241) and the Climatronic control module is incorrect, the Climatronic control module will not be able to evaluate the signal from the sunlight photo sensor (3241) and the A/C system control will be incorrect, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

A/C control head, part number 8P0 820 043 starting with index D up to index L

1. Installed in vehicles equipped with a sunlight photo sensor (3241) with part number 8P0 907 539

From November 2003, the production was changed over to sunlight photo sensor (3241), part number 8P0 907 539.

Note. Pay attention to the correct allocation for the sunlight photo sensor (3241) (see previous note). This A/C control head may be installed in vehicles with a sunlight photo sensor (3241), part number 4E0 907 539 (note adaptation)

1. Installed on vehicles equipped with a Fresh Air Intake Duct Temperature Sensor -G89

From MY 2006 the Fresh Air Intake Duct Temperature Sensor is discontinued.

Note. From MY 2006, the fresh air intake duct temperature sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic Control Module with part no. as of index M is or may be installed. On vehicles without a fresh air intake duct temperature sensor a Climatronic control module with part number up to index L is installed, an entry in the DTC memory occurs, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Control Module, part number 8P0 820 043 starting with index M up to index AD

1. Installed in vehicles without and with fresh air intake duct temperature sensor.

From MY 2006 the fresh air intake duct temperature sensor is discontinued.

Note. These A/C control heads may also be installed in vehicles with a fresh air intake duct temperature sensor.

1. Installed in vehicles equipped with a Air Flow Door Motor -V71

As of the end of model year 2007, the air flow door motor has been discontinued as a running change.

Note. To the end of model year 2007, the air flow door motor is being discontinued as a running change, on vehicles without the air flow door motor the air flow door (fresh air door) is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to RECIRCULATION DOOR MOTOR . Therefore note the correct allocation of the Climatronic control module, if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". On vehicles without an air flow door motor, a Climatronic control module with part number up to index AD installed, a fault is entered into the DTC memory.

1. Installed on vehicles with a air distribution housing, A/C system with a door in the air vent to the instrument panel defrost vent with side cut-out.

From November 2007, a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed, refer to AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR .

Note. Pay attention to the correct allocation, a A/C control head with part number 8P0 820 043 up to index AD may not be installed in a vehicle equipped with an A/C system air distribution housing with a door in the air outlet to the defrost vent in the instrument panel without side cut-out. If a A/C control head with part number 8P0 820 043 up to index AD is installed in a vehicle with an A/C system air distribution housing with a door in the air outlet to the defrost vents in the instrument panel without a side cut-out, then the window could fog up in the winter because of insufficient air quantity.

Other installation requirements

1. Installed in vehicles equipped with a sunlight photo sensor (3241) with part number 8P0 907 539.

Note. From November 2003, the production was changed over to sunlight photo sensor (3241), part number 8P0 907 539 (see previous note). This A/C control head may be installed in vehicles with a sunlight photo sensor, part number 4E0 907 539, note the adaptation.

A/C control head, part number 8P0 820 043 starting with index AE up to index AH

The production was changed over starting in June 2007 to the A/C control head with part number 8P0 820 043 starting with index AE.

1. Installed in vehicles with and without air flow door motor (note adaptation).

Note. To the end of model year 2007, the air flow door motor is being discontinued as a running change, on vehicles without the air flow door motor the air flow door (fresh air door) is actuated via a curved washer and lever of the recirculation door motor, refer to RECIRCULATION DOOR MOTOR . Therefore note the correct allocation of the Climatronic control module, if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" . A Climatronic control module with part number as of index AE may have been or may be installed in vehicles with and without air flow door motor. So that no DTC for air flow door motor is entered in DTC memory, the adaptation of the Climatronic control module must be corrected, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" . If on vehicles without or with a air flow door motor the Climatronic control module adaptation is performed incorrectly, then there will be an entry in the DTC memory. These Climatronic control modules may also be installed in vehicles with a fresh air intake duct temperature sensor. With this version of the Climatronic control module, there is an ECON button; the ECON button illuminate with the A/C system is switched off. On vehicles equipped with a 2.0L TFSI engine (engine code CAWB), only a Climatronic control module with software version 0430 (on Audi A3 and Audi A3 Sportback) is or will be installed. If vehicle with this engine have a Climatronic control module with software version 0420, then the control of the compressor is shut off by the Climatronic control module due to an unfounded request from the engine control module (the control current is limited to 300 mA, until the pressure in the refrigerant circuit exceeds approximately 7.5 bar) and the A/C cooling performance is unacceptable to the customer.

1. Installed on vehicles with a air distribution housing, A/C system with a door in the air vent to the instrument panel defrost vent with side cut-out (not the adaptation).

From November 2007, a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed, refer to AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR .

Note. From November 2007, a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed. Adapt the Climatronic control module depending on the version of the door (with or with the cut-out on the side) using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" . If the adaptation on vehicles with an A/C air distribution housing with a door in the air outlet to the defrost vents in the instrument panel without a side cut-out is performed incorrectly, then the windshield could fog up in the winter due to insufficient air.

Other installation requirements

1. Installed in vehicles equipped with a sunlight photo sensor (3241) -G107- with part number 8P0 907 539.
2. Installed in vehicle without and with fresh air intake duct temperature sensor -G89- (see previous note).

Note. From November 2003, the production was changed over to sunlight photo sensor (3241), part number 8P0 907 539 (see previous note). This A/C control head may be installed in vehicles with a sunlight photo sensor (3241), part number 4E0 907 539 (note adaptation) From MY 2006 the fresh air intake duct temperature sensor -G89- is discontinued.

A/C Control Head, Part Number 8P0 820 043 Starting With Index BC Through Index BF

Installed on the A3 Cabrio (and on the remaining vehicles with gradual introduction from MY 2009).

Note. Introduction in the other vehicles of the model platform together with the updated interior equipment (planned from MY 2009). On this version of the A/C control head there is, for example, an AC button (instead of an ECON button with Climatronic control module, part number 8P0 820 043 up to index AH), the AC button illuminates with the A/C is on. In addition, the symbols on the button as well as the trim surface are different. On vehicles equipped with a 2.0L TFSI engine (engine code CAWB), only a Climatronic control module beginning with software version 0800 may be installed. If vehicle with this engine have a Climatronic control module with software version 0700, then the control of the compressor is shut off by the Climatronic control module due to an unfounded request from the engine control module (the control current is limited to 300 mA, until the pressure in the refrigerant circuit exceeds approximately 7.5 bar) and the A/C cooling performance is unacceptable to the customer. Refer to CLIMATRONIC CONTROL MODULE .

1. Installed on vehicles with a air distribution housing, A/C system with a door in the air vent to the instrument panel defrost vent without side cut-out (note the adaptation, see above).
2. Installed in vehicles without an Airflow Door Motor -V71

Note. These A/C control heads may (if it is possible due to the version of the center console) be installed in vehicles without air flow door motor -V71- and with an A/C air distribution housing with a door in the air outlet to the defrost vents in the instrument panel with side cut-out (note adaptation, see above).

Other installation requirements

1. Installed in vehicles equipped with a sunlight photo sensor (3241) -G107- with part number 8P0 907 539.
2. Installed in vehicle without and with Fresh Air Intake Duct Temperature Sensor -G89- (see previous note).

Note. From November 2003, the production was changed over to Sunlight Photo Sensor (3241), part number 8P0 907 539 (see previous note). From MY 2006 the Fresh Air Intake Duct Temperature Sensor -G89- is discontinued.

Control Module, part number 8P0 820 043 starting with index BG through index BI

Installed in all vehicles from MY 2009 as a running change.

The specified temperature for the seat heating is controlled to the lower characteristic line (for example, the temperature for 3 is set to 23 °C instead of the former 32 °C and for setting 6 to 38 °C instead of the former 64 °C). Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

The remaining components are the same as those with part number 8P0 820 043 starting with index BC through index BF.

Control Module, with part number 8P0 820 043 and index BK or BL

Installed in vehicle starting with MY 2010 as a running change (installed approximately January 2010).

Contains the additional necessary functions for the Start/Stop System (the signals for the Start/Stop function are being developed, additional measured values and adaptation channels), check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

The remaining components are the same as those with part number 8P0 820 043 starting with index BG through index BI.

Control Module, with part number AP0 820 043 starting with index BM

Installed beginning January 2010 as a running change (necessary on all vehicles with a 1.2L engine)

With the new required functions for a vehicle with a 1.2L engine (for example, the Coolant Pump -V50- motor control via the data bus, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Note. The control of the coolant pump via the Data bus is dependent upon the control of the Climatronic control module, check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Additional information regarding the operating condition of the A/C system via the Databus (evaluated by the Instrument Cluster Control Module -J285- beginning with MY 2011,) check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

The remaining components are the same as those with part number 8P0 820 043 with index BK and BL.

CONTACT CORROSION

Contact corrosion can occur if inappropriate fasteners (bolts, nuts, washers, rivets, plugs, grommets, adhesives etc.) are used.

For this reason, only connecting elements with a special surface coating, e.g. recognized by green color, are installed by manufacturer as well as non-conductive rubber, plastic parts and adhesives.

These parts, which have been tested and are aluminum compatible, are available as replacement parts.

Use only Original Parts.

Always install new parts if there is any doubt as to whether parts can be reused.

Accessory must be approved by Audi AG.

Damage due to contact corrosion is not covered by warranty.

A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT

Note. Only start engine after refrigerant circuit has been assembled. If possible start engine only with a filled refrigerant circuit. Do not start the engine while evacuating the refrigerant circuit or when the circuit is already evacuated (the A/C compressor could be damaged), refer to General Information . The A/C compressor is always driven by the pulley or by the driveshaft (there is no magnetic clutch). To prevent damage when the A/C compressor is idling, it is lubricated by an internal oil circuit. The compressor has an internal oil circuit to ensure the A/C compressor is not damaged when refrigerant circuit is empty. Prerequisite for the internal lubrication is residual refrigerant oil in A/C compressor. The engine may only be started when the refrigerant circuit is installed correctly. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine. As there is no refrigerant in the circuit the oil required to lubricate is not fed to the A/C compressor.

1. All removed parts are re-installed.
2. The refrigerant circuit is filled, refer to «CHARGING REFRIGERANT»(ref-496029-S31209152632012082100000) .

If it is necessary to start the engine with a discharged refrigerant circuit

1. Refrigerant circuit must be fully assembled.
2. There must be no vacuum in the refrigerant circuit.
3. At least 1/4 of the prescribed refrigerant oil must be in the A/C compressor.
4. Do not rev engine higher than 2500 rpm.
5. The engine should only run as long as is absolutely necessary.

Note the following when starting engine for first time after filling refrigerant circuit

Start engine with the A/C compressor switched off (Econ operating mode set, indicator light in AC button does not light up) and wait until engine idle speed has stabilized.

Open all instrument panel vents.

Set the temperature preset on the A/C Control Head Climatronic Control Module -J255- to cold (for the driver and passenger side).

Press the AC button to switch on the A/C compressor (Auto selected and the indicator light in the AC button is on) and let the engine and A/C compressor idle for at least 5 minutes.

Note. Note the information regarding operating the A/C system after filling, refer to General Information .

A/C EVAPORATOR CLEANING

Note. Many different methods for cleaning the evaporator are available on the market. At this time, Audi has tested and approved cleaning the evaporator using the Ultrasound A/C Cleaner VAS 6189A. Odors from the air conditioning system can be caused by various things, only a portion of these orders come from the evaporator and can be corrected by cleaning it with the Ultrasound A/C Cleaner VAS 6189A.

CAUSES OF ODOR

1. Smell like burnt oil.

Mostly forms in the engine compartment due to leaks on the engine or transmission.

1. Sulphurous smell like exhaust.

Due to leaks in the exhaust system.

Through exhaust fumes, which get into the passenger compartment, for example, when driving in reverse through an exhaust gas cloud.

1. Fishy smell like coolant.

From leak at cooling system of engine or of A/C system heater core.

Note. If fishy odor occurs depending on temperature setting (weaker at "Lo" temperature preselect / at "cold" setting than at "Hi" temperature preselect / at "warm" setting), check heating and A/C unit evaporator for leaks (heater core does not have continuous air flow).

1. Smell like a burned clutch.
2. Evaporation from floor mats, decorative seat covers, etc.
3. Rotten, mildewy, moldy or musty smell from plenum chamber.

Due to various contaminants, such as leaves, pine needles, etc. collecting.

Due to water that cannot drain out of the plenum chamber.

Note. Check plenum chamber water drains, refer to CHECKING AND CLEANING PLENUM CHAMBER WATER DRAIN .

1. Smell from air conditioner.

Note. Odors originating in the heating and A/C unit can mainly be detected in fresh air mode and recirculated air mode. If a smell occurs only in fresh air or recirculation mode, the cause is probably not the A/C unit. If heater core is leaking, the odor of escaping coolant depends mainly on the temperature setting, air does not flow continuously through heater core at a Lo temperature setting / at cold setting and the odor is not perceived as strongly.

Due to too much condensation water in A/C unit.

Note. Check condensation drain, refer to CONDENSATE DRAIN HOSE .

Due to an old or heavily contaminated dust and pollen filter.

Note. Check dust and pollen filter, refer to DUST AND POLLEN FILTER .

Due to deposits on evaporator fins.

Note. Clean evaporator with Ultrasonic HVAC Cleaning System VAS 6189, refer to A/C EVAPORATOR, CLEANING WITH ULTRASOUND A/C CLEANER VAS 6189A .

A/C EVAPORATOR, CLEANING WITH ULTRASOUND A/C CLEANER VAS 6189A

Special tools and workshop equipment required

1. Ultrasound A/C Cleaner VAS 6189A
2. Cleaning Fluid VAS 6189/1

Note. Numerous procedures varying in their application and effect are available on the market for cleaning the evaporator. Currently Audi offers the -VAS 6189- which has been approved and released for cleaning the evaporator.

Preparation

Check whether odor is actually in A/C evaporator by switching from fresh air to recirculation.

Note. The odor can only be removed by cleaning with the VAS 6189A if it originates in the evaporator.

Check plenum chamber and water drain valves installed there and clean them if necessary, refer to CHECKING AND CLEANING PLENUM CHAMBER WATER DRAIN .

Remove dust and pollen filter and check it for odor and contamination, refer to DUST AND POLLEN FILTER .

Note. On this vehicle, the dust and pollen filter is installed between Fresh Air Blower -V2- and evaporator, therefore it must be removed for the cleaning.

Clean the installation compartment for dust and pollen filter of heating and A/C unit of leaves, dust and other contaminants, refer to DUST AND POLLEN FILTER .

Reseal opening on A/C unit through which dust and pollen filter was removed.

Start the engine.

Open an instrument cluster vent.

Close the windows and the sunroof.

Settings on vehicles with automatically regulated A/C system (Climatronic Control Module -J255-)

Set operating mode recirculated air mode on A/C system control head and switch off compressor Econ.

Note. Depending on the control head version, Econ is on when the ECON button lights up and the AC is off.

Set the lowest possible temperature for the driver and front passenger side (for example, temperature preselect Lo).

Set the lowest fresh air blower speed and select the air flow direction to instrument panel vents.

Settings on vehicles with manually regulated A/C system (A/C Control Module -J301-)

Set the lowest possible temperature (temperature rotary switch at cold stop) and recirculating air mode.

Switch off the A/C compressor via the AC -button (indicator lamp in AC -button does not light up)

Set the air flow direction to instrument panel vents via the air distribution rotary switch.

Set speed 1 on fresh air blower rotary switch.

Cleaning

Shake bottle of VAS 6189/1 and fill VAS 6189A with it, following operating instructions that come with cleaning system.

Place VAS 6189A in passenger side footwell.

Start VAS 6189A (according to operating instructions) and route outlet hose belonging to it so vapor escaping via A/C unit recirculated air opening (in passenger footwell behind glove compartment) is drawn in by fresh air blower.

Close vehicle doors.

Note. Cleaning procedure lasts approximately 15 to 20 minutes, it is complete when vapor no longer escapes from outlet hose of VAS 6189A.

Finishing Steps

Switch VAS 6189A off.

Switch off ignition.

Open vehicle doors and air out vehicle at least 10 minutes.

Remove VAS 6189A from vehicle and clean it according to operating instructions.

Install dust and pollen filter, refer to DUST AND POLLEN FILTER .

ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS

Connect one wire with a cross section greater than 0.25 mm 2 (e.g. repair wires 000 979 009) each to terminals 5 and 6 of one connector -A- (part number 6Q0 972 706).

Scheme 9

Connect the other end of each wire to a commercially available banana connector -B-.

GENERAL REPAIR INFORMATION

Note. Disconnect Battery before starting electric welding work on vehicle. Refer to [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation .

Refrigerant circuit of A/C system must not be discharged and opened, refer to REFRIGERANT CIRCUIT, DRAINING unless this is necessary because of safety precautions ( REFRIGERANT CIRCUIT REPAIR SAFETY PRECAUTIONS ) or unless components of the refrigerant circuit of the A/C system have to be to replaced.

When performing all other usual vehicle repair work, the refrigerant circuit of the A/C system should remain closed.

Servicing operations that can be performed on the heating and air conditioning system without opening the refrigerant circuit are described in A/C SYSTEM CONTROL AND REGULATION COMPONENTS OUTSIDE PASSENGER COMPARTMENT .

Note. The connections for the senders/switches described are fitted with a valve which closes automatically when the switches are unscrewed. These switches can thus be replaced in any Audi workshop even though the refrigerant circuit is fully charged.

Service work on the A/C system that require the refrigerant circuit to be discharged and thus cannot be performed in every Audi workshop are described in REFRIGERANT CIRCUIT, SERVICING . Certain tools are required to discharge the refrigerant circuit, these work procedures must only be performed by trained personnel as well. Therefore, bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel if necessary, refer to SPECIAL TOOLS .

1. Contact corrosion. Refer to «CONTACT CORROSION»(ref-496031-S42853593862012082100000) .
2. Parking heater information if heat output is poor, refer to «PARKING HEATER, POOR OUTPUT»(ref-496031-S05255155512012082100000) .

REFRIGERANT CIRCUIT O-RINGS

1. Always use O-rings only once, replace.
2. Coat O-ring seals with refrigerant oil before inserting.
3. Make sure O-rings are seated properly on pipe or in groove.
4. Perform the work under clean conditions (even the smallest deposit such as a hair may cause a leak).

Note. Install only O-rings that are resistant to refrigerant R134a and corresponding refrigerant oil. The O-rings are color-coded to avoid mistakes (currently red, light purple and dark purple). The O-ring dimensions -a- and -b- are different depending on installation location. In addition to the color-coded O-ring seals, use is also made at the factory of black O-ring seals for certain connections.

REFRIGERANT CIRCUIT, SERVICING

Note. No refrigerant must be added into the refrigerant circuit (discharge, evacuate and recharge refrigerant circuit). Refer to A/C SERVICE STATION . Compressor is always driven when engine is running; there is no magnetic clutch. Engine is therefore not to be started unless refrigerant circuit has been properly assembled. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. Such internal heat generation results from the fact that - even with delivery near 0 % - the compressor is confronted with a fixed resistance (sealed circuit). To stop the A/C compressor being destroyed when the refrigerant circuit is empty, it is designed such that delivery is reduced to roughly 0 % and lubrication is maintained by way of an internal oil circuit with the oil left in the A/C compressor. The replacement A/C compressor contains all the refrigerant already in the refrigerant circuit, refer to Removal and Installation . The A/C compressors made by Delphi, Zexel / Valeo, Sanden and Denso all have different refrigerant, refer to CAPACITIES, AUDI A3 (8L_) 1997 THROUGH MY 2004 AND AUDI TT (8N_), FROM MY 1999 and refer to REFRIGERANT OILS . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . The specified diameters for O-rings seals and the tightening torques pertain also to the threaded connections of the refrigerant lines or hoses between the separate components. Install O-rings that have been approved specifically for refrigerant R134a. Refer to O-RING SEALS . Check cooling performance, refer to DIAGNOSIS AND TESTING . Check the pressures inside the refrigerant circuit, refer to PRESSURES, CHECKING . For all other refrigerant circuit servicing and testing work not described in this Workshop information, refer to Diagnosis and Testing .

HD = High-pressure end

ND = Low-pressure end

Scheme 10

1. A/C Compressor Regulator Valve -N280- Do not remove. Check activation and function, refer to «A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL»(ref-496031-S22107883002012082100000) . NOTE: The A/C compressor regulator valve is controlled by the Climatronic Control Module -J255- / A/C Control Module -J301-.These control modules control the pressure on the low pressure side of the refrigerant circuit.
2. A/C Compressor A/C compressor, removing from bracket and reinstalling, refer to «COMPRESSOR, REMOVING FROM BRACKET»(ref-496031-S01673880982012082100000) . A/C compressor refrigerant line, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR»(ref-496031-S02917555142012082100000) . To protect the A/C compressor, the engine should only be started with the refrigerant circuit completely assembled. Remove ribbed belt, refer to «RIBBED BELT»(ref-496100-S16261009972012082100000) . A/C compressor, removing and installing, refer to «A/C COMPRESSOR»(ref-496031-S37661620822012082100000) . Depending on time period of production and on engine, compressor construction type may vary. At the beginning of production, A/C compressor was manufactured by Denso (type 7 SEU 16 or 7 SEU 17) were installed; from MY 2004 A/C compressors by other manufacturers (Delphi, Sanden or Zexel) may also be installed. Refer to «Removal and Installation»(ref-496030-S13843556892012082100000) . NOTE: Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on A/C compressor «REFRIGERANT R134A CAPACITIES»(ref-496030-S25528603452012082100000) . Depending on A/C compressor type, different refrigerant oil fill capacities are designated for the refrigerant circuit. The reason for the different oil capacities in the A/C compressor for an otherwise identical refrigerant circuit lies in the design of the A/C compressor itself, note these oil capacities. Too much oil in the circuit leads to higher pressures and reduces cooling performance of the system. Too little oil may lead to lubrication problems in the compressor. If a new compressor has been installed or new refrigerant oil has been put into the A/C compressor (e.g. after blowing through the A/C system), the A/C compressor must be turned by hand approximately 10 revolutions. This ensures that the compressor is not damaged when activated.
3. Belt Pulley Replacing, refer to «A/C COMPRESSOR AND PULLEY»(ref-496031-S28022874062012082100000) . Ribbed belt, removing and installing, refer to «RIBBED BELT»(ref-496100-S16261009972012082100000) . The Delphi A/C compressor belt pulley cannot be removed separately. NOTE: There is an overload protection installed between the belt pulley and the A/C compressor input shaft to protect the belt should the A/C compressor get blocked or be difficult to move. If the A/C compressor is runs with resistance, the overload safeguard interrupts the supply of power to it. Rubber elements are installed between belt pulley and A/C compressor driveshaft, vibrations which may occur during A/ C compressor operation may be dissipated via these rubber elements (damper function at torque fluctuations). Different versions of the pulley are installed depending on the type of A/C compressor and engine, refer to «A/C COMPRESSOR AND PULLEY»(ref-496031-S28022874062012082100000)
4. Oil Drain Plug Denso and Delphi A/C compressors have a sealing ring installed, replace. Sanden A/C compressors have an O-ring (8.8 mm x 1.5 mm) installed, always replace. Zexel/Valeo A/C compressors have an O-ring (7.6 mm x 1.9 mm) installed, always replace. NOTE: Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. Tightening specifications: Denso A/C compressor 30 Nm, Sanden- A/C compressor and Zexel- A/C compressor 10 Nm. Tightening specifications: Delphi A/C compressor 15 Nm. Should only be unscrewed to drain refrigerant oil and with the A/C compressor removed. Turn the A/C compressor via belt pulley, to speed up refrigerant oil drainage. Refer to «Removal and Installation»(ref-496030-S13843556892012082100000) .
5. Pressure Relief Valve Do not remove Tightening specification: Sanden A/C compressor 14.5 Nm, Denso A/C compressor and Zexel / Valeo A/C compressors 10 Nm with O-ring Denso A/C compressor, Sanden A/C compressor and Zexel / Valeo A/C compressor: 8.5 mm x 1.75 mm Delphi A/C compressor with sealing ring, tightening specification: 15 Nm.
6. Connection With Valve Different component locations depending on engine, item 6a shows component location in vehicles with 2.0 L Diesel engine. For removing and installing the valve set when the refrigerant circuit is evacuated, for example, use an adapter from the Socket For A/C Valves T10364.
7. High Pressure Sensor -G65- Removing and installing, refer to «HIGH PRESSURE SENSOR»(ref-496031-S27653584002012082100000) . Checking signal, refer to «HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL»(ref-496031-S06625037082012082100000) . Different component locations depending on engine, item 7a shows component location in vehicles with 2.0 L Diesel engine.
8. Condenser Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM CONDENSER»(ref-496031-S25394329412012082100000) . Condenser, removing and installing, refer to «CONDENSER»(ref-496031-S03462588382012082100000) .
9. Fluid Reservoir Coat O-ring seals lightly with refrigerant oil before installing, refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) . Replace the O-ring seals. Removing and installing, refer to «FLUID RESERVOIR»(ref-496031-S18973378922012082100000) . Different versions (secured by one or two bolts, with or without seals against moisture in connection area). NOTE: The reservoir may be attached to or integrated in the condenser, depending on the version of the condenser. Refer to «FLUID RESERVOIR»(ref-496031-S18973378922012082100000) and «DRYER CARTRIDGE»(ref-496031-S09859365112012082100000) . Dryer cartridge (on a condenser with an integrated fluid reservoir), removing and installing, refer to «DRYER CARTRIDGE»(ref-496031-S09859365112012082100000) .
10. Service Connection High pressure side. Different versions (with primary sealing valve or with Schrader valve) depending on refrigerant line, distinguishing characteristics, refer to «CONNECTIONS FOR QUICK-RELEASE COUPLING ON REFRIGERANT CIRCUIT»(ref-496029-S25621235942012082100000) . For the A/C Service Station for measuring, discharging and recharging using service station, refer to «A/C SERVICE STATION»(ref-496029-S11545816402012082100000) . Depending on engine version, it may be necessary to remove some components (e.g. EVAP canister) in order to be able to connect to service coupling. For removing and installing the service connection or the valve set when the refrigerant circuit is evacuated, for example, use an adapter from the Socket For A/C Valves T10364. WARNING: Only remove service connections when the refrigerant circuit is empty. The connection does not have a valve.
11. Sealing Cap With a seal. Always screw on.
12. Expansion Valve Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE»(ref-496031-S08812543432012082100000) . Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) . NOTE: After switching off the A/C compressor on this vehicle, it may take a long time until the pressure on the high pressure side (the expansion valve is cold and the pressure on the low pressure side increases quickly after switching off, the expansion valve closes and the refrigerant can flow slowly on the low pressure side.
13. Evaporator A/C unit with evaporator, removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . Removing and installing evaporator from heating A/C unit, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) .
14. Service Connection Low pressure side. Different versions (with primary sealing valve or with Schrader valve) depending on refrigerant line, distinguishing characteristics, refer to «CONNECTIONS FOR QUICK-RELEASE COUPLING ON REFRIGERANT CIRCUIT»(ref-496029-S25621235942012082100000) . For the A/C Service Station for measuring and discharging using service station, refer to «A/C SERVICE STATION»(ref-496029-S11545816402012082100000) . Depending on engine version, it may be necessary to remove some components (e.g. EVAP canister) in order to be able to connect to service coupling. For removing and installing the service connection or the valve set when the refrigerant circuit is evacuated, for example, use an adapter from the Socket For A/C Valves T10364. WARNING: Only remove service connections when the refrigerant circuit is empty. The connection does not have a valve.
15. Sealing Cap With a seal. Always screw on.
16. Pre-Volume Is a component of refrigerant line from expansion valve to A/C compressor. Pressure fluctuations are damped in the pre-volume. Not installed in all vehicles (currently only on 2.0L diesel engines).
17. Connection in Refrigerant Line Replace the O-ring seal. Not installed in all vehicles (for example, installed in 6-cylinder vehicles). Disconnecting and connecting connection, refer to «CONNECTING POINTS IN REFRIGERANT LINE, DISCONNECTING AND CONNECTING»(ref-496031-S09429574542012082100000) .

RECIRCULATION DOOR MOTOR

Vehicles With Automatically Regulated A/C System

Note. Different versions of Recirculation Door Motor V113 in vehicles with manually and automatically regulated A/C system. On vehicles withe manual climate control system, a motor with an end switch and without a potentiometer is installed. Removing and installing, refer to recirculation door motor on a vehicle with a manual climate control system, refer to FRESH/RECIRCULATION AIR DOOR MOTOR . Different versions of recirculation door motor in vehicles with an automatic climate control system with and without Air Flow Door Motor -V71- . To the end of model year 2007, the air flow door motor is being discontinued as a running change, on vehicles without the air flow door motor the air flow door (fresh air door) is actuated via a curved washer and lever of the recirculation door motor. Check the motor: Connect both terminals 5 and 6 in control motor connector to 12 V (DC), the motor moves in one direction until stop, the direction of rotation changes by interchanging B+ and Ground. Use an adapter cable. Refer to ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS . Perform Basic Setting of A/C system after installing a new control motor using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Using Guided Fault Finding it is possible to check the control for the A/C electrical components, for example to check for interchanging during the basic setting. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

1. Removing and installing air recirculation door motor on vehicles with a air flow door motor, refer to «RECIRCULATION DOOR MOTOR WITH AIR FLOW DOOR MOTOR»(ref-496031-S20597107642012082100000) .
2. Removing and installing air recirculation door motor on vehicles without a air flow door motor, refer to «RECIRCULATION DOOR MOTOR WITHOUT AIR FLOW DOOR MOTOR»(ref-496031-S08163770972012082100000) .

A/C COMPRESSOR BELT PULLEY, DENSO VERSION 1

Note. This type of belt pulley is installed on a 7 SEU 16 A/C compressor. Different versions of the belt pulley are installed, depending on A/C compressor construction type and engine version. Belt Pulley, removing and Installing, refer to BELT PULLEY, DENSO VERSION 1 .

Scheme 11

1. Screw Replace. Tightening specification 20 Nm. Loosening and tightening, refer to «BELT PULLEY, DENSO VERSION 1»(ref-496031-S22981530322012082100000) .
2. Drive Plate Different versions. Removing and installing, refer to «BELT PULLEY, DENSO VERSION 1»(ref-496031-S22981530322012082100000) . The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor.
3. Circlip Replace. Install on correct side (flat side toward A/C compressor). Removing and installing, refer to «BELT PULLEY, DENSO VERSION 1»(ref-496031-S22981530322012082100000) .
4. Belt Pulley The overload protection takes over when the rubber element on the belt pulley loosens because the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. Different versions. Removing and installing, refer to «BELT PULLEY, DENSO VERSION 1»(ref-496031-S22981530322012082100000) . NOTE: Under certain conditions (e.g. rough engine idle), rubber element of pulley can disengage without a malfunction existing at compressor or in refrigerant circuit.
5. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley.

A/C COMPRESSOR BELT PULLEY, DENSO VERSION 2

Note. This type of belt pulley is installed on a 7 SEU 17 A/C compressor. Different versions of the pulley may be installed, depending on A/C compressor construction type and engine version. Belt Pulley, removing and Installing, refer to BELT PULLEY, DENSO VERSION 2 .

Scheme 12

1. Circlip Remove carefully using a small screwdriver or needle-nose pliers (especially note belt pulley when doing this). As of model year 2006, circlips with a rubber disc vulcanized on to them are installed as a running change, this rubber disc replaces the plastic disc which could be glued on up to then (not present on all compressors), refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) . Removing and installing, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) .
2. Drive Plate Attached to the A/C compressor input shaft. Different versions. The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. Removing and installing, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) . Tightening specification 35 Nm. A plastic washer may be glued on, depending on time period of production, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) .
3. Circlip Replace. Install on correct side (flat side toward A/C compressor). Removing and installing, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) .
4. Spacer Dimension: 17.5 x 10 x 3 mm.
5. Rubber Elements 6x, install on proper side, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) . Decouples belt pulley from A/C compressor input shaft, damps vibrations and noise. For installation, lightly coat rubber elements, e.g. with tire mounting paste or a soap solution (as a lubricant).
6. Belt Pulley Belt pulley is made of plastic and is sensitive to impact, therefore handle it with especial care. Different versions. Removing and installing, refer to «BELT PULLEY, DENSO VERSION 2»(ref-496031-S16394434602012082100000) .
7. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley.

A/C COMPRESSOR BELT PULLEY, DENSO VERSION 3

Note. This type of belt pulley is installed on a 6 SEU 14 A/C compressor. Different versions of the belt pulley are installed, depending on A/C compressor construction type and engine version. If overload protection of pulley triggers, check the A/C compressor for ease of motion before replacing the pulley. If the A/C compressor creates friction, replace it completely. Observe notes for removing belt pulley of version 1, these also apply for version 3. Refer to BELT PULLEY, DENSO VERSION 1 . To remove belt pulley, it depends on engine version if it is necessary to remove A/C compressor from engine. Refer to COMPRESSOR, REMOVING FROM BRACKET . As a replacement part, the pulley with the drive plate wand the cap come under one part number. The pulley and the drive plate are held together with one bolt (when the bolt is no longer needed, dispose of it). When the bolt was manufactured, a predetermined amount of a specific grease was applied to the threads in the drive plate; this amount is sufficient for bolting the drive plate to the compressor one time (a drive plate, which has been removed, cannot be reused). Belt Pulley, Removing and Installing, refer to BELT PULLEY, DENSO VERSION 3

Scheme 13

1. Sealing Cap
2. Drive Plate Replace. Bolted with the A/C compressor driveshaft, clean the compressor shaft thread before mounting the drive plate. NOTE: The thread of the new drive plate has already been greased with a specific amount of a grease by the manufacturer. Different versions. the overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. With rubber elements for de-coupling belt pulley from A/C compressor input, dampens rations and noise. For installation, lightly coat rubber elements, e.g. with tire mounting paste or a soap solution (as a lubricant). Removing and installing, refer to «BELT PULLEY, DENSO VERSION 3»(ref-496031-S09601418552012082100000) . Tightening specification 30 Nm.
3. Circlip Replace. Install on correct side (flat side toward A/C compressor). Removing and installing, refer to «BELT PULLEY, DENSO VERSION 3»(ref-496031-S09601418552012082100000) .
4. Belt Pulley Belt pulley is made of plastic and is sensitive to impact, therefore handle it with especial care. Different versions (depending, for example, on the type of engine). Removing and installing, refer to «BELT PULLEY, DENSO VERSION 3»(ref-496031-S09601418552012082100000) .
5. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley. Clean the compressor shaft thread before installing the drive plate and lightly coat it the lubricant.

A/C COMPRESSOR BELT PULLEY, ZEXEL / VALEO

Note. Observe notes for removing belt pulley for compressor manufactured by Denso version 1, these also apply to this A/C compressor, refer to BELT PULLEY, DENSO VERSION 1 . Perform any preliminary work as described for removing belt pulley on compressor manufactured by Denso version 1. Refer to BELT PULLEY, DENSO VERSION 1 . On A/C compressors with part number 1K0 820 803 as of index N, the drive plate splines are bonded to A/C compressor shaft splines, removing drive plate, refer to A/C COMPRESSOR BELT PULLEY, ZEXEL/VALEO . On A/C compressors with part number 1K0 820 803 up to index L, the drive plate splines are not bonded to A/C compressor shaft splines, removing drive plate. On these A/C compressors it may be possible that the drive plate splines are worn off and the A/C compressor is no longer driven. Refer to A/C COMPRESSOR BELT PULLEY, ZEXEL/VALEO . In this case, check the A/C compressor for freedom of movement and if necessary replace drive plate, use the repair set 1K0 898 814 to do so. Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Scheme 14

1. Screw Replace. To loosen and tighten bolt, hold belt pulley firmly in place using a standard band wrench (with webbing). Clean threads on A/C compressor shaft (and on bolt if necessary) of old thread locking compound before screwing on. Install the bolts with thread locking compound (for example, D 000 600 A2). Tightening specification 17 Nm.
2. Screw To loosen and tighten bolt, hold belt pulley firmly in place using a standard band wrench (with webbing). Clean threads on A/C compressor shaft (and on bolt if necessary) of old thread locking compound before screwing on. Install the bolts with thread locking compound (for example, D 000 600 A2). Tightening specification 7 Nm
3. Drive Plate The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. With rubber element for de-coupling belt pulley from A/C compressor driveshaft (damps vibrations and noise). On A/C compressors with part number 1K0 820 803 as of index N, the drive plate splines are bonded to A/C compressor shaft splines, removing drive plate, refer to «A/C COMPRESSOR BELT PULLEY, ZEXEL/VALEO»(ref-496031-S15349408232012082100000) . On A/C compressors with part number 1K0 820 803 up to index L, the drive plate splines are not bonded to A/C compressor shaft splines, removing drive plate. On these A/C compressors it may be possible that the drive plate splines are worn off and the A/C compressor is no longer driven. NOTE: If drive plate has already been replaced once in customer service and was bonded at that time using sealing compound D 154 102 A1, it may be joined so securely to the compressor shaft that it can no longer be pressed off, refer to «A/C COMPRESSOR BELT PULLEY, ZEXEL/VALEO»(ref-496031-S15349408232012082100000) , in this case the entire compressor must be replaced.
4. Circlip Replace. Install on proper side, beveled insertion edge -A- faces away from A/C compressor (install flat side facing the A/C compressor). When installing circlip, note that it cannot be bent open more than is necessary for installation.
5. Belt Pulley Clean A/C compressor flange before sliding on pulley.
6. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley.

A/C COMPRESSOR BELT PULLEY, SANDEN

Note. Observe notes for removing belt pulley for compressor manufactured by Denso version 1, these also apply to this A/C compressor, refer to BELT PULLEY, DENSO VERSION 1 . Perform any preliminary work as described for removing belt pulley on compressor manufactured by Denso version 1. Refer to BELT PULLEY, DENSO VERSION 1 . The A/C compressor belt pulley is available in different versions, belt pulley version 1 is installed on A/C compressors with part number 1K0 820 803 up to index Q, belt pulley version 2 is installed on A/C compressors with part number 1K0 820 803 as of index S (running change as of December 2005).

Replacing Belt Pulley Version 1

Scheme 15

1. Hex Head Nut To loosen and tighten hex nut, hold belt pulley firmly in place using a standard band wrench (with webbing). Clean threads of hex nut and threads of A/C compressor shaft of old thread locking compound before screwing on. Install the hex nut with thread locking compound (e.g. with D 000 600 A2). Tightening specification 25 Nm.
2. Screw To loosen and tighten bolts, hold belt pulley firmly in place using a standard band wrench (with webbing). Clean old bolt locking compound from thread of bolts and threads of belt pulley before screwing on. Install the bolts with thread locking compound (for example, D 000 600 A2). Tightening specification 4.5 Nm.
3. Drive Plate The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. With rubber element for de-coupling belt pulley from A/C compressor driveshaft (damps vibrations and noise).
4. Washer
5. Circlip Replace. Install on proper side, beveled insertion edge -A- faces away from A/C compressor (install flat side facing the A/C compressor). When installing circlip, note that it cannot be bent open more than is necessary for installation.
6. Belt Pulley Clean A/C compressor flange before sliding on pulley.
7. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley.

Replacing belt pulley version 2

Note. From MY 2008, for cold climate vehicles (for example, central and north Europe), compressors with a smaller stroke installed; on these compressors, the belt pulley is slightly different from the one illustrated here (the rubber elements -B- are, for example, as a vibration damper not present).

Scheme 16

1. Hex head nut NOTE: The A/C compressor shaft may be covered with a plastic cap to protect the threads on it (the plastic cap is not illustrated). To loosen and tighten hex nut, hold belt pulley firmly in place using a standard band wrench (with webbing). Clean threads of hex nut and threads of A/C compressor shaft of old thread locking compound before screwing on. Install the nut/bolt with thread locking compound (for example, D 000 600 A2). Nut tightening specification: 25 Nm.
2. Screw To loosen and tighten bolts, hold belt pulley firmly in place using a standard band wrench (with webbing). Tightening specification 12 Nm. Clean old bolt locking compound from thread of bolts and threads of belt pulley before screwing on. Install the bolts with thread locking compound (for example, D 000 600 A2).
3. Drive Plate The overload protection (securing spring elements), takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor. Drive plate spring elements damp vibrations and noise.
4. Circlip Replace. Install on proper side, beveled insertion edge -A- faces away from A/C compressor (install flat side facing the A/C compressor). When installing circlip, note that it cannot be bent open more than is necessary for installation.
5. Belt Pulley Clean A/C compressor flange before sliding on pulley. With rubber elements -B- and threaded plates -C- for de-coupling belt pulley from A/C compressor input shaft (rubber elements damp vibrations and noise). NOTE: The threaded plates -C- can also be connected to each other by a ring, depending on the version.
6. A/C Compressor Different versions may be installed, depending on engine version and country version of vehicle. Clean A/C compressor flange before sliding on pulley.

A/C SYSTEM CONTROL AND REGULATION COMPONENTS OUTSIDE PASSENGER COMPARTMENT

Note. Vehicles with automatically regulated A/C system, Climatronic Control Module -J255- evaluates the signals from various components and actuates the compressor via the A/C Compressor Regulator Valve -N280-. Vehicles with manual climate control system, the A/C Control Module -J301- evaluates the signals from various components and actuates the A/C compressor via the A/C compressor regulator valve. If there is a malfunction in the system, first check DTC memory of Climatronic control module / A/C control module using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If no fault is displayed, then read the measured value block for the Climatronic control module / the A/C control module and test the component using the "control diagnosis" function of the Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Servicing operations on refrigerant circuit are described in REFRIGERANT CIRCUIT, SERVICING . Perform the following work on completion of repair operations

Check DTC memory of Climatronic control module / of A/C control module and erase any malfunctions displayed.

Check coding of Climatronic control module.

If necessary, check adaptation of Climatronic control module.

Perform basic setting of A/C system (Climatronic control module / A/C control module) using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

COMPONENTS OUTSIDE PASSENGER COMPARTMENT, GROUP 1

Note. The following illustration shows the allocation of the components on the Audi A3; the allocation of the components applies (with a few differences) applies also the Audi A3 Sportback and the Audi A3 Cabrio.

Scheme 17

1. Heated Windshield -Z2- Activation occurs via Heated Windshield Control Module -J505-. Refer to Electrical Equipment. Introduction as optional equipment not yet finalized. Removing and installing front windshield, refer to «Removal and Installation»(ref-496128-S42699883992012082100000) .
2. Sun Roof (With Solar Cells) Introduction as optional equipment not yet finalized. Removing and installing, refer to «Removal and Installation»(ref-496129-S22116969192012082100000) .
3. Heated Rear Window -Z1- The request is sent by the Climatronic Control Module -J255- / by the A/C Control Module -J301- via the CAN-bus Comfort system, activation of the heated rear window occurs via the Vehicle Electrical System Control Module -J519-. Refer to Electrical Equipment and Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Heated rear window function, check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Removing and installing rear window, refer to «Removal and Installation»(ref-496128-S42699883992012082100000) .
4. Forced Air Extractor Fitted on left and right beneath rear bumper. Sealing doors on air extraction vent must be able to move freely and close automatically. In order for the passenger compartment ventilation to function properly, the air ducts that run through the luggage compartment trim must be unobstructed. Checking, refer to «VENT FRAME, CHECKING»(ref-496031-S32401851722012082100000) .
5. Fluid Reservoir May only be removed when refrigerant circuit has been discharged; bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to «FLUID RESERVOIR»(ref-496031-S18973378922012082100000) . Removing and installing, refer to «FLUID RESERVOIR»(ref-496031-S18973378922012082100000) . NOTE: The reservoir may be attached to or integrated in the condenser, depending on the version of the condenser. Refer to «FLUID RESERVOIR»(ref-496031-S18973378922012082100000) and «DRYER CARTRIDGE»(ref-496031-S09859365112012082100000) . Dryer cartridge (on a condenser with an integrated fluid reservoir), removing and installing, refer to «DRYER CARTRIDGE»(ref-496031-S09859365112012082100000) .
6. Condenser May only be removed when refrigerant circuit has been discharged; bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel «CONDENSER»(ref-496031-S03462588382012082100000) . Different versions (depending on vehicle equipment): «A/C COMPRESSOR, MECHANICALLY DRIVEN»(ref-496029-S27205921652012082100000) or refer to «A/C COMPRESSOR, ELECTRICALLY DRIVEN»(ref-496029-S11880167632012082100000) and refer to «CONDENSER»(ref-496029-S34081958792012082100000) . Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM CONDENSER»(ref-496031-S25394329412012082100000) . Condenser, removing and installing, refer to «CONDENSER»(ref-496031-S03462588382012082100000) .
7. Stone Deflector For Condenser Installed only with certain optional equipment.
8. Outside Air Temperature Sensor -G17- Removing -- Remove the bumper cover. Refer to «Removal and Installation»(ref-496059-S33906163212012082100000) . -- Unplug connector at temperature sensor and unclip from mount in air duct The measured value of the outside air temperature sensor is evaluated by the Instrument Cluster Control Module -J285- and transmitted via the CAN-Bus system to the Climatronic control module / A/C control module), refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function.
9. A/C Compressor Regulator Valve -N280- For checking activation and functionality, refer to «A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL»(ref-496031-S22107883002012082100000) .
10. A/C Compressor A/C compressor, removing from bracket and reinstalling, refer to «COMPRESSOR, REMOVING FROM BRACKET»(ref-496031-S01673880982012082100000) . A/C compressor refrigerant line, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR»(ref-496031-S02917555142012082100000) . A/C compressor, removing and installing, refer to «A/C COMPRESSOR»(ref-496031-S37661620822012082100000) . Depending on time period of production and on engine, compressor construction type may vary «REFRIGERANT CIRCUIT COMPONENT OVERVIEW»(ref-496031-S00075445612012082100000) . Ribbed Belt, Removing and Installing, refer to «RIBBED BELT»(ref-496100-S16261009972012082100000) . Replace the belt pulley, refer to «A/C COMPRESSOR»(ref-496031-S37661620822012082100000) .
11. Pre-Volume Is a component of refrigerant line from expansion valve to A/C compressor. Pressure fluctuations are damped in the pre-volume. Not installed in all vehicles (currently not installed on the 2.0L diesel engine).
12. Label With specifications for type of refrigerant and designated fill capacity, refer to «STICKER FOR CAPACITY OF REFRIGERANT R134A»(ref-496030-S01977586322012082100000) and refer to «REFRIGERANT R134A CAPACITIES»(ref-496030-S25528603452012082100000) .
13. Plenum Chamber Water Drains Checking, cleaning, refer to «CHECKING AND CLEANING PLENUM CHAMBER WATER DRAIN»(ref-496031-S23384906892012082100000) .

COMPONENTS OUTSIDE PASSENGER COMPARTMENT, GROUP 2

Note. The following illustration shows the allocation of the components on the Audi A3; the allocation of the components applies (with a few differences) applies also the Audi A3 Sportback and the Audi A3 Cabrio.

Scheme 18

1. Condensation Drain Checking, removing and installing, refer to «CONDENSATE DRAIN HOSE»(ref-496031-S18551473692012082100000) .
2. Expansion Valve Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE»(ref-496031-S08812543432012082100000) . Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) . NOTE: After switching off the A/C compressor on this vehicle, it may take a long time until the pressure on the high pressure side (the expansion valve is cold and the pressure on the low pressure side increases quickly after switching off, the expansion valve closes and the refrigerant can flow slowly on the low pressure side.
3. Coolant Fan -V7- The request to switch on Coolant Fan(s) is transmitted by Climatronic Control Module -J255- or from the A/C Control Module -J301- via the Bus system to the Engine Control Module (ECM). Engine Control Module then actuates the fan(s) directly or via the Coolant Fan Control Module -J293-, check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function (for ECM) and refer to the appropriate SYSTEM WIRING DIAGRAMS information. The respective ECM switches e.g. the coolant fan (via the coolant fan control module) continuously to the desired output (depending on engine type). Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function (for the ECM). Different versions are installed depending on vehicle equipment. Check actuation by Climatronic control module or from the A/C control module using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
4. High Pressure Sensor -G65- Function, removing and installing, refer to «HIGH PRESSURE SENSOR»(ref-496031-S27653584002012082100000) . Measured value of high pressure sensor is displayed in the function "Read measured values block" Climatronic control module / A/C control module, refer to «HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL»(ref-496031-S06625037082012082100000) and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
5. Connection Point In Refrigerant Line Not installed in all vehicles (for example, installed in 6-cylinder vehicles).
6. Service Connection High pressure side. For measuring and discharging the refrigerant circuit, refer to «CONNECTING FOR MEASURING AND TESTING, ONE SERVICE CONNECTION»(ref-496029-S40677885562012082100000) and refer to «EVACUATING REFRIGERANT CIRCUIT»(ref-496029-S41165649782012082100000) and refer to «DRAINING REFRIGERANT CIRCUIT»(ref-496029-S28767610182012082100000) . Cap with seal, always install. Depending on engine version, it may be necessary to remove some components (e.g. EVAP canister) in order to be able to connect to service coupling.
7. Service Connection Low pressure side. For measuring and discharging refrigerant circuit, refer to «CONNECTING FOR MEASURING AND TESTING, ONE SERVICE CONNECTION»(ref-496029-S40677885562012082100000) and refer to «EVACUATING REFRIGERANT CIRCUIT»(ref-496029-S41165649782012082100000) and refer to «DRAINING REFRIGERANT CIRCUIT»(ref-496029-S28767610182012082100000) . Cap with seal, always install. Depending on engine version, it may be necessary to remove some components (e.g. EVAP canister) in order to be able to connect to service coupling.
8. Fresh Air Intake Cover Check for proper seating, prevents water from entering the intake housing of heating A/C unit. Removing and installing, refer to «AIR INTAKE COVER»(ref-496031-S07973528862012082100000) and «Removal and Installation»(ref-496059-S33906163212012082100000) .
9. Air Quality Sensor -G238- Function, refer to «AIR QUALITY SENSOR FUNCTION»(ref-496031-S11723876312012082100000) . Checking, refer to «AIR QUALITY SENSOR, CHECKING»(ref-496031-S19186905972012082100000) . Removing and installing, refer to «AIR QUALITY SENSOR»(ref-496031-S25691218962012082100000) . Not installed in all vehicles (optional equipment at this time).
10. Intake Grille For Fresh Air Intake Check for proper seating, prevents foreign objects (e.g. leaves) entering the A/C intake housing. Check bonded seals for damage and proper seating. This seal prevents water from flowing through beneath the intake grille into heating A/C unit intake housing. Removing and installing, refer to «AIR INTAKE GRILLE»(ref-496031-S21738677832012082100000) .
11. Fresh Air Intake Duct Temperature Sensor -G89- Removing and installing, checking resistance value, refer to «FRESH AIR INTAKE DUCT TEMPERATURE SENSOR»(ref-496031-S34189917812012082100000) . Installed only on vehicles with automatically regulated A/C system up to model year 2006 (discontinued as running change in model year 2006). NOTE: In model year 2006, the fresh air intake duct temperature sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic control module with part number as of index M is or may be installed. On vehicles without fresh air intake duct temperature sensor, an Climatronic control module with part no. up to index L installed enters a DTC into the DTC memory.

A/C SYSTEM CONTROL AND REGULATION COMPONENTS INSIDE PASSENGER COMPARTMENT

Note. Vehicles with automatically regulated A/C system: The Climatronic Control Module -J255- evaluates the signals from various components and actuates the compressor via the A/C Compressor Regulator Valve -N280-. Vehicles with manual climate control system: the A/C Control Module -J301- evaluates the signals from various components and actuates the A/C compressor via the A/C compressor regulator valve. If there is a malfunction in the system, first check DTC memory of Climatronic control module or of the A/C control module using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If no fault is displayed, then read the measured value block for the Climatronic control module / the A/C control module and test the component using the "control diagnosis" function of the Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Servicing operations on refrigerant circuit are described in REFRIGERANT CIRCUIT, SERVICING . Perform the following work on completion of repair operations

Check DTC memory of Climatronic control module / or A/C control module and erase any malfunctions displayed.

Check coding of the Climatronic control module.

If necessary, check adaptation of the Climatronic control module.

Perform A/C system basic setting using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

1. The electrical tests for various motors, potentiometers and sensors is described in Guided Fault Finding of the Vehicle Diagnosis, Testing and Information System VAS 5051.

Scheme 19

1. Diagnostic Connection Perform On Board Diagnostic (OBD) on A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
2. Accelerator Mechanism The request for the kick-down shut-off by the Climatronic Control Module -J255- / by the A/C Control Module -J301- kick-down switch-off, via the A/C Compressor Regulator Valve -N280- is made by the Engine Control Module (ECM). The data is exchanged via the data bus. The actual condition can be read in the Climatronic control module or in the A/C control module measured values block using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" (for the A/C system and the engine control module).
3. Left Footwell Vent Removing and installing vent, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
4. Left Front Seat Temperature Sensor -G344- and Left Front Heated Seat -Z45- Seat heater is not installed in all vehicles (optional equipment). Vehicles with automatically regulated A/C system: activation of seat heater is displayed in measured value block of Climatronic control module, check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Vehicles with manually regulated A/C system: function and activation of seat heater check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Seat heating, servicing, refer to «Removal and Installation»(ref-496130-S14637100472012082100000) . NOTE: From MY 2009, as a running change, the Climatronic control module (or control modules for seat heating) is being installed, whereby the specified temperature is set to a lower characteristic line. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
5. Left Vent Temperature Sensor -G150- Not installed on vehicles with manually regulated A/C system. Removing and installing, refer to «LEFT VENT TEMPERATURE SENSOR»(ref-496031-S25273106832012082100000) .
6. Defroster Vent Side window/driver side. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
7. Instrument Panel Vent, Left Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
8. Instrument Cluster Control Module -J285- With Outside Air Temperature Display -G106-. The measured value from the Outside Air Temperature Sensor -G17- is evaluated by the control module inside the instrument cluster and then transmitted to the Climatronic control module or to the A/C control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. The Climatronic control module calculates the current outside temperature from the outside temperature received and sends it back to the Instrument Cluster Control Module. Ambient temperature sent by Climatronic control module is displayed in the outside air temperature display. If the temperature display if faulty, check the measured values of the temperature sensor (vehicles with automatic A/C) using. Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Vehicles with manually regulated A/C system: the temperature that is calculated by Instrument Cluster Control Module due to the measured value of outside air temperature sensor is displayed in Outside Air Temperature Display.
9. Left Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
10. Right Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
11. Climatronic Control Module -J255- / A/C Control Module -J301- Climatronic Control Module (on vehicles with automatically regulated A/C system) Different versions (with a button for automatic air recirculation or a OFF button, without or with seat heater control, with and without radio navigation system or radio with large control panel), allocation Removing and installing, refer to «CLIMATRONIC CONTROL MODULE»(ref-496031-S06146725432012082100000) . Instrument Panel Interior Temperature Sensor -G56- is integrated in the Climatronic control module. Interior Temperature Sensor Fan -V42- is installed in the Climatronic control module, however it cannot be replaced individually, refer to «INTERIOR TEMPERATURE SENSOR FAN»(ref-496031-S25199706692012082100000) . Also observe additional notes for Climatronic control module, refer to «CLIMATRONIC CONTROL MODULE»(ref-496031-S06146725432012082100000) . Guided fault finding of the Climatronic control module is to be performed as described using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Buttons and display fields are illuminated by Light Emitting Diodes (LED), cannot be replaced. NOTE: Different versions on vehicles with and without Fresh Air Intake Duct Temperature Sensor -G89- From model year 2006, the fresh air intake duct temperature sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic control module with part no. as of index M is or may be installed. On vehicles without fresh air intake duct temperature sensor, a Climatronic control module with part no. up to index L installed enters a DTC into the DTC memory. To the end of model year 2007, the Air Flow Door Motor -V71- is being discontinued as a running change, on vehicles without the air flow door motor the air flow door (fresh air door) is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) . Therefore note the correct allocation of the Climatronic control module, if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction, refer to «CLIMATRONIC CONTROL MODULE»(ref-496031-S06146725432012082100000) . From MY 2009, as a running change, the Climatronic control module is being installed, whereby the specified temperature is set to a lower characteristic line. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with Start/Stop system, the Climatronic control module prevents the Stop function. If, for example, defrost is selected, the Stop Function is not possible or will be interrupted and the engine will start. The same applies in the case of heating and cooling. The difference between the selected and actual temperature is greater than a specified value. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the vehicle has the Start/Stop System, there is no additional coolant pump. An electric coolant pump may be present depending on the vehicle engine, which is controlled by an ECM. Refer to «GENERAL INFORMATION»(ref-496029-S17085270722012082100000) and refer to «COOLANT PUMP AND COOLANT THERMOSTAT ASSEMBLY OVERVIEW»(ref-496039-S06878524212012082100000) and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". On vehicles with the Start/Stop System, only the Climatronic control module, part number 8P0 820 047 starting with index BK is or will be installed. Refer to the «CLIMATRONIC CONTROL MODULE»(ref-496031-S06146725432012082100000) . A/C Control Module -J301- (vehicles with manually regulated A/C system) Guided Fault Finding of the A/C control module is to be performed as described using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Different versions depending on vehicle equipment (with and without Driver Heated Seat Adjuster -E94- and Front Passenger Heated Seat Adjuster -E95-). Removing and installing, refer to «HEATER CONTROLS»(ref-496069-S20638973832012082100000) . Function, electrical testing and activation of heated rear window, heated seats, etc. by (A/C control module), check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function. NOTE: Beginning with MY 2009, as a running change, seat heating control modules are being installed, whereby the specified temperature for the seat heating is controlled by a lower characteristic line. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. If the vehicles has a manual climate control system, then, depending on the setting on the A/C control module (for example, the heater is on) the Stop function will prevent the engine from being started again as soon as there is a request for heating. In cooling mode, the Stop function is not limited by the A/C control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the vehicle has the Start/Stop System, there is no additional coolant pump. An electric coolant pump may be present depending on the vehicle engine, which is controlled by an engine control module. Refer to «GENERAL INFORMATION»(ref-496029-S17085270722012082100000) and refer to «COOLANT PUMP AND COOLANT THERMOSTAT ASSEMBLY OVERVIEW»(ref-496039-S06878524212012082100000) and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the vehicle has a Start/Stop System and a manual climate control system, then install A/C control module, part number 8P0 820 047, starting with index D. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with the Start/Stop System, seat heating is switched off whenever the Stop function is active (by the Vehicle Electrical System Control Module -J519- to protect the battery). After the engine is started again by the Start function, seat heating is switched on again. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
12. Interior Temperature Sensor Fan -V42- Not installed on vehicles with manually regulated A/C system. Installed in Climatronic control module. Interior Temperature Sensor Fan, removing and installing, refer to «INTERIOR TEMPERATURE SENSOR FAN»(ref-496031-S25199706692012082100000) .
13. Instrument Panel Interior Temperature Sensor -G56- Not installed on vehicles with manually regulated A/C system. Installed in the Climatronic control module, cannot be replaced individually.

Scheme 20

1. Right Front Seat Temperature Sensor -G345- and Right Front Heated Seat -Z46- Seat heater is not installed in all vehicles (optional equipment). Vehicles with automatically regulated A/C system: activation of seat heater is displayed in measured value block of Climatronic Control Module -J255-, check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Vehicles with manually regulated A/C system: function and activation of seat heater, check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Seat heating, servicing, refer to «Removal and Installation»(ref-496130-S14637100472012082100000) . NOTE: From MY 2009, as a running change, the Climatronic control module, (or control modules for seat heating) is being installed, whereby the specified temperature is set to a lower characteristic line. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
2. Right Footwell Vent Removing and installing vent, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
3. Right Vent Temperature Sensor -G151- Not installed on vehicles with manually regulated A/C system. Removing and installing, refer to «RIGHT VENT TEMPERATURE SENSOR»(ref-496031-S33298080902012082100000) .
4. Evaporator Drain Hose Checking, removing and installing, refer to «CONDENSATE DRAIN HOSE»(ref-496031-S18551473692012082100000) .
5. Sunlight Photo Sensor -G107- Not installed on vehicles with manually regulated A/C system. Removing and installing, refer to «SUNLIGHT PHOTO SENSOR»(ref-496031-S34459175392012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
6. Cover for Loudspeaker in Center Instrument Panel Removing and installing cover, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
7. Defroster Vent For front windshield. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
8. Light Emitting Diode for Central Locking System Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
9. A/C Unit With Evaporator and Add-On Components Air guide in air conditioner and in vehicle, refer to «AIR GUIDE IN AIR DISTRIBUTION HOUSING»(ref-496031-S27360377282012082100000) . Components of heating and A/C unit in passenger compartment, refer to «HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED»(ref-496031-S10151584442012082100000) or «HEATING A/C UNIT COMPONENTS - AUTOMATICALLY REGULATED»(ref-496031-S32139001312012082100000) . Clean air conditioning system evaporator with Ultrasound A/C Cleaner VAS 6189A, refer to «A/C EVAPORATOR CLEANING»(ref-496031-S30008453562012082100000) . Heating and A/C unit, removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) .
10. Defroster Vent Side window/passenger side. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
11. Instrument Panel Vent, Right Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .

AIR GUIDE IN AIR DISTRIBUTION HOUSING

Note. To illustrate air guide in the air distribution housing, it is shown in the form of sectional views A - A and B - B.

Scheme 21

1. Air Distribution Housing
2. Left Temperature Door (Driver Side) Vehicles with manually regulated A/C system, right and left temperature doors are connected to each other via the shaft and are moved together by Temperature Regulator Door Motor -V68-. Shown in the cooling position.
3. Air Guide To Air Guide Channel To Vent In Rear Center Console and To Center Instrument Panel Vents
4. Air Guide To Air Guide Channel To Vent In Rear Center Console and To Center Instrument Panel Vents
5. Right Temperature Door (Front Passenger Side) Vehicles with manually regulated A/C system, right and left temperature doors are connected to each other via the shaft and are moved together by Temperature Regulator Door Motor -V68-. Shown in center position.
6. Left Footwell Door (Driver Side) Shown in closed position. Vehicles with automatically regulated A/C system: central doors (left, right and center) and both footwell doors are operated with each other via curved washers installed on control motor or on shaft. Vehicles with manually regulated A/C system: doors are operated via a flexible shaft and a curved washer, refer to «HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED»(ref-496031-S10151584442012082100000) .
7. Air Guide Channel In The Driver Side Footwell
8. Air Distribution Housing Sectioned Above Line A - A
9. Auxiliary Air Heater Heating Element -Z35- (with Auxiliary Air Heater Control Module -J604-) Not installed in all vehicles. Installed only on diesel vehicles; depending on the vehicle equipment level, the vehicle may have an electric auxiliary heater or a fuel driven auxiliary heater. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (and for each engine control module).
10. Heat Exchanger For Heater Unit
11. Air Outlet From Evaporator Housing
12. Right Temperature Door (Front Passenger Side) Vehicles with manually regulated A/C system, right and left temperature doors are connected to each other via the shaft and are moved together by Temperature Regulator Door Motor -V68-. Shown in center position.
13. Right Footwell Door (Front Passenger Side) Shown in closed position. Vehicles with automatically regulated A/C system: central doors (left, right and center) and both footwell doors are operated with each other via curved washers installed on control motor or on shaft. Vehicles with manually regulated A/C system: doors are operated via a flexible shaft and a curved washer, refer to «HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED»(ref-496031-S10151584442012082100000) .
14. Defroster Door Shown in closed position. NOTE: The change to the door has no influence on the A/C controls on vehicles with manual A/C (without automatic A/C) (the door is controlled only when the manual A/C is adjusted). On vehicles with an automatic A/C, the Climatronic Control Module -J255- was already changed at the end of MY 2007. The Climatronic control module, part number 8P0 820 043 beginning with index AE can be entered, via the "adaptation", and the version of the door in the air outlet to the defroster vents in the instrument and number of control motors on the A/C unit (with and without Back Pressure Door Motor -V71-) using (Climatronic control module) Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
15. Air Distribution Housing Sectioned Above Line B - B
16. Central Door - Center Shown in open position. Vehicles with automatically regulated A/C system: central doors (left, right and center) and both footwell doors are operated with each other via curved washers installed on control motor or on shaft. Vehicles with manually regulated A/C system: doors are operated via a flexible shaft and a curved washer, refer to «HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED»(ref-496031-S10151584442012082100000) .
17. Door In Air Guide Channel To Air Guide To Vent In Center Console At Rear This door is controlled by the lever attached to the center of the central door.
18. Air Guide Channel To The Air Guide For The Rear Center Console Vents This channel is currently sealed with a plug. Introduction of a vent in the rear center console has not yet been finalized.

Scheme 22

1. Fresh Air Intake
2. Removing Air From The Passenger Compartment (For Recirculating Air Mode)
3. Outlet To Right Front Footwell Vent
4. Outlet To Right Instrument Panel Vent
5. Outlet To Center Instrument Panel Vents (Left And Right)
6. Outlet To Left Instrument Panel Vent
7. Outlet To Left Front Footwell Vent
8. Outlet To Defroster Vents (Instrument Panel)
9. Outlet To Right Rear Footwell Vent
10. Outlet To Left Rear Footwell Vent
11. Outlet To Vent In Rear Center Console Currently sealed with a plug. Introduction of a vent in center console has not yet been finalized.
12. Outlet To Vent In Rear Center Console Currently sealed with a plug. Introduction of a vent in center console has not yet been finalized.

AIR QUALITY SENSOR FUNCTION

1. The Air Quality Sensor -G238- detects the pollutants in the surrounding air (mostly gasoline and/or diesel exhaust gases) and switches the Climatronic Control Module -J255- to recirculating air mode.
2. Climatronic control module detects the type and intensity of air pollution at signal from the Air Quality Sensor. Depending on the outside temperature and the intensity of air pollution, the Climatronic control module then decides

At an outside temperature greater than approximately +2 °C (36 F) the recirculating air mode is switched on when there is only a slight increase in pollutants in the ambient air.

At an outside temperature between approximately +2 °C and approximately -8 °C, the change over to recirculating air mode only occurs at a sharp increase of pollutant concentration, during which the compressor is switched on simultaneously.

At an outside temperature less than approximately -8 °C, the change over still occurs only at a sharp increase of pollutant concentration and then only for approximately 15 seconds (compressor is not switched on).

If the pollution concentration in ambient air drops, the climate control system switches over to the fresh air mode.

1. Automatic recirculating air mode can be switched off at any time. If the function is active, the A/C compressor is switched on with a request for automatic recirculating air mode and also when the outside air temperature is below +2 °C. If the temperature is below -8 °C, then it is not possible to sue the A/C compressor.
2. At setting automatic air recirculation on Climatronic control module, compressor can be switched on also by switching on recirculating air manually (via recirculating air button Umluft ) up to a temperature of approximately -8 °C
3. To ensure that the A/C does not operate constantly in the recirculating air mode in areas with a consistently higher pollution, the sensor is self learning (it adjusts its sensitivity to the environmental conditions).
4. If outside air pollution load remains high for longer period of time, the sensor starts to adapt itself to the changing environmental condition through an adaptation program (learning program), the air recirculation request in evenly polluted ambient air is therefore generally shorter than 12 minutes. If a succession of peaks in the polluted air is detected, the air conditioning system can operate over a longer period of time in recirculated air mode.
5. A certain amount of time is required for repositioning of the air conditioning system doors. In the event that a sudden increase in pollutants is encountered (e.g. when driving through a diesel exhaust cloud) gaseous pollutants can be taken in with the fresh air into the passenger compartment until the door can be closed. For this reason, a dust and pollen filter is installed with a charcoal layer. A filter that is saturated with pollutants is no longer effective and needs to be replaced, refer to «DUST AND POLLEN FILTER»(ref-496031-S36991706242012082100000) .
6. In order to avoid frequent shifting of the fresh /recirculating air doors, a slight increase of pollutants in the ambient air will not allow for immediate shifting (the sensor does not send a request to Climatronic control module). The filtering of the charcoal insert in the dust and pollen filter will be sufficient, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(ref-496031-S38707390862012082100000) .
7. In order to avoid frequent shifting of the fresh/recirculating air doors, the requirement from the sensor for Automatic air recirculation mode remains for at least 25 seconds (minimum duration period), even if the pollutant concentration is so far reduced that recirculating air mode is no longer necessary.
8. If the A/C compressor is shut-off (e.g. in Econ mode), the maximum duration of the Automatic recirculating air mode is limited to approximately 15 seconds by Climatronic control module to avoid windows from fogging up. Depending on the control head version, Econ is on when the ECON button lights up and the AC is off.
9. So that fogged windows are cleared as quickly as possible, Climatronic control module does not permit recirculating air operation during the Defrost operating mode.
10. After the ignition is switched on, Air Quality Sensor requires approximately 30 seconds to be operational (warm-up time). During this time there is no requirement from the sensor to Climatronic control module for Automatic recirculating air mode.
11. The Air Quality Sensor contains a highly sensitive electronic component which can be damaged if it comes in direct contact with solvents, fuels or chemicals. For this reason, do not install sensors that may have come into contact with these substances.

AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT

Note. Air intake apparatus, air outlet and air guide in A/C unit, refer to AIR GUIDE IN AIR DISTRIBUTION HOUSING . Component locations of individual components, refer to A/C SYSTEM CONTROL AND REGULATION COMPONENTS INSIDE PASSENGER COMPARTMENT , HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED and HEATING A/C UNIT COMPONENTS - AUTOMATICALLY REGULATED . The ventilation of the passenger compartment occurs via two air extraction outlets (in luggage compartment right and left near the bumper), refer to VENT FRAME, CHECKING .

Scheme 23

1. Instrument Panel With air ducts to defroster vents and instrument panel vents driver and passenger side. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
2. Defroster Vent For front windshield. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) . If the Intermediate piece between air conditioner and air duct in the instrument panel has been pinched during installation, the air guide to the front windshield is uneven or insufficient. «Removal and Installation»(ref-496058-S22585871132012082100000) .
3. Defroster Vent Side window/passenger side. Removing and Installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
4. Instrument Panel Vent, Right Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
5. Right Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
6. Left Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
7. Instrument Panel Vent, Left Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(ref-496031-S35281215092012082100000) and «Removal and Installation»(ref-496058-S22585871132012082100000) .
8. Defroster Vent Side window/driver side. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
9. Intermediate Piece / Defrost Canal Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
10. Fresh Air Intake Air is drawn in via plenum chamber.
11. Recirculating Air Intake The air is taken from the passenger footwell under the glove compartment.
12. Air Guide/Instrument Panel Vent To center vents at left and right. Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
13. Right Front Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
14. Trim Panel For Right Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
15. Air Duct To Rear Right Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
16. Air Guide To Vent In Rear Center Console Only in vehicles with vent installed in center console (introduction not yet finalized). Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
17. Plug Only in vehicles without air guide to vent installed in center console at rear.
18. Air Duct To Rear Left Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
19. Trim Panel For Left Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
20. Left Front Footwell Vent Removing and installing, refer to «Removal and Installation»(ref-496058-S22585871132012082100000) .
21. Air Conditioner Unit Heating and A/C unit, removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . From November 2007, a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed, refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(ref-496031-S04262121652012082100000) . NOTE: The change to the door in the air vent to the defroster vent has no influence on the A/C controls on vehicles with manual A/C (without automatic A/C) (the door is controlled only when the manual A/C is adjusted). On vehicles with an automatic A/C, the Climatronic Control Module -J255- was already changed at the end of MY 2007. The Climatronic control module, part number 8P0 820 043 beginning with index AE can be entered, via the "adaptation", and the version of the door in the air outlet to the defroster vents in the instrument and number of control motors on the A/C unit (with and without Back Pressure Door Motor -V71-) (Climatronic control module) using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Note. Not installed on vehicles with manually regulated A/C system. The Climatronic Control Module -J255- currently can be interchanged; the component protection is not in effect. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If a Climatronic control module with active component protection (anti-theft system, introduction not yet finalized) is installed in a different vehicle, only the functions necessary for vehicle safety can be selected, Comfort functions can no longer be selected. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Component protection (anti-theft system, introduction not yet finalized) can only be cancelled by entering specific vehicle data using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Climatronic control module may also be designated only Climatronic Control Module -J255- in the wiring diagrams. Use the correct allocation when replacing the Climatronic control module. Different versions of the Climatronic control module in vehicles with an Air Quality Sensor -G238- (with a button for automatic air recirculation -C- or a button for switching off climate controls OFF button), with and without controls for heated seats, with and without radio navigation system (or radio with large control panel). Part number index must therefore be heeded. In a Climatronic control module for vehicles with an Air Quality Sensor (with a button for automatic air recirculation -C-), A/C system controls can be switched off by pressing blower - button again at a fresh air blower speed set to one bar (indication on display). Refer to the Owner's Manual. After installing Climatronic control module, perform Basic Setting for A/C system according to specifications using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If a new Climatronic control module was installed and Basic Setting was not performed, controls of the Climatronic control module are restricted and this is displayed as a malfunction in DTC memory. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Display fields and control buttons on Climatronic control module are illuminated by Light Emitting Diodes (LEDs, cannot be replaced). Covers of both temperature rotary switches of Climatronic control module can be replaced separately (pull off to remove). If Instrument Panel Interior Temperature Sensor -G56- sends incorrect measurements, check intake grille on panel of Climatronic control module (it must not be sealed) and function of Interior Temperature Sensor Fan -V42-. The selected functions are displayed by illuminated LEDs in the various buttons of the Climatronic control module. After replacing Climatronic control module, perform the follow work steps: Checking the DTC memory, performing a basic setting, coding and adapting using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function. Displayed unit of temperature display of Climatronic control module (in °C or °F) is specified by the coding. Change the display units as follows: with the ignition turned on, press and hold the air recirculation -A- button. With the air recirculation button pressed in, rotate the left temperature rotary switch -B- (driver side) to temperature + position and hold it in this position for at least 2 seconds. Temperature display changes from °C or F ° or vice versa. Release temperature rotary switch and recirculating air button. Temperature setting on driver side can be transferred to front passenger side by pressing "Auto" button for longer than approximately 5 seconds. This setting can then be changed together for both sides by operating the left temperature rotary switch -B- (driver side), this setting can be cancelled again by operating the right temperature rotary switch (front passenger side) once. Refer to Owner's manual. On vehicles equipped with an auxiliary heater, depending on the adaptation, the Climatronic control module can be switched on by using the Fan + button with the ignition switched off or the parking ventilation. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and Owner's Manual. On vehicles with parking heater and Climatronic control module with Part No. 8P0 820 043 up to Index Q (hardware version up to H18 and software version up to 0260), it is possible that the setting on the Climatronic control module can no longer be modified under certain operating conditions after parking heater has started. After switching the ignition off and on again, the settings can be modified again as normal. If there is a complaint of this malfunction, flash the software of Climatronic control module anew if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

1. Climatronic control module, removing and installing, refer to «CLIMATRONIC CONTROL MODULE»(ref-496031-S15917913952012082100000) .
2. Installation time for the different versions of the Climatronic control module refer to «CLIMATRONIC CONTROL MODULE»(ref-496031-S17835821392012082100000) .

DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT

1. Dust and pollen filter with additional filter element with activated charcoal is installed at this time in vehicles with or without A/C system (only with heater). In vehicles with automatically regulated A/C system, an Air Quality Sensor -G238-, refer to ( «AIR QUALITY SENSOR FUNCTION»(ref-496031-S11723876312012082100000) ) may also be installed (currently as optional equipment).
2. The activated charcoal filter element continues to function as a dust and pollen filter, however in addition the activated charcoal filter can also filter out gaseous pollutants e.g. ozone, benzene, nitrogen dioxide from the air flow.
3. The task of the active carbon filter element is to store (catch) the gaseous pollutants of the incoming air, until the back pressure door (fresh air door) is closed and the climate control system operates in recirculating mode. The change over from fresh to recirculating mode occurs via the Climatronic Control Module -J255-, as soon as air quality sensor detects gaseous pollutants in the ambient air (the automatic air recirculation mode must be selected).
4. The activated charcoal layer in the dust and pollen filter reacts differently to various pollutants in the air.

Certain pollutants bond permanently in the active-carbon layer.

Others are converted into noxious bonds like in a catalytic converter.

For the rest the activated charcoal works as a condenser (capacitor). With increasing load pollutants are absorbed, until a certain saturation is reached. If the amount of pollutants decreases, the activated charcoal layer continuously releases the absorbed particles.

1. Under the following operating conditions the dust and pollen filter must be replaced earlier than required, because a certain amount of pollutant particles is permanently bonded to the activated charcoal layer.

If vehicle is driven in areas with strong air pollution.

If vehicle is predominantly driven with the automatic recirculating air mode switched off.

1. If possible, vehicles with A/C system with one air quality sensor should always be operated in automatic air recirculation mode. However, if it is desired or necessary to switch this mode off, the following must be observed

The active carbon layer in the dust and pollen filter is saturated after a certain time.

A saturated filter can no longer absorb pollutants and the pollutants can flow through freely.

1. The most important task of the dust and pollen filter and air quality sensor is keep the load peaks out from the passenger compartment. For this the following must be observed

If a vehicle is driven in an area with relatively clean air (with little air pollution), the system will switch from fresh air mode to recirculation mode occurs at a different point in time than when in an area with heavy air pollution (such as an industrial area).

Independently of the basic load, the change-over from fresh to recirculating mode always occurs, when the pollutant-load increases (e.g. when driving to through an exhaust cloud of a Diesel truck).

HEATING AND A/C UNIT COMPONENTS - MANUALLY REGULATED

Note. The design of the heating and A/C unit is largely the same on vehicles with manually and automatically regulated A/C systems, the differences can be found in the operation of the doors, in Fresh Air Blower -V2- and in the number and version of the motors.

Observe notes for control and regulation of components in passenger compartment. Refer to A/C SYSTEM CONTROL AND REGULATION COMPONENTS INSIDE PASSENGER COMPARTMENT .

Note. Air duct in air conditioner and in vehicle AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT . Heating A/C unit, removing and installing, refer to HEATING AND A/C UNIT .

Scheme 24

1. A/C Unit With Evaporator Different versions of heating A/C unit in vehicles with manually and automatically regulated A/C system. May only be removed when refrigerant circuit has been removed; bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) . Heating A/C unit, removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . A/C unit, disassembling and assembling, refer to «A/C UNIT»(ref-496031-S16484800142012082100000) . Clean air conditioning system evaporator with Ultrasound A/C Cleaner VAS 6189A, refer to «A/C EVAPORATOR CLEANING»(ref-496031-S30008453562012082100000) .
2. A/C System Controls / Base Plate Different versions of base plate on vehicles with manually regulated A/C system and without A/C system (with heating system only). Removing and installing, refer to «HEATER CONTROLS»(ref-496069-S20638973832012082100000) .
3. A/C Control Module -J301- Different versions depending on vehicle equipment (with and without Driver Heated Seat Adjuster -E94- and Front Passenger Heated Seat Adjuster -E95-). Removing and installing, refer to «HEATER CONTROLS»(ref-496069-S20638973832012082100000) . Function, electrical test, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
4. Heat Exchanger For Heater Unit Removing and installing, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
5. Temperature Regulator Door Motor -V68- With Temperature Regulator Door Motor Position Sensor -G92-. Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE / TEMPERATURE REGULATOR DOOR MOTOR»(ref-496031-S18972377132012082100000) . The name for this control motor in Guided Fault Finding and in the wiring diagram is different on vehicles with a manually and an automatically regulated A/C system, refer to the appropriate SYSTEM WIRING DIAGRAMS information. On vehicles with manually regulated A/C system, this control motor operates both temperature doors (the right and left temperature doors are connected to each other via the shaft). On vehicles with an automatically regulated A/C system, the left and right temperature doors are each actuated by one control motor.
6. Left Footwell Vent Temperature Sensor -G261- This sensor is installed only at beginning of production (discontinued as running change). Measured value of this sensor is not evaluated by the A/C control module, a malfunction at left footwell vent temperature sensor is not detected. Removing and installing, refer to «LEFT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S38962577942012082100000) .
7. Auxiliary Air Heater Heating Element -Z35- (with Auxiliary Air Heater Control Module -J604-) The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the auxiliary air heater heating element via the auxiliary air heater control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. On diesel vehicles built from November 2006 (running change) have a 3-stage Auxiliary Air Heater Heating Element which is controlled by a relay from the Engine Control Module (ECM). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an Auxiliary Air Heater Heating Element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the Auxiliary Air Heater Heating Element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Check the function of the auxiliary air heater control module, perform Guided Fault Finding using Vehicle Diagnosis, Testing and Information System VAS 5051. Removing and installing, refer to «AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE»(ref-496031-S23889843062012082100000) .
8. Flexible Shaft To gear mechanism with curved washer for activation of air distribution doors. Removing and installing, refer to «AIR DISTRIBUTION FLEXIBLE SHAFT»(ref-496069-S22647833952012082100000) .
9. To Gear Mechanism With Curved Washer For Activation Of Air Distribution Doors Do not remove, adjustment cannot be reproduced.
10. Recirculation Door Motor -V113- Different versions of recirculation door motor in vehicles with manually and automatically regulated A/C system. On version for manually regulated A/C system, the recirculation door motor does not have potentiometer installed, therefore this motor is always actuated in one direction (fresh air or recirculated air mode). The direction of control motor rotation is reversed by interchanging the Plus and Minus on the outputs of A/C Control Module -J301-. The A/C control module detects via the current strength, which flows via the control motor, that is has reached its end position. The recirculation door motor does not have a potentiometer, therefore a malfunction at the control motor or in its wire connection is not always detected by A/C control module. Checking function using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(ref-496069-S25088012372012082100000) .
11. Intake Housing With Fresh/Recirculating Air Door Different versions of the air intake shroud in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «AIR INTAKE HOUSING WITH FRESH/RECIRCULATING AIR DOOR»(ref-496069-S35754411122012082100000) .
12. Fresh Air Blower -V2- Different versions of Fresh Air Blower in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM»(ref-496069-S28855578172012082100000) .
13. Fresh Air Blower Series Resistor With Fuse -N24- Removing and installing, refer to «FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM»(ref-496069-S25399057542012082100000) .
14. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(ref-496031-S36991706242012082100000) . Follow the replacement intervals, refer to «Maintenance, Diagnosis»(ref-496015-S28841274602012082100000) . As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element). For information regarding for version with an activated charcoal insert, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(ref-496031-S38707390862012082100000) .
15. 10-pin Connector To vehicle wiring harness, refer to the appropriate SYSTEM WIRING DIAGRAMS information.
16. Evaporator Vent Temperature Sensor -G263- Removing and installing, refer to «EVAPORATOR VENT TEMPERATURE SENSOR»(ref-496031-S28737448952012082100000) .
17. Coolant Pipes To Heater Core
18. Grommet For sealing off opening for coolant and refrigerant lines through bulkhead to engine compartment. A foam spacer bracket is installed between grommet and heating A/C unit. Installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) .
19. Condensation Water Drain Connection Condensation water drain valve, checking, removing and installing, refer to «CONDENSATE DRAIN HOSE»(ref-496031-S18551473692012082100000) .
20. Expansion Valve Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE»(ref-496031-S08812543432012082100000) . Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) . NOTE: After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.

HEATING A/C UNIT COMPONENTS - AUTOMATICALLY REGULATED

Note. The design of the heating A/C unit is largely the same on vehicles with manually and automatically regulated A/C systems, the differences can be found in the operation of the doors, in Fresh Air Blower -V2- and in the number and version of the motors.

Observe notes for control and regulation of components in passenger compartment. Refer to A/C SYSTEM CONTROL AND REGULATION COMPONENTS INSIDE PASSENGER COMPARTMENT .

Note. Air duct in air conditioner and in vehicle AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT . Heating A/C unit, removing and installing HEATING AND A/C UNIT .

Scheme 25

1. A/C Unit With Evaporator May only be removed when refrigerant circuit has been removed; bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) . Heating and A/C unit, removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . Heating and A/C unit, disassembling and assembling, refer to «A/C UNIT»(ref-496031-S16484800142012082100000) . Clean air conditioning system evaporator with Ultrasound A/C Cleaner VAS 6189, refer to «A/C EVAPORATOR CLEANING»(ref-496031-S30008453562012082100000) .
2. Defroster Door Motor -V107- With Defroster Door Motor Position Sensor -G135-. Lever color identification: blue. Removing and installing, refer to «DEFROSTER DOOR MOTOR»(ref-496031-S20716524382012082100000) . NOTE: This motor is fastened on the right on air distributor housing in vehicles with right-side steering.
3. Left Footwell Vent Temperature Sensor -G261- Removing and installing, refer to «LEFT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S38962577942012082100000) .
4. Central Air Door Motor -V70- With Central Door Motor Position Sensor -G112-. Removing and installing, refer to «CENTRAL AIR DOOR MOTOR»(ref-496031-S11886634592012082100000) .
5. Auxiliary Air Heater Heating Element -Z35- with Auxiliary Air Heater Control Module -J604- The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the auxiliary air heater heating element via the auxiliary air heater control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. On diesel vehicles built from November 2006 (running change) have a 3-stage Auxiliary Air Heater Heating Element which is controlled by a relay from the Engine Control Module (ECM). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and Refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an Auxiliary Air Heater Heating Element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the Auxiliary Air Heater Heating Element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Check the auxiliary air heater control module, perform Guided Fault Finding using Vehicle Diagnosis, Testing and Information System VAS 5051. Removing and installing, refer to «AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE»(ref-496031-S23889843062012082100000) .
6. Heat Exchanger For Heater Unit Removing and installing, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
7. Left Temperature Door Motor -V158- With Left Temperature Door Potentiometer/Actuator -G220-. Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE / TEMPERATURE REGULATOR DOOR MOTOR»(ref-496031-S18972377132012082100000) . The name for this control motor in Guided Fault Finding and in the wiring diagram is different on vehicles with a manually and an automatically regulated A/C system, refer to the appropriate SYSTEM WIRING DIAGRAMS information. On vehicles with manually regulated A/C system, this control motor operates both temperature doors (the right and left temperature doors are connected to each other via the shaft). On vehicles with an automatically regulated A/C system, the left and right temperature doors are each actuated by one control motor.
8. Airflow Door Motor -V71- With Back Pressure Door Motor Position Sensor -G113-. Removing and installing, refer to «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . NOTE: To the end of model year 2007, the Air Flow Door Motor -V71- is being discontinued as a running change, on vehicles without the Air Flow Door Motor the air flow door (fresh air door) is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) . Therefore note the correct allocation of the Climatronic Control Module -J255-, if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
9. Recirculation Door Motor -V113- With Recirculation Door Motor Position Sensor -G143-. Removing and installing, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) . Different versions of recirculation door motor in vehicles with manually and automatically regulated A/C system. Different versions of recirculation door motor on vehicles with automatically regulated A/C system, with and without back pressure door motor (see item 7).
10. Right Footwell Vent Temperature Sensor -G262- Removing and installing, refer to «RIGHT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S24526980612012082100000) .
11. Intake Housing With Recirculating Air Back Pressure Door (Fresh Air Door) Removing and installing, refer to «AIR INTAKE HOUSING»(ref-496031-S31791968262012082100000) .
12. Fresh Air Intake Duct Temperature Sensor -G89- Removing and installing, refer to «FRESH AIR INTAKE DUCT TEMPERATURE SENSOR»(ref-496031-S34189917812012082100000) . NOTE: From model year 2006, the Fresh Air Intake Duct Temperature Sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic Control Module -J255- with part no. as of index M is or may be installed. On vehicles without Fresh Air Intake Duct Temperature Sensor, a Climatronic control module with part no. up to index L installed enters a DTC into the DTC memory.
13. Fresh Air Blower Control Module -J126- and Fresh Air Blower -V2- Removing and installing, refer to «FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM»(ref-496031-S01188964712012082100000) . Different versions, as of model year 2007 the Fresh Air Blower Control Module and Fresh Air Blower can each be replaced separately (running change in production), refer to «FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM»(ref-496031-S01188964712012082100000) . Fresh Air Blower Control Module is installed in Fresh Air Blower. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
14. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(ref-496031-S36991706242012082100000) . Follow the replacement intervals, refer to «Maintenance, Diagnosis»(ref-496015-S28841274602012082100000) . As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element). For information regarding for version with an activated charcoal insert, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(ref-496031-S38707390862012082100000) .
15. Evaporator Vent Temperature Sensor -G263- Removing and installing, refer to «EVAPORATOR VENT TEMPERATURE SENSOR»(ref-496031-S28737448952012082100000) .
16. Right Temperature Door Motor -V159- With Right Temperature Door Potentiometer/Actuator -G221-. Removing and installing, refer to «RIGHT TEMPERATURE DOOR MOTOR»(ref-496031-S09255170142012082100000) .
17. Coolant Pipes To Heater Core
18. Grommet For sealing off opening for coolant and refrigerant lines through bulkhead to engine compartment. A foam spacer bracket is installed between grommet and heating A/C unit. Installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) .
19. Condensation Water Drain Connection Condensation water drain valve, checking, removing and installing, refer to «CONDENSATE DRAIN HOSE»(ref-496031-S18551473692012082100000) .
20. Expansion Valve Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE»(ref-496031-S08812543432012082100000) . Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) . NOTE: After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.

A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL

Special tools and workshop equipment required

1. Connector Test Set V.A.G 1594 C
2. Vehicle Diagnostic, Testing and Information SystemVAS 5051 A with DSO Measuring Leads 1 2 VAS 5051/8

Note. The test for an A/C compressor manufactured by Denso of type 7 SEU 16 is described in the following. Test is to be performed in the same way for vehicles with a different compressor type or a different manufacturer.

Switch off ignition.

Remove the engine cover (for example, connector is accessible from top in vehicles with 4-cylinder engine), refer to ENGINE COVER WITH AIR FILTER ELEMENT .

Remove the noise insulation (for example, on vehicles equipped with a 4-cylinder, 2.0L TFSI engine or a 6-cylinder engine; on these engines, the connector is not accessible from the top). Refer to Removal and Installation .

Disconnect electrical connection to A/C Compressor Regulator Valve -N280- at the connector -1-.

Scheme 26

Reproduce the connection between connector -A- and connector -B- at regulator valve using an adapter cable from V.A.G 1594 C.

Scheme 27

Note. Vehicles with automatically regulated A/C system, the Climatronic Control Module -J255- actuates the compressor via the A/C compressor regulator valve. The A/C Control Module -J301- controls the A/C compressor via the A/C compressor regulator valve on vehicles with a manual climate control system. The A/C compressor regulator valve control and the measured current from the Climatronic control manual or from the A/C control module that flows via the A/C compressor regulator valve is displayed in the A/C control module measured values block using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. An adapter cable can also be used for this test. To do this, e.g. use connectors -A- and -B- (part number 1J0 973, 702 and 1J0 973, 802 and relevant terminal contacts), two standard sockets for banana connectors -C- and two wires with 0.5 mm 2 diameter.

Connect VAS 5051/8 to the adapter leads.

Measuring lead (signal wire) to terminal -2- on connector -A

Measuring lead (shielding, ground) to terminal -1- of connector -A

In VAS 5051 A, select operating mode Test Instruments: DSO (Digital Storage Oscilloscope) and select setting 5V / Div = 0.5.5ms / Div (5V DC voltage and 5 milliseconds per unit)

Start the engine.

Vehicles with automatically regulated A/C system: set temperature preselect for driver and front passenger side to Lo on Climatronic control module.

Vehicles with a manual climate control system: turn temperature preselect rotary switch on A/C Control Module counter-clockwise to the Cold stop.

On the control head, switch the Climatronic control module by pressing the Auto and Off/On buttons or the Econ or AC buttons on and off to control the A/C Compressor Regulator Valve (vehicles with automatic A/C).

Note. Depending on the control module, Econ is on when the ECON button lights up and the AC is off.

Vehicles with manually regulated A/C system: switch the activation of A/C Compressor Regulator Valve on and off via the AC button on A/C control module.

Shown on screen of oscilloscope, depending on setting of Climatronic control module

No square wave signal (regulator valve is not activated) for operating mode OFF or Econ (AC off).

A square wave signal with an impulse width -A- between 75% and 100% (regulator valve is activated) for operating mode Auto (AC on) and temperature setting Lo (temperature rotary switch at cold stop).

Scheme 28

Note. The Fig. shows a signal with a duty cycle of approximately 80%. Impulse width -A- is dependent on desired cooling performance, vehicle voltage etc. (over the width of region -A-, voltage is regulated via A/C Compressor Regulator Valve by Climatronic control module / by A/C control module). The signal distance -B- is always 2 milliseconds. This corresponds to frequency of 500 Hertz. The duty cycle is determined by the ratio of impulse width -A- and signal distance -B-.

The impulse width of the square wave signal changes (duty cycle between 100% and greater than 30%, regulator valve is activated so that required compressor output is obtained to reach the specified temperatures) depending on setting at Climatronic Control Module / at A/C Control Module and measured surrounding conditions.

Note. With the Auto button pressed and the temperature set to Lo (AC on and the temperature rotary switch turned to cold manual climate control system), the A/C compressor regulator valve makes sure that the maximum permissible current of 065 A is flowing via the A/C compressor regulator valve (maximum A/C compressor performance). In control mode, actuation time is governed by required cooling output and vehicle electrical system voltage, for example. It is however always of sufficient duration to achieve a mean current of 0.3 A.

A/C CONTROL MODULE AND AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION

Special tools and workshop equipment required

1. Test Box 105 Pin V.A.G 1598/42-1 and Test Adapter V.A.G 1598/47
2. Voltage Tester V.A.G 1527 B

Remove the glove compartment. Refer to Removal and Installation .

Remove A/C Control Module -J301-, refer to HEATER AND A/C SYSTEM CONTROLS .

Connect the A/C control module to vehicle wiring harness via V.A.G 1598/47.

Connect V.A.G 1598/42-1 to V.A.G 1598/47.

Switch ignition on.

Turn rotary switch for air distribution -B- into air distribution to instrument panel vents position.

Scheme 29

Fresh/recirculating air button -F- is not operated (fresh air mode, button indicator lamp does not light up).

Scheme 30

Connect a V.A.G 1527 B to the V.A.G 1598/47 between terminals 9 and 10 (connector -C-).

Scheme 31

Operate fresh/recirculating air button (button indicator lamp lights up).

Ground (GND) is applied at terminal 9 for a short time and B+ is applied at terminal 9 for a short time.

Note. B+ is applied only for a certain time period after operating the fresh/recirculating air button, when this time has elapsed the control motor is only still actuated over a certain duty cycle (lamp in V.A.G 1527 B only continues to blink on briefly). The illustration above shows the arrangement for testing on a vehicle without A/C system, disregard connector -A- (in magnified area) and V.A.G 1527 B -B- on vehicles with A/C system.

Operate fresh/recirculating air button -F- (recirculating air, button indicator lamp goes out).

Note. By pressing fresh/recirculating air button -F-, A/C Control Module changes the voltage supply to Recirculation Door Motor -V113- (B+ and GND are interchanged).

Check voltage at connector -C- between terminals 9 and 10 e.g. using V.A.G 1527 B -B- (to Fresh/Recirculating Air Door Motor -V154-).

Ground is applied at terminal 10 for a short time and B+ is applied at terminal 9 for a short time.

Recirculation Door Motor -V113- and thus the recirculation door moves into fresh air mode position (recirculating air intake opening -C- is closed).

If no malfunction is detected during this test

Check fresh/recirculating air door for freedom of movement.

Replace the air recirculation door motor. Refer to FRESH/RECIRCULATION AIR DOOR MOTOR .

The function is not OK

Check wire connection between A/C control module and Recirculation Door Motor for open circuit or short circuit. Refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Check voltage supply and Ground (GND) connection to A/C control module.

Replace A/C control module, refer to HEATER CONTROLS .

AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION

Special tools and workshop equipment required

1. Voltage tester V.A.G 1527 B

Remove the glove compartment, if necessary. Refer to Removal and Installation .

Switch ignition on.

Set switch for Fresh Air Blower -V2- -G- to speed 3.

Turn rotary switch for air distribution -B- into air distribution to instrument panel vents position.

Fresh/recirculating air button -F- is not operated (fresh air mode, button indicator lamp does not light up).

1. Air is drawn in via fresh air intake from plenum chamber.

Operate fresh/recirculating air button -F- (recirculating air, button indicator lamp lights up).

1. Air is drawn in from area behind glove compartment (recirculating air mode).

Turn rotary switch for air distribution -B- into air distribution to front windshield position -D-.

1. Indicator lamp in fresh/recirculating air button -F- goes out, fresh/recirculating air door goes into fresh air mode position.

Note. If function is not OK, check electronics in A/C Control Module -J301- and activation of Recirculation Door Motor -V113-, refer to A/C CONTROL MODULE AND AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION . The Air Recirculation Mode function is erased automatically after approximately 20 minutes after switching ignition on again (it remains permanently stored in the Japan coding only). If windows fog up after switching on ignition again, air recirculation mode is to be switched off manually.

If fresh/recirculating air door function is OK and windows fog up, check

Dust and pollen filter for soiling, refer to DUST AND POLLEN FILTER .

Forced air extraction of passenger compartment, refer to VENT FRAME, CHECKING .

Passenger compartment for water penetration.

Fresh air intake from plenum chamber and water drain of plenum chamber, refer to CHECKING AND CLEANING PLENUM CHAMBER WATER DRAIN .

Seals between individual components of fresh air intake and vehicle for damage and proper seal.

Activation of A/C Compressor Regulator Valve -N280- and function of A/C system COOLING PERFORMANCE - WITH AUTOMATICALLY REGULATED A/C SYSTEM, CHECKING or COOLING PERFORMANCE - WITH MANUALLY REGULATED A/C SYSTEM, CHECKING .

Note. Under certain operating conditions, moisture in the refrigerant circuit can lead to ice build-up on the A/C compressor regulator valve (and on the expansion valve). A/C compressor control is reduced by this ice build-up, evaporator is cooled too intensely and freezes. Evaporator ice-up may be the cause for fogged windows.

AIR QUALITY SENSOR, CHECKING

Special tools and workshop equipment required

1. Diagnostic operation system VAS 5051 A with diagnostic cable VAS 5051/5A
2. Commercial gas lighter

Test Prerequisites

1. Vehicle standing in a clean atmosphere (away from running engines, exhaust vents, etc.).
2. Engine compartment and plenum chamber clean (not contaminated with oil or fuel).
3. Engine compartment and plenum chamber not sprayed with cleaning agents or preservatives containing solvents.

Checking

With ignition switched off, connect VAS 5051 A with VAS 5051/5A to the Data Link Connector of vehicle. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Start the engine.

Check DTC memory of Climatronic Control Module -J255- using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Set operating mode "Auto" on Climatronic control module.

Switch on automatic air recirculation function on Climatronic control module.

Wait 30 seconds for the air quality sensor to warm up.

Using the VAS 5051 A select "read measured values block".

Read the air quality sensor measured values.

Note. The operating condition of the fresh/recirculation air door and the condition of the signal from the air quality sensor is displayed in the measured values block of Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

1. Specified value (no request for Recirculating air mode present, air conditioning in fresh air mode)

or

1. Specified value: no request for automatic recirculation mode present, request for partial recirculation mode present (fresh air/recirculating door in the center position)

Remove the Air Quality Sensor G238 from the mount, refer to AIR QUALITY SENSOR .

Allow a little bit of gas from the lighter flow past -B- from the top area -A- of the air quality sensor.

Scheme 32

Note. There are different versions of the air quality sensor, each with different functions. Make sure the allocation is correct. If the air quality sensor comes in contact with cigarette smoke or with gas from an ignitor, it will react since ignitor gas is heavier than air; remove the air quality sensor.

Read the display.

1. Specified value: (request for Automatic air recirculation present, request is fulfilled, A/C switches to recirculating air mode)

Wait a short period time (approximately 1 minute, depending on amount of test gas sprayed on air quality sensor).

Read the display.

1. Specified value (no request for Recirculating air mode present, air conditioning in fresh air mode)

or

1. Specified value: no request for automatic recirculating air mode, request for partial recirculating air mode.

Note. In order to avoid frequent shifting of the fresh/recirculating air doors, the requirement of the air quality sensor for automatic air recirculation mode remains for at least 25 seconds (minimum duration period), even if the pollutant concentration is so far reduced that recirculated air mode is no longer necessary.

Operate switch for wiper/washer system until Windshield Washer Pump -V5- has delivered fluid for approximately 2 seconds.

Read the display.

1. Specified value: (Requirement for recirculating air mode due to washer/wiper system, A/C switches for approximately 10 seconds to the air recirculating mode)

Wait briefly.

Read the display.

1. Specified value: (no request for Recirculating air mode present, air conditioning in fresh air mode)

or

1. Specified value: no request for automatic recirculating air mode, partial recirculating air mode active.

Note. Depending on the composition of the windshield washer fluid, the air quality sensor can determine impurities in the air and request for Automatic air recirculation. If no change-over to the recirculation air mode occurs when the operating switch for the windshield wiper/washer system, check the function (the information "wash windshield" is received via the databus system comfort from the Steering Column Electronic Control Module -J527-) using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function.

If the function of air quality sensor is OK for this test and there is a customer complaint continue as follows

Check dust and pollen filter for dirt, refer to DUST AND POLLEN FILTER .

Connect fault read-out device and select the "Guided Fault Finding " using Vehicle Diagnosis, Testing and Information System VAS5051.

Second person is required to read out values displayed while driving.

Follow the safety instructions from vehicle diagnosis, testing and information system VAS 5051 in the "Guided Fault Finding" function.

Read the air quality sensor measured value using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Start by driving vehicle into an area with a relatively clean atmosphere (system in fresh-air mode).

Then drive vehicle into an area where the atmosphere is polluted (e.g. onto an uphill road with lorry traffic).

Read the displays in the display fields. The display must change, for example when driving through a diesel gas cloud using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Also read and heed descriptions, refer to DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT and AIR QUALITY SENSOR FUNCTION .

AUXILIARY AIR HEATER, CHECKING

Special tools and workshop equipment required

1. Vehicle Diagnosis, Testing And Information System VAS 5051 A

The electric auxiliary air heater is available in different versions (with and without Auxiliary Air Heater Control Module -J604-). Refer to the appropriate SYSTEM WIRING DIAGRAMS information.

1. On vehicles with Diesel engine manufactured up to November 2006 (running change in production), Auxiliary Heater Heating Element -Z35- is activated via the Auxiliary Air Heater Control Module -J604-. Only on these vehicle is it possible to perform Guided Fault Finding on the auxiliary air heater using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
2. On diesel vehicles built from November 2006 (running change) have a 3-stage Auxiliary Heater Heating Element which is controlled by a relay from the Engine Control Module (ECM). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Note. Auxiliary Air Heater Control Module is available in different versions. Pay attention to precise assignment on replacement. The Guided Fault Finding for the auxiliary air heater is to be performed using VAS 5051 A. Auxiliary Air Heater Control Module is installed in Auxiliary Heater Heating Element (cannot be replaced individually). Auxiliary Heater Heating Element is installed in air distribution housing of heating and A/C system, refer to AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE and A/C UNIT . Depending on version of Climatronic control module, individual DTCs possibly cannot always be erased immediately. For these vehicles, switch off ignition and interrupt voltage supply to Climatronic control module (terminal 30 in connector D) for approximately 30 seconds. Depending on version of Climatronic control module, certain settings and codings cannot be transferred immediately. If necessary, lock vehicle and let it stand a minimum of 30 minutes (this allows data bus system to switch into Sleep Mode and once Data bus system awakens these new settings can be transferred).

AUXILIARY HEATER CONTROL, CHECKING

Only installed on vehicles with Diesel engine

The data is exchanged with the Auxiliary Air Heater Control Module -J604-, the Auxiliary Heater Control Module -J364- (of parking heater) or the respective Engine Control Module (ECM) over the CAN-Bus system. Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Note. An electric auxiliary air heater is currently installed in vehicles with diesel engine. In this system, the air is supplied with heat energy after it has left the heater core of the heater / A/C unit, in the event a request from the Climatronic Control Module -J255- / or from the A/C Control Module -J301- is present. Activation of electric auxiliary air heater occurs from Auxiliary Air Heater Control Module or from ECM (on the 3-stage version, via Low Heat Output Relay -J359- and High Heat Output Relay -J360-). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function (Guided Fault Finding for the respective ECM) and refer to the appropriate SYSTEM WIRING DIAGRAMS information. The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the Auxiliary Heater Heating Element -Z35- via the Auxiliary Air Heater Control Module -J604-. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. On vehicles with Diesel engine manufactured later than November 2006 (running change in production), a 3-stage Auxiliary Air Heater Heating Element is installed, which is actuated via a relay by the respective ECM. Refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an Auxiliary Air Heater Heating Element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the Auxiliary Air Heater Heating Element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Functional testing of the electric auxiliary air heater activation on a vehicle with a Auxiliary Air Heater Control Module is described in Guided Fault Finding of the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051. Measuring value block of auxiliary air heater control module indicates that auxiliary heater is switched on or why no activation is occurring despite a request. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Functional testing of the electric auxiliary air heater activation on a vehicle with a 3-stage auxiliary heater heating element is described in Guided Fault Finding of the respective Engine Control Module (ECM) using Vehicle Diagnosis, Testing and Information System VAS 5051. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with the Start/Stop System. the auxiliary heater heating element is switched off when the Stop function is active (to protect the battery). After the engine started with the Start function, the auxiliary heater heating element is switched on again. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". At this time, no auxiliary heater is installed in vehicles with gasoline engine, also the parking heater is not activated as auxiliary heater.

Switch-on criteria for auxiliary heater activation

Note. On vehicles with A/C system, the switch-on requirements must be met in the Climatronic Control Module / or in A/C Control Module and in the respective ECM. On vehicles without A/C system (with heater only), the switch-on criteria must be met in the ECM and the Heater Control Module -J65- must connect through Ground (GND) as the switch-on signal, refer to TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C .

Climatronic Control Module / A/C Control Module sends a request to switch on the auxiliary heater to the Auxiliary Air Heater Control Module, to the ECM or the Auxiliary Heater Control Module (of parking heater) in the event the following requirements are met

1. Engine is running for a minimum of 8 seconds and engine speed is greater than 500 RPM.
2. Engine temperature is lower than 75 °C.
3. The calculated outside air temperature is lower than 8 °C.
4. The Stop function in the Start/Stop System is not active.
5. Vehicle voltage supply is greater than 12.2 volts and no request that forbids the switch-on is sent by Vehicle Electrical System Control Module -J519-.
6. No DTCs are stored in Climatronic Control Module / A/C Control Module.
7. No DTC is stored in ECM and output of Generator is less than 30 to 77% (depending on engine speed, this does not apply to activation of the parking heater as the auxiliary heater).
8. Based on the setting and the temperatures measured, Climatronic Control Module / A/C Control Module has calculated that additional heat output is necessary to attain the intended passenger compartment temperature.
9. More than 90% of air (position of temperature doors) is directed through heater core of heating A/C unit for the left or right side.

Note. On vehicles equipped with a auxiliary air heater control module it controls the auxiliary heater heating element in such way so the load on the generator does not exceed 95%. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". On vehicles with a 3-stage auxiliary heater heating element, the ECM actuates both relays for auxiliary heater in such a way that generator load does not exceed 95% Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" (for ECM) and refer to the appropriate SYSTEM WIRING DIAGRAMS information. Thus the next stage is switched on only in the event the generator load is less than 30 to 77%, depending on engine speed.

Switch-off criteria for auxiliary heater activation

Note. On vehicles with A/C system, activation is switched off as soon as one of the switch-on requirements in the Climatronic Control Module / or in A/C Control Module and in the respective ECM is no longer met or one of the switch-off criteria is detected.

Climatronic Control Module / A/C Control Module switches off the request to switch on the electric auxiliary heater.

1. When one of the switch-on requirements is no longer met.
2. The calculated outside air temperature is higher than 11 °C.
3. Generator load is greater than 95%.
4. Less than 60% of air is directed through heater core of heating A/C unit for the left and right sides (position of temperature doors).
5. The Stop function in the Start/Stop System is active.

Note. On vehicles equipped with a auxiliary air heater control module it controls the auxiliary heater heating element in such way so the load on the generator does not exceed 95%. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". On vehicles with a 3-stage auxiliary heater heating element, the ECM actuates both relays for auxiliary heater in such a way that the generator load does not exceed 95%. Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" => (for ECM) and refer to the appropriate SYSTEM WIRING DIAGRAMS information. If the load on the generator exceeds 95%, then the output of the auxiliary heater heating element will be reduced by one third.

COOLING PERFORMANCE - WITH AUTOMATICALLY REGULATED A/C SYSTEM, CHECKING

Special tools and workshop equipment required

1. Diagnostic operation system VAS 5051 A (or Vehicle Diagnosis and Service System VAS 5052).
2. Hose Clamps, Up to 40 mm. 3093
3. Standard thermometer (for temperature measurements, if necessary a thermometer with 2 measuring probes for simultaneous measurement e.g. for temperature at right and left)

Note. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. If the vehicles has a manual climate control system, then, depending on the setting on the A/C Control Module -J301- (for example, the heater is on) the Stop function will prevent the engine from being started again as soon as there is a request for heating. In the cooling mode the Stop function is not limited by the A/C control module. On vehicles with an automatic climate control system, the Climatronic Control Module -J255- prevents the Stop function, depending on the setting. If, for example, defrost is selected, the Stop Function is not possible or will be interrupted and the engine will start. The same applies in the case of heating and cooling. The difference between the selected and actual temperature is greater than a specified value shown using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

COOLING OUTPUT, CHECKING

Test requirements are met, refer to TEST REQUIREMENTS

Measure the ambient temperature (it must higher than 15 °C).

Close doors, hood, windows and sun roof.

Open all instrument panel vents.

Switch ignition on.

Start the engine.

Switch on Econ on the Climatronic control module (the indicator lap in the ECON button will come on; the indicator lamp in the AC button will not come on).

Initiate a Guided Fault Finding on the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051.

In read measured values block select the display group with the measured values for the compressor control and refrigerant circuit pressure and read the measured values using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

1. The A/C compressor is switched off, a current of 0 A (amps) will be displayed.
2. The pressure in the refrigerant circuit is same as the measured outside temperature or greater than the value in the chart.

Note. In terms of absolute pressure, 0 bar corresponds to an absolute vacuum. Normal ambient pressure equals approximately 1 bar absolute pressure. On the scales of most pressure gauges, 0 bar corresponds to an absolute pressure of one bar (can be seen from -1 mark below 0). Depending on version of Climatronic control module, only integer values may be displayed in the measuring value block, if the pressure measured lies between two values the display switches back and forth. Pressure in refrigerant circuit is governed by ambient temperature. On account of heat given off by components (e.g. radiator), pressure displayed with warm engine will be slightly higher than that given for the respective ambient temperature.

If the displayed pressure in the refrigerant circuit is lower than in the table

1. Check signal of High Pressure Sensor -G65-, refer to «HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL»(ref-496031-S06625037082012082100000) .
2. If no malfunction can be detected at High Pressure Sensor, there is insufficient refrigerant in the circuit, bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to «A/C PRESSURE/TEMPERATURE SENSOR -G395»(ref-496029-S25290663442012082100000) .

If pressure in refrigerant circuit is OK (the same or greater than specified in the table)

Switch on A/C compressor, select operating mode "Auto" on Climatronic control module to do so.

Set temperature preselect for driver and front passenger side to Lo on Climatronic control module.

Set direction of air flow to instrument panel vents at the Climatronic control module.

Read the required values in Guided Fault Finding using Vehicle Diagnosis, Testing and Information System VAS 5051.

Check the following values

1. The A/C compressor is on and a duty cycle greater than 30% is being displayed (the A/C Compressor Regulator Valve -N280- is working).
2. The A/C compressor is one and a current greater than 03 Amps is displayed (the current is flowing through the A/C compressor regulator valve).
3. The displayed pressure increases above the value when the compressor is switched off.

Note. If the displayed pressure does not change and the A/C compressor is working correctly, then make sure one more time that the A/C compressor is actually being driven. If the A/C compressor is being driven, there is a malfunction in the refrigerant circuit. Bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to REFRIGERANT CIRCUIT CONCERNS and refer to PRESSURES, CHECKING and refer to REMOVAL AND INSTALLATION . (it is possible that A/C compressor regulation is not OK). Bring the problems determined to the attention of the workshop. The A/C compressor regulator valve is controlled by the Climatronic control module so that the air temperature reaches the specified value (approximately 2 to 5 °C) after the evaporator: After starting the engine, and depending on the measured temperature, the engine RPM and voltage for controlling the A/C compressor regulator valve, a value greater than 75% (0.55 amps) is displayed. As soon as the temperature measured by Evaporator Vent Temperature Sensor -G263- nears the specified value, the activation, and thus the compressor output, is reduced. Under certain operating conditions, moisture in the refrigerant circuit can lead to ice build-up on the A/C compressor regulator valve (and on the expansion valve). A/C compressor control is reduced by this ice build-up, evaporator is cooled too intensely and freezes. The ice on the evaporator may cause various customer concerns, refer to ICE FORMATION ON EVAPORATOR, LOCALIZING MALFUNCTION . If no current or very little current is displayed in the A/C compressor regulator valve measured values block, then check the A/C compressor regulator valve, refer to A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL .

Press button for recirculating air mode on Climatronic control module (symbol for recirculating air mode lights up in button).

Set engine speed of 2000 rpm (start of time measurement).

In "read measured values block", select the display with the measured value from the evaporator vent temperature sensor. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Compare the displayed measured value (of the evaporator vent temperature sensor) to the values in the diagram using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Scheme 33

A - Measured air temperature of Evaporator Vent Temperature Sensor

B - Ambient temperature

C - Permissible tolerance range

Depending on the ambient temperature, the measured air temperature should be after 5 minutes within the shown tolerance range.

Note. If the required values are not reached, check the measured values on the evaporator vent temperature sensor, on the Left Vent Temperature Sensor -G150- and on the Right Vent Temperature Sensor -G151-, then compare the displayed measured values with each other: If the measured value deviates in the display fields, then perform the procedure for identifying malfunctions if specified values are not reached. Refer to DETERMINING MALFUNCTION IF SPECIFIED VALUES ARE NOT OBTAINED . If measured value of evaporator vent temperature sensor is greater than measured value of Left Vent Temperature Sensor and Right Vent Temperature Sensor, check evaporator vent temperature sensor for proper installation and perform an electrical test for this sensor, refer to Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function. The function of the air conditioning is recognizable, e.g. the refrigerant pipe on the low pressure side (thick line) cools off.

If the measured value for the evaporator vent temperature sensor (and therefore the system output) is OK

Compare the measured value for the evaporator vent temperature sensor with the measured values for the left vent temperature sensor and right vent temperature sensor.

The left vent temperature sensor and right vent temperature sensor measured values may not be greater than maximum 3 °C after 5 minutes, than the evaporator vent temperature sensor measured value.

Note. If the required values are not reached, then compare the displayed measured values from the left vent temperature sensor and the right vent temperature sensor to each other: If the measured value in one of the two sensors is OK, then check the activation and function of the left Temperature Door Motor -V158- and the Right Temperature Door Motor -V159-, refer to TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION , HEATING PERFORMANCE OF A/C SYSTEM, CHECKING and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the measured value from the left vent temperature sensor and from the right vent temperature sensor is lower then the value from the evaporator vent temperature sensor make sure the evaporator vent temperature sensor, left vent temperature sensor and right vent temperature sensor are installed correctly and check their electrical connectors for contact resistance. Replace the faulty sensor if necessary. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If there is no malfunction on the left vent temperature sensor and the right vent temperature sensor as well as on the left temperature door motor and the right temperature door motor, then determine the malfunction with temperature increase downstream of the evaporator. Refer to TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION . A commercially available thermometer can also be used to measure the air temperature coming out of the center instrument panel vents. If there are different air temperatures coming out of the vents, then this may be caused by the following: the temperature doors in the air distribution housing are not closing completely or they are not reaching their end position, refer to AIR GUIDE IN EVAPORATOR HOUSING and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding", there is air inside the heat exchanger (the air is not flowing evenly through the heat exchanger and therefore is not being warmed evenly, refer to) HEATING PERFORMANCE OF A/C SYSTEM, CHECKING or the foam seal came loose when installing the heat exchanger and the air is flowing over the heat exchanger.

DETERMINING MALFUNCTION IF SPECIFIED VALUES ARE NOT OBTAINED

Note. Only the Climatronic control module, part number 8P0 820 043 from index AE through index AH with software version 0430 (Audi A3 and Audi A3 Sportback) or from index BC or BD starting with software version 0800 (Audi A3 Cabrio) may be installed on vehicles with a 2.0L TFSI engine (engine code CAWB). If vehicle with this engine have a Climatronic control module with software version 0420 and 0700, then the control of the compressor is shut off by the Climatronic control module due to an unfounded request from the engine control module (the control current is limited to 300 mA, until the pressure in the refrigerant circuit exceeds approximately 7.5 bar) and the A/C cooling performance is unacceptable to the customer. Refer to CLIMATRONIC CONTROL MODULE .

TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION

ICE FORMATION ON EVAPORATOR, LOCALIZING MALFUNCTION

1. The A/C Compressor Regulator Valve -N280- is controlled by the Climatronic control module or by theA/C control module so that the air temperature after the evaporator reaches the specified value (approximately 2 to 5 °C).
2. After starting the engine, and depending on the measured temperature, the engine RPM and the voltage for the Climatronic control module or A/C control module and for the A/C compressor regulator valve is greater than 75% (0.55 A) using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". As soon as the temperature measured by evaporator vent temperature sensor nears the specified value, the activation, and thus the compressor output, is reduced.
3. Under certain operating conditions, moisture in the refrigerant circuit can lead to ice build-up on the A/C compressor regulator valve (and on the expansion 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.

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.

Vehicles with automatically regulated A/C system: after a long drive, windows fog up from inside, windows are also not cleared by then pressing the Defrost button, after switching off vehicle and after a short time, A/C function is OK again.

Corrective action

Check the measured value from the evaporator vent temperature sensor. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

If the sensor measured is too high under the operating conditions reported by the customer (even though the A/C system is operating without difficulty at greater than e.g. 10 °C, depending on ambient temperature), check the evaporator vent temperature sensor (an incorrect measured value may cause evaporator the ice up).

Is the measured value from the sensor is below the operating condition described by the customer (at an temperature above 0 °C, longer when it is lower than 0 °C). Bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to CHECKING PRESSURE WITH SERVICE STATION . Bring the problems determined to the attention of the workshop.

Check refrigerant line from evaporator (from expansion valve) to A/C compressor (thick tube, low pressure side) with engine running. If this line is thickly iced-up when a problem occurs (a very thin layer of ice is permitted), this indicates that the temperature in the evaporator is too low. Bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to PRESSURES, CHECKING . If the A/C compressor control is not OK, then inform the workshop of the problem at hand.

COOLING PERFORMANCE - WITH MANUALLY REGULATED A/C SYSTEM, CHECKING

Special tools and workshop equipment required

1. Diagnostic operation system VAS 5051 A (or Vehicle Diagnosis and Service System VAS 5052).
2. Hose Clamps, Up to 40 mm. 3093
3. Standard thermometer (for temperature measurements, if necessary a thermometer with 2 measuring probes for simultaneous measurement e.g. for temperature at right and left)

Note. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. If the vehicles has a manual climate control system, then, depending on the setting on the A/C Control Module -J301- (for example, the heater is on) the Stop function will prevent the engine from being started again as soon as there is a request for heating. In the cooling mode the Stop function is not limited by the A/C control module. On vehicles with an automatic climate control system, the Climatronic Control Module -J255- prevents the Stop function, depending on the setting. If, for example, defrost is selected, the Stop Function is not possible or will be interrupted and the engine will start. The same applies in the case of heating and cooling. The difference between the selected and actual temperature is greater than a specified value shown using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Test requirements are met, refer to TEST REQUIREMENTS .

Measure the ambient temperature (it must higher than 15 °C).

Close doors, hood, windows and sun roof.

Open all instrument panel vents.

Switch ignition on.

Switch off the A/C compressor via the AC -button (indicator lamp in AC -button does not light up).

Start the engine.

Initiate a Guided Fault Finding on the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Select Guided Fault Finding and read the following values (A/C Compressor Regulator Valve -N280- control and the High Pressure Sensor -G65-) measured value using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

1. The A/C compressor activation is switched off.
2. The pressure in the refrigerant circuit is same as the measured outside temperature or greater than the value in the chart.

Note. In terms of absolute pressure, 0 bar corresponds to an absolute vacuum. Normal ambient pressure equals approximately 1 bar absolute pressure. On the scales of most pressure gauges, 0 bar corresponds to an absolute pressure of one bar (can be seen from -1 mark below 0). Pressure in refrigerant circuit is governed by ambient temperature. On account of heat given off by components (e.g. radiator), pressure displayed with warm engine will be slightly higher than that given for the respective ambient temperature. Only integer values are displayed for the pressure in refrigerant circuit in the measuring value block of A/C control module, if the value measured lies between two values the display switches back and forth.

If the displayed pressure in the refrigerant circuit is lower than in the table

1. Check the high pressure sensor signal, refer to «HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL»(ref-496031-S06625037082012082100000) .
2. If no malfunction can be detected at high pressure sensor, there is insufficient refrigerant in the circuit, bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to «PRESSURES, CHECKING»(ref-496030-S17004451432012082100000) .

If pressure in refrigerant circuit is OK (the same or greater than specified in the table)

Switch on the A/C compressor, to do so press the AC -button on A/C control module (indicator lamp in AC comes on)

Set the lowest possible temperature (turn the temperature rotary switch all the way to cold).

Set the air flow direction to instrument panel vents via the air distribution rotary switch.

Set speed 4 on fresh air blower rotary switch.

Switch A/C system to recirculating air mode by pressing recirculating air mode button on (indicator lamp in recirculating air button comes on).

Select "Guided Fault Finding" and read the following values using Vehicle Diagnosis, Testing and Information System VAS 5051.

1. The A/C control module calculate the current that is flowing via the A/C Compressor Regulator Valve and is greater than 0.3 Amps (the A/C compressor is on).
2. The displayed pressure increases above the value when the compressor is switched off.

Note. If the displayed pressure does not change and the A/C compressor control is OK, then check the calculated pressure one more time via the A/C Compressor regulator valve and make sure the A/C compressor is actually being driven by the /C Compressor regulator valve, then there is malfunction in the refrigerant circuit. Bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel, refer to PRESSURES, CHECKING (it is possible that A/C compressor regulation is not OK). Bring the problems determined to the attention of the workshop. The A/C Compressor Regulator Valve is controlled by the A/C control module so that the air temperature after the evaporator reaches the specified value (approximately 2 to 5 °C). After starting the engine, and depending on the measured temperature, the engine RPM and the voltage for the A/C Compressor regulator valve, a value greater than 055 Amps is displayed. As soon as the temperature measured by evaporator vent temperature sensor nears the specified value, the activation, and thus the compressor output, is reduced. Under certain operating conditions, moisture in the refrigerant circuit can lead to ice build-up on the A/C compressor regulator valve (and on the expansion valve). A/C compressor control is reduced by this ice build-up, evaporator is cooled too intensely and freezes. The ice on the evaporator may cause various customer concerns, refer to ICE FORMATION ON EVAPORATOR, LOCALIZING MALFUNCTION . If the A/C compressor regulator valve measured blocks value, or if no current or very little current is displayed, check the A/C compressor regulator valve control A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL .

Press button for recirculating air mode on A/C control module (indicator lamp for recirculating air mode in button lights up).

Set engine speed of 2000 rpm (start of time measurement).

Select "read measured values block" using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Compare the displayed measured value evaporator vent temperature sensor) to the values in the diagram.

A - Measured air temperature of evaporator vent temperature sensor

B - Ambient temperature

C - Permissible tolerance range

Depending on the ambient temperature, the measured air temperature should be after 5 minutes within the shown tolerance range.

Note. If the required values have not been reached, measure temperature of the air flowing out of instrument panel vents using a thermometer. Compare this value with the displayed measured value of evaporator vent temperature sensor. If both measure values deviate only slightly from one another, perform malfunction identification when specified value is not reached, refer to DETERMINING MALFUNCTION IF SPECIFIED VALUES ARE NOT OBTAINED . If the measured value from the evaporator vent temperature sensor is larger than your measured value, then make sure the evaporator vent temperature sensor is installed correctly and perform an electrical test on the sensor. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". The function of the air conditioning is recognizable, e.g. the refrigerant pipe on the low pressure side (thick line) cools off.

If the measured value for the evaporator vent temperature sensor (and therefore the system output) is OK

Measure temperature of the air flowing out of left and right instrument panel vents using a thermometer.

Compare your measured values (Left Vent Temperature Sensor -G150-, Right Vent Temperature Sensor -G151- and evaporator vent temperature sensor). The measured values may not be smaller and after 5 minutes be greater than maximum 3 °C, than the value of the evaporator vent temperature sensor.

Note. If the measured value are smaller, make sure the evaporator vent temperature sensor is installed correctly and check the electrical connections for contact resistance; replace the sensor if it is defective. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If the required values are not reached on one or both sides, then check the temperature door control and function. Perform a malfunction search if the temperature rises, refer to TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION and Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding". Problems relating to differences between temperature of air emitted by left and right vents with identical setting in air conditioner regulated mode may have the following causes: One of the temperature doors in air distribution housing does not close completely or does not reach its end position AIR GUIDE IN EVAPORATOR HOUSING and Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. There is air in the heater cores (fluctuating flow through heater core and heat is not distributed uniformly) HEATING PERFORMANCE OF A/C SYSTEM, CHECKING or a foam seal was loosened during installation of the heater core and air may bypass the heater core.

Note. Vehicles with manually regulated A/C system: temperature doors for left and right side are connected to each other via the shaft.

HEATING PERFORMANCE OF A/C SYSTEM, CHECKING

Special tools and workshop equipment required

1. Diagnostic operation system VAS 5051 A (or Vehicle Diagnosis and Service SystemVAS 5052).

Note. If coolant circuit is not completely bled after filling, air may accumulate in heater core of A/C unit, thus reducing heating performance of A/C system, additional noises may occur or customer may complain of different air temperatures flowing out of vents at driver side and front passenger side at the same setting. For this malfunction, perform a long road test at increased engine speed (at least 10 minutes, engine speed greater than 2500 RPM). Select a low gear during the test to prevent excessive vehicle speed. If customer complains of poor heating performance at specific engine speeds, check incorporation of heater core in A/C system in the coolant circuit. If both coolant hoses (supply and return) of engine are interchanged, coolant is flowing in the wrong direction through the heater core. Refer to HEATING PERFORMANCE, CHECKING . In vehicles with a parking heater, check activation of Recirculation Pump -V55-, of parking heater as well as incorporation of parking heater in coolant circuit. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. If the vehicles has a manual climate control system, then, depending on the setting on the A/C Control Module -J301- (for example, the heater is on) the Stop function will prevent the engine from being started again as soon as there is a request for heating. In the cooling mode the Stop function is not limited by the A/C control module. On vehicles with an automatic climate control system, Climatronic Control Module -J255- prevents the Stop function, depending on the setting. If, for example, defrost is selected, the Stop Function is not possible or will be interrupted and the engine will start. The same applies in the case of heating and cooling. The difference between the selected and actual temperature is greater than a specified value shown using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the vehicle has the Start/Stop System, there is no additional coolant pump. An electric coolant pump may be present depending on the vehicle engine, which is controlled by an engine control module. Refer to GENERAL INFORMATION and refer to COOLANT PUMP AND COOLANT THERMOSTAT ASSEMBLY OVERVIEW and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Climatronic control module, part number 8P0 820 043 starting with index BM sends the request to control the electric coolant pump only with the correct adaptation on the databus. Make sure a Climatronic control module with the index BM is installed using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

HEATING PERFORMANCE - WITH AUTOMATICALLY REGULATED A/C SYSTEM, CHECKING

Test Requirements

1. Coolant circuit has been bled according to specifications, refer to «COOLING SYSTEM, DRAINING AND FILLING»(ref-496050-S08883835322012082100000) .
2. All air guides, covers and seal OK and properly installed.
3. Air flow through dust and pollen filter not obstructed by dirt.
4. Engine is warm
5. The Climatronic control module was checked and erased and the basic setting was performed using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
6. The Climatronic control module coding has been checked using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
7. The Climatronic control module adaptation has been checked using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
8. Vehicle not exposed to sunlight

Heating Performance, Checking

Close hood.

Close doors, windows and sun roof.

Initiate a Guided Fault Finding on the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Open all dash panel vents.

Read the measured values for the Left Vent Temperature Sensor -G150- and Right Vent Temperature Sensor -G151- using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Check and compare the displayed measured values.

1. Specified temperature: maximum 12 °C, depending on the outside temperature, variance between the measured values: less than 3 °C.

Set air distribution to instrument panel vents.

Set temperature preselect for left side (driver side) on Climatronic control module to Hi.

Read the left vent temperature sensor and right vent temperature sensor displayed measured values.

Specified Values

1. In the display field with the measured value for the left vent temperature sensor the temperature goes above 55 °C when the engine temperature is approximately 90 °C. In the display field with the measured value for the right vent temperature sensor the temperature goes up less than 10 °C.

Set temperature preselect for right side (front passenger side) on Climatronic control module to Hi.

Read the displayed measured values for the left vent temperature sensor and right vent temperature sensor.

Specified Values

1. In the display field with the measured value for the left vent temperature sensor, the temperature increases to approximately the engine temperature; the difference between the display fields for the measured fields of the left vent temperature sensor and the right vent temperature sensor is less than 8 °C.

Set temperature preselect for driver side on Climatronic control module to LO.

Read the displayed measured values for the left vent temperature sensor and right vent temperature sensor.

Specified Values

1. Temperature for left side (driver side) decreases within 5 minutes to less than 12 °C depending on ambient temperature.

If necessary, perform this test step for front passenger side in the same way.

If the specified values are not reached, check the following

Ventilation of coolant circuit, refer to DESCRIPTION AND OPERATION and refer to DIAGNOSIS AND TESTING .

Incorporation of heater core for heater in A/C unit into coolant circuit, refer to DISASSEMBLY AND ASSEMBLY and refer to HEATER UNIT .

Activation and function of Left Temperature Door Motor -V158- and of Right Temperature Door Motor -V159- using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Foam seal on heater core for heater of A/C unit, refer to HEAT EXCHANGER .

Function of temperature doors in air distribution housing, refer to AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT .

Coolant regulator (engine coolant may not warm properly if regulator is malfunctioning), refer to THERMOSTAT, CHECKING .

HEATING PERFORMANCE - WITH MANUALLY REGULATED A/C SYSTEM, CHECKING

Test Requirements

1. Coolant circuit has been bled according to specifications, refer to «COOLING SYSTEM, DRAINING AND FILLING»(ref-496050-S08883835322012082100000) .
2. All air guides, covers and seal OK and properly installed.
3. Air flow through dust and pollen filter not obstructed by dirt.
4. Engine is warm
5. The A/C Control Module -J301- was checked and erased, and a basic setting was performed using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function."
6. Vehicle not exposed to sunlight

Heating Performance, Checking

Close hood.

Close doors, windows and sun roof.

Initiate a Guided Fault Finding on the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Open all dash panel vents.

Start the engine and let it run for a few minutes with maximum cooling output. The A/C compressor is switched on, the indicator lamp in the AC button comes on and the temperature rotary switch is turned all the way to cold.

Set the air flow direction to instrument panel vents via the air distribution rotary switch.

Set speed 4 on fresh air blower rotary switch.

Measure temperature of the air flowing out of left and right instrument panel vents using a thermometer.

Compare the measured values with the displayed measured value from the Evaporator Vent Temperature Sensor -G263-. The measured values may not be smaller and after 5 minutes be greater than maximum 3 °C, than the value of the evaporator vent temperature sensor.

Specified Values

1. Temperature maximum 12 °C, depending on ambient temperature, the difference between the measured values is less than 3 °C.

Set the highest possible temperature (temperature rotary switch turned all the way to warm).

Measure temperature of the air flowing out of left and right instrument panel vents using a thermometer.

Specified Values

1. Temperature increases to greater than 55 °C at an engine temperature of approximately 90 °C, deviation between the left and right side is less than 8 °C.

Set the lowest possible temperature (turn the temperature rotary switch all the way to cold).

Measure temperature of the air flowing out of left and right instrument panel vents using a thermometer.

Specified Values

1. Temperature decreases within 5 minutes to less than 12 °C depending on ambient temperature.

If the specified values are not reached, check the following

Ventilation of coolant circuit, refer to DESCRIPTION AND OPERATION and refer to DIAGNOSIS AND TESTING .

Incorporation of heater core for heater in A/C unit into coolant circuit.

Activation and function of Temperature Regulator Door Motor -V68-. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Foam seal on heater core for heater of A/C unit, refer to HEAT EXCHANGER .

Function of temperature doors in air distribution housing, refer to AIR GUIDE IN AIR DISTRIBUTION HOUSING .

Coolant regulator (engine coolant may not warm properly if regulator is malfunctioning), refer to THERMOSTAT, CHECKING .

HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL

Special tools and workshop equipment required

1. Connector Test Set V.A.G 1594/C
2. Vehicle Diagnostic, Testing and Information System VAS 5051 A

Note. Vehicles with automatically regulated A/C system: Climatronic Control Module -J255- evaluates the signal from High Pressure Sensor -G65- and actuates the compressor via the A/C Compressor Regulator Valve -N280-. Vehicles with manually regulated A/C system: A/C Control Module -J301- evaluates the signal from high pressure sensor and actuates the compressor via the A/C compressor regulator valve. The cooling output cannot be checked when the high pressure sensor is removed; the Climatronic control module / the A/C control module does not switch on the compressor using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Depending on the version of the high pressure sensor, an insufficient measuring value for the pressure in the refrigerant system will be sent by the high pressure sensor at low outside temperatures (lower than 5 °C) (even though the A/C system is OK and the refrigerant circuit is properly filled). In the A/C control module or in the Climatronic control module, part number 8P0 820 043 up to index AH can register an incorrect DTC memory entry at low outside temperatures (lower than 5 °C) (DTC memory entry: high pressure sensor lower values not met). If the fault is displayed as a sporadic fault at an outside temperature greater than 5 °C, calculated by the A/C system, and if the A/C function is OK, then clear the DTC memory (no additional steps are necessary). Different component locations depending on engine, high pressure sensor in vehicles with 2.0L Diesel engine is installed not on refrigerant line from expansion valve to condenser but rather on refrigerant line from compressor to condenser. Currently on 4-cylinder vehicles, it is possible to disconnect the high pressure sensor connector without have to remove any other components because the connector is accessible from above. After switching off the A/C compressor on this vehicle, it may take a long time until the pressure on the high pressure side (the expansion valve is cold and the pressure on the low pressure side increases quickly after switching off, the expansion valve closes and the refrigerant can flow slowly on the low pressure side.

Remove the noise insulation (for example, on 6-cylinder vehicles). Refer to Removal and Installation .

Disconnect the connector -A-.

Scheme 34

Connector Assignment High Pressure Sensor

Terminal -1- ground

Terminal -2- signal output (square-wave signal to the Climatronic control module / to the A/C control module)

Terminal -3 - positive (terminal 75)

Note. When connector -A- is disconnected, the A/C compressor will not switch on. The high pressure sensor -B- is an electronic control module, which creates a square wave signal, the duty cycle ratio changes with pressure in the refrigerant circuit.

The Pressure Signal From The High Pressure Sensor

A- Pressure on the high pressure side in the refrigerant circuit in bar (absolute pressure)

Scheme 35

B- square-wave signal duty cycle

C- square-wave signal duty cycle characteristic line

Note. The Climatronic control module / the A/C control module switches the compressor on, as long as there are no compressor shut-off conditions (by controlling the A/C compressor regulator valve). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Depending on the version of the high pressure sensor, an insufficient measuring value for the pressure in the refrigerant system will be sent by the high pressure sensor at low outside temperatures (lower than 5 °C) (even though the A/C system is OK and the refrigerant circuit is properly filled). In the A/C control module or in the Climatronic control module, part number 8P0 820 043 up to index AH can register in incorrect DTC memory entry at low outside temperatures (lower than 5 °C) (DTC memory entry: high pressure sensor lower values not met). If the fault is displayed as a sporadic fault at an outside temperature greater than 5 °C, calculated by the A/C system, and if the A/C function is OK, then clear the DTC memory (no additional steps are necessary). If duty cycle is greater than 12% (corresponding to approximately 1.2 bar absolute) and less than 78% (corresponding to approximately 32 bar absolute) The compressor is not switched on if the duty cycle is smaller than 12% or greater than 78% (A/C compressor regulator valve is not activated). The duty cycle and the pressure calculated by the Climatronic control module / the A/C control module is displayed in the measured value block using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". In terms of absolute pressure, 0 bar corresponds to an absolute vacuum. Normal ambient pressure equals approximately 1 bar absolute pressure. 0 bar pressure corresponds to an absolute pressure of approximately 1 bar on most pressure gauges (indicated by -1 below 0). The Climatronic control module / the A/C control module sends the request to increase the Coolant Fan -V7- RPM to the engine control module via the Data bus regardless of the calculated refrigerant circuit pressure and when the A/C compressor is on. Depending on version with a certain pressure in the refrigerant circuit or not depending on pressure as long as soon as the A/C compressor is switched on. Request determined by Climatronic control module / A/C control module is displayed in measuring value block (Read measured values block) using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". The request for the coolant fan is currently sent at the following duty cycle: Pressure in refrigerant circuit less than approximately 9 bar (6 bar when pressure was greater than 9 bar), no request Pressure in refrigerant circuit greater than approximately 9 bar (6 bar) up to approximately 20 bar, request of 30 to 100 % (depending on pressure) If the refrigerant circuit pressure is greater than 20 bar, a 100% request will be made. The signal generated from v is also used to control the engine. Climatronic control module / A/C control module sends the information to the ECM via the CAN-Bus Comfort system (the necessary torque to drive the A/C control module depends on the pressure in the refrigerant circuit). Depending on version of ECM, the signal in the measured value block is displayed as the duty cycle using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function (for respective ECM installed).

This pattern appears on oscilloscope screen (for example on VAS 5051 A) when the following conditions are met.

Scheme 36

Ignition switched on (B+ at terminal 3 and Ground (GND) terminal 1 on high pressure sensor present)

Oscilloscope setting: 5V / Div. = (5V per unit DC voltage) 5 ms / Div. (5 milliseconds per unit)

Measuring lead (signal wire) connected to terminal 2 on high pressure sensor.

Measuring lead (shielding) connected to terminal 1 (Ground -GND- on high pressure sensor).

Note. The illustration shows the signal, which is sent when the refrigerant circuit pressure is approximately 7 bar. This conforms to a approximate 25% duty cycle. With compressor not engaged, an ambient temperature of 30 °C and properly filled refrigerant circuit. The impulse width -A- depends on the pressure in the refrigerant circuit (if pressure increases, area -A- gets wider). The signal distance -B- is always 20 milliseconds. This corresponds to frequency of 50 Hertz. The duty cycle is determined by the ratio of impulse width -A- and signal distance -B-. Use the measuring leads from the V.A.G 1594/C or an adapter lead for this test. To do this, e.g. use connectors -A- and -B- (part number 1J0 973 703 and 1J0 973 803 and relevant terminal contacts), two standard sockets for banana connectors -C- and three wires with 0.5 mm 2 diameter.

PARKING HEATER, POOR OUTPUT

If a customer complains of poor heating performance, check heat output of A/C system, refer to HEATING PERFORMANCE OF A/C SYSTEM, CHECKING .

In vehicles with a parking heater installed as optional equipment, if there is a complaint of poor or insufficient heating performance at low engine speeds, check activation of Heater Coolant Shut-Off Valve -N279- and of Recirculation Pump -V55- of parking heater by Auxiliary Heater Control Module -J364-.

1. Heater coolant shut-off valve is activated when parking heater is switched off and ignition is switched on. If shut-off valve is activated, coolant does not flow directly from heater core to engine (rather via the parking heater). With parking heater switched on, heater coolant shut-off valve is only then actuated with ignition switched on e.g. when coolant temperature in parking heater is greater than the coolant temperature in the engine.
2. By activating recirculation pump, coolant flow through A/C system heater core is increased at lower engine speeds and thus better heating performance is achieved.
3. The auxiliary heater control module switches on the recirculation rump when the following information is received via the data bus

Ignition on and engine running

Outside air temperature lower than 20 °C

Engine speed less than 2, 000 rpm

Vehicles with automatically regulated A/C system: Climatronic Control Module -J255- is switched on and heating output is requested for at least one side (driver or front passenger side).

Using the A/C (A/C Control Module -J301-) requires heating, the temperature rotary switch is turned to warm (on vehicles with a manual climate control system). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

1. The recirculation pump is switched on as soon as all the requirements are met. To stop circulation pump being constantly switched off and on, it remains activated for at least 30 seconds even if - for example in the event of rapid changes in vehicle speed - a request is only applied for several seconds (e.g. on accelerating after standing at traffic lights).
2. Incorporation of parking heater (and of recirculation pump) in coolant circuit.

REAR WINDOW DEFOGGER WITH MANUALLY REGULATED A/C SYSTEM, CHECKING

A/C Control Module -J301- activation

1. By pressing the button -E- with the ignition switched on, the Vehicle Electrical System Control Module -J519- is activated (by the A/C control module via the data bus). As soon as the vehicle electrical system control module switches on the rear window defroster (only when the engine is running), the indicator lamp in the button -E- comes on (the vehicle electrical system control module sends the request via the data bus). Rear window heater is switched off by pressing button -E- again and by switching ignition off. Refer to refer to the appropriate SYSTEM WIRING DIAGRAMS information.
2. If the voltage measured on the vehicle electrical system control module to terminal 30 is below the valued stored in the vehicle electrical system control module, then the activation of the Rear Window Defogger -Z1- will be switched off completely and this will relieve the load on the generator. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
3. The rear window defogger is controlled by the vehicle electrical system control module only when the engine is running. If the engine is not running, there is no control and there is no request from the vehicle electrical system control module. The LED in the button -E- does not come on, or will go out shortly after the button is pressed. Refer to Owner's manual and refer to the appropriate SYSTEM WIRING DIAGRAMS information.
4. If rear window defogger must be switched off for a short time by vehicle electrical system control module due to insufficient voltage, indicator lamp in heated rear window button -E- remains switched on, if switch-off is prolonged however, vehicle electrical system control module switches off the indicator lamp.
5. Function test of heated rear window activation is described in Guided Fault Finding for vehicle electrical system control module and for A/C system. Use Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
6. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with the Start/Stop System, the rear window defogging is switched off whenever the Stop function is active (to protect the battery). The setting for the rear window defogger remains stored. After the engine is started again by the Start function, rear window defogging is switched on again. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Note. The function and the control of the rear window defogger is displayed in the measured values block of the A/C control module using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". The rear window defogger switches itself off when the outside air temperature is higher than 0 °C and after about 10 minutes by the vehicle electrical system control module. The heated rear window stays switched on with outside temperatures up to 0 °C until ignition is switched off (heated rear window can be switched off and back on manually at anytime). If the temperature increases above 0 °C during a driving cycle, the heated rear window will be switched off after the specified operating time stored in vehicle electrical system control module (approximately 10 minutes) has elapsed.

REAR WINDOW DEFOGGER WITH AUTOMATICALLY REGULATED A/C SYSTEM, CHECKING

Climatronic Control Module -J255- activation

Note. If condition is present, so that the rear window heating does not turn on, for example, if there is a short circuit in the connection to the rear window or there is a interruption in the voltage supply to the Climatronic control module, then this will be stored in the control module as a malfunction. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If the voltage on the Vehicle Electrical System Control Module -J519- to terminal 30 falls below the valued stored, the rear window defroster will be switched off completely or the power reduced to relieve the load on the generator. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. The rear window defogger is controlled by the vehicle electrical system control module only when the engine is running. If the engine is not running, there is no message from the vehicle electrical system control module and the LED in the button in the Climatronic control module will go out for the short period. If heated rear window must be switched off due to insufficient voltage, indicator lamp in heated rear window button on Climatronic control module remains switched on, however if switch-off is to last longer than approximately 150 seconds, Climatronic control module switches off the indicator lamp. Measuring value block of Climatronic control module indicates that Rear Window Defogger -Z1- activation is switched on or why no activation is occurring despite a request. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Checking actuation of rear window defogger operation is described in Guided Fault Finding for A/C system for air conditioner using Vehicle Diagnosis, Testing and Information System VAS 5051. With outside temperatures greater than 0 °C the rear window defogger is switched off automatically by Climatronic control module after the programmed operating time (approximately 10 minutes) has elapsed. With ambient temperatures less than 0 °C in vehicles which were built from beginning of production, rear window defogger is switched off by vehicle electrical system control module after approximately 20 minutes. At a later point in time, vehicle electrical system control modules are installed (running change in production) in which rear window defogger activation remains switched on until ignition is switched off (it can be switched off and back on again manually at any time). If the temperature becomes greater than 0 °C during a driving period, switch-off of the rear window defogger occurs after the operating time stored in the Climatronic control module has elapsed (approximately 10 minutes). From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with the Start/Stop System, the rear window defogger is switched off whenever the Stop function is active (to protect the battery). The setting for the rear window defogger remains stored in the Climatronic control module. After the engine is started again by the Start function, rear window defogger is switched on again. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

SEAT HEATER ACTIVATION

Note. From MY 2009, as a running change, the Climatronic Control Module -J255- (or control modules for seat heating) is being installed, whereby the specified temperature is set to a lower characteristic line. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

WITH AUTOMATICALLY REGULATED A/C SYSTEM

Climatronic Control Module -J255- activation

Note. If there is a condition that prevents the driver or passenger seat heating from switching on such as a short circuit in the connection to the seat heating element or an open circuit in the voltage supply to the Climatronic Control Module -J255-, this will be stored as a fault in the Climatronic control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function. The function test for the heated seat activation is described in A/C system Guided Fault Finding using vehicle diagnosis, testing and information system VAS 5051. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. On vehicles with the Start/Stop System, seat heating and ventilation is switched off whenever the Stop function is active (by the Vehicle Electrical System Control Module -J519- to protect the battery). After the engine is started again by the Start function, seat heating and ventilation is switched on again. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". If the voltage measured on terminal 30 falls below the value stored in the vehicle electrical system control module, then the heat seating power will be switched off completely to take the load off the generator. The Climatronic control module electronics reduces the duty cycle from 100% to less than 90 to 0.0%. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Climatronic control module measured value block indicates the front seat heater is switched on or why no activation is occurring despite a request. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

WITH MANUALLY REGULATED A/C SYSTEM

A/C Control Module -J301- activation

Note. On vehicles with manual climate control system, activation of heated seats is not monitored by the A/C Control Module -J301- electronics, therefore malfunctions are not stored in DTC memory.

1. The A/C control module provides a voltage via the Heated Driver Seat Adjuster -E94- and Heated Front Passenger Seat Adjuster -E95- (a potentiometer is operated via the respective knurled wheel -C-).
2. The voltage supplied by A/C control module -A- with seat heater switched on is dependent on the knurled wheel position and on the vehicle voltage supply, it is in the range of less than 0.5 volts in position 0 to approximately 10 volts in position 5 (measured to Ground -GND- e.g. at connector -B- terminal 20) with engine running. The voltage is transferred via connector -B- (from terminal 13 to Driver Seat Heater Control Module -J726- and from terminal 12 to Front Passenger Seat Heater Control Module -J727-), refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Note. Resistance of seat heater potentiometer is dependent on the knurled wheel position, it cannot be measured using workshop equipment.

1. Check function of seat heater and service it. Refer to «Removal and Installation»(ref-496130-S14637100472012082100000) and refer to the appropriate SYSTEM WIRING DIAGRAMS information.

VENT FRAME, CHECKING

Note. On the Audi A3 Cabrio, the ventilation openings -B- in the rear lid trim -A- must not be covered by any objects when the rear lid is closed. The following 3 illustrations show the layout and the version of the components of the extraction outlets on the Audi A3; the layout and the components on the Audi A3 Sportback and on the Audi A3 Cabrio have some slight differences (the function however is the same).

Check ventilation channels to both ventilation frames -A- in luggage compartment (left and right) for throughput.

Scheme 37

1. Sealing lips -B- in ventilation frames -A- must move freely and close by themselves.
2. Blocked channels to ventilation frames or jammed sealing lips may cause windows to fog up.

Note. In this illustration, ventilation frame -A- is depicted with rear bumper removed. For forced air extraction, one ventilation frame -A- each is installed on left and right. So that sealing lips -B- close correctly, ventilation frame -A- must be installed on proper side (smaller radius -C- at top). In order for the passenger compartment ventilation to function properly, the vent openings -A- and -B- in the luggage compartment trim on left and right must not be closed.

A/C COMPRESSOR

Note. Depending on time period of production and on engine, compressor construction type may vary. At the start of production, Denso (type 7 SEU 16 or 7 SEU 17) A/C compressors were installed; beginning with MY 2004 A/C compressors made by other manufacturers (Delphi, Sanden or Zexel Valeo) were installed, Refer to Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on A/C compressor and the exact part number. Refer to REFRIGERANT R134A CAPACITIES . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. Depending on A/C compressor type, different refrigerant oil fill capacities are designated for the refrigerant circuit. The reason for the different oil capacities in the A/C compressor for an otherwise identical refrigerant circuit lies in the design of the A/C compressor itself, note these oil capacities. Too much oil in the circuit leads to high pressures and to a reduction in the system cooling performance, too little oil may lead to lubrication problems in the A/C compressor, refer to REFRIGERANT R134A CAPACITIES . If a new compressor has been installed or new refrigerant oil has been put into the A/C compressor (e.g. after blowing through the A/C system), the A/C compressor must be turned by hand approximately 10 revolutions. This ensures that the compressor is not damaged when activated.

Removing

Evacuate the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT .

Disconnect refrigerant lines from A/C compressor, refer to REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR .

Remove A/C compressor from bracket. Refer to COMPRESSOR, REMOVING FROM BRACKET .

Installing

Installation is carried out in the reverse order, when doing this note the following

Before installing the A/C compressor, refer to Removal and Installation .

Note. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . An uncertain quantity of refrigerant oil remains in a removed A/C compressor, therefore observe notes for replacing the A/C compressor. Refer to COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT .

1. Tightening specifications, refer to «COMPRESSOR, REMOVING FROM BRACKET»(ref-496031-S01673880982012082100000) and «REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR»(ref-496031-S02917555142012082100000) .
2. Replace the O-rings at the opened connection locations. Refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) .

Only start engine after refrigerant circuit has been assembled.

If a new A/C compressor has been installed or fresh refrigerant oil has been filled into the A/C compressor before installing ribbed belt (for example, after cleaning refrigerant circuit), the A/C compressor must be turned by hand approximately 10 turns. This ensures that the A/C compressor will not be damaged when engine is first started.

If possible start engine only with a filled refrigerant circuit.

Note. Different A/C compressors, depending on production time period and on engine, refer to REFRIGERANT CIRCUIT, SERVICING . The A/C compressor is always driven by a belt pulley (there is no magnetic clutch). The compressor has an internal oil circuit to ensure the A/C compressor is not damaged when refrigerant circuit is empty. Prerequisite for the internal lubrication is residual refrigerant oil in A/C compressor. The engine may only be started when the refrigerant circuit is installed correctly. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine. As there is no refrigerant in the circuit the oil required to lubricate is not fed to the A/C compressor. To prevent damage, the A/C compressor is lubricated by an internal oil circuit.

1. If it is necessary to start the engine with a discharged refrigerant circuit. Refer to «A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT»(ref-496031-S30292694612012082100000) .

COMPRESSOR, REMOVING FROM BRACKET

Note. The A/C compressor can be removed and installed at the bracket without opening the refrigerant lines. In the following, removal and installation of A/C compressor is described for a vehicle with a 2.0 L gasoline engine with a Denso A/C compressor, type 7 SEU 16. On vehicles with different engine or a different A/C compressor, slight changes may result (depending on engine, additional assemblies may need to be removed or loosened) Do not discharge the refrigerant circuit, do not remove refrigerant hoses and lines from the A/C compressor. Do not unfasten refrigerant pipes and corresponding clamps. After removing, tie the A/C compressor to the longitudinal member with wire. Never leave hanging from refrigerant pipes. Before removing, mark direction of operation of ribbed belt with chalk or felt-tipped pen. Reversing the direction of rotation of a run-in belt can destroy the belt. Refer to [For engine(s) CBRA] RIBBED BELT or refer to [For engine(s) BPY] RIBBED BELT or refer to [For engine(s) CCTA, CBFA] RIBBED BELT or refer to [For engine(s) CBEA] Removal and Installation . Different compressors may be installed depending on the engine and country.

Removing the A/C Compressor From the Bracket

Remove the engine cover (depending on engine, not necessary for all engine types). Refer to ENGINE COVER WITH AIR FILTER ELEMENT .

Remove center noise insulation. Refer to Removal and Installation .

Scheme 38

Remove the noise insulation frame, if equipped (for example, currently on the Audi A3 Cabrio). Refer to Removal and Installation .

Mark running direction of ribbed belt (illustration shows arrangement for a 4 cylinder engine).

Scheme 39

Release the tension on the ribbed belt and then remove it. Refer to [For engine(s) CCTA, CBFA] Removal and Installation , or refer to Removal and Installation .

Note. The illustration shows a ribbed belt on a 2.0L FSI engine. The allocation can vary on other 4-cylinder engines. Refer to [For engine(s) CBRA] Removal and Installation , or refer to [For engine(s) BPY] Removal and Installation .

Disconnect electrical connection to A/C Compressor Regulator Valve -N280- at the connector -1-.

Remove three mounting bolts -arrows- (tightening torque 25 Nm).

Remove the A/C compressor and tie it to the vehicle with a wire.

Attaching the A/C Compressor to the Bracket

Installation is carried out in the reverse order, when doing this note the following

Before securing A/C compressor, check seating of both bushings -arrow- in bracket or A/C compressor.

Scheme 40

Install one washer each at mounting bolts -arrows- (tightening torque 25 Nm).

After fastening the A/C compressor, check installation position of refrigerant lines, lines must be engaged in bracket (if installed, depending on engine).

After attaching the A/C compressor, also check refrigerant pipes and corresponding holders for adequate clearance with respect to other components, ensuring sufficient distance between belt, holder and pulley.

BELT PULLEY, DENSO VERSION 1

Note. If overload protection of pulley triggers, check the A/C compressor for ease of motion before replacing the pulley. If the A/C compressor creates friction, replace it completely. To remove belt pulley, it depends on engine version if it is necessary to remove A/C compressor from engine. Refer to COMPRESSOR, REMOVING FROM BRACKET . The A/C compressor can be removed and installed at the bracket on engine without opening the refrigerant lines. Mark direction of rotation of ribbed belt using chalk or felt-tip marker before removing. Reversing the direction of rotation of a run-in belt can destroy the belt, refer to [For engine(s) CBRA] RIBBED BELT or refer to [For engine(s) BPY] RIBBED BELT or refer to [For engine(s) CCTA, CBFA] RIBBED BELT or refer to [For engine(s) CBEA] Removal and Installation . There are different versions of the A/C compressor installed. This depends on the engine and the country.

Preparation for Removal

Remove the noise insulation. Refer to Removal and Installation .

Remove the noise insulation frame, if equipped (for example, currently on the Audi A3 Cabrio). Refer to Removal and Installation .

Release tension on ribbed belt and remove it. Refer to [For engine(s) CBRA] Removal and Installation , or refer to [For engine(s) BPY] Removal and Installation , or refer to [For engine(s) CCTA, CBFA] Removal and Installation , or refer to Removal and Installation .

If necessary, remove the A/C compressor from the engine. Refer to COMPRESSOR, REMOVING FROM BRACKET .

Removing

Remove bolt -A- (tightening torque 20 Nm).

Scheme 41

Note. To loosen and tighten bolt -A-, counter-hold it at drive plate -B- using a commercially available pin wrench -C- (pin diameter 5.0 mm). Bolt -A- is to be replaced (because of locking compound). If the belt pulley cannot be removed with A/C compressor still installed, then remove the A/C compressor from the engine. Refer to COMPRESSOR, REMOVING FROM BRACKET .

Carefully and uniformly pry off drive plate -A- using 2 screwdrivers -B-.

Scheme 42

Note. Make sure that the collar for pulley -C- is not damaged when prying off drive plate -A-. There are different versions of pulley -C- and drive plate -A-, therefore note the exact assignment.

Remove circlip -A-.

Scheme 43

Remove pulley -B-.

Installing

Note. Replace circlip -A-. When installing circlip -A-, note that it cannot be bent open more than is necessary for installation. Insert circlip -A- on correct side, the side with beveled insertion edge -C- faces away from A/C compressor (install flat side facing compressor). Ensure proper seating of circlip in groove on compressor flange. Clean compressor flange before fitting the pulley on, pulley must be able to be fitted easily. (fitting must be possible without much force).

BELT PULLEY, DENSO VERSION 2

Special tools and workshop equipment required

1. Shock Absorber Set T10001

Note. Observe notes for removing belt pulley of version 1, these also apply for version 2. Refer to BELT PULLEY, DENSO VERSION 1 . Perform any necessary preliminary work to remove version 1 belt pulley. Refer to BELT PULLEY, DENSO VERSION 1 . Belt pulley is made of plastic and is sensitive to impact, therefore handle it with especial care. If the drive plate overload protection -C- has been triggered, then the drive plate can be pried off belt pulley -D- after removing circlip -A-. A plastic disc -B- may be installed on drive plate of belt pulley -A- to optimize noise reduction. The plastic disc -B- can reduce a clapping (castanet-like) noise which occurs especially at belt pulley in vehicles with Diesel engine in A/C system operating mode Econ (A/C compressor activation switched off); the noise is almost inaudible with A/C system operating at full output. Depending on the control head version, Econ is on when the ECON button lights up and the AC is off.

Removing

Remove the plastic disc -B- from belt pulley -A- (if installed).

Scheme 44

Using a small screwdriver or needle-nose pliers, carefully remove the circlip -A- (which might have rubber disc vulcanized on to it); take extreme care not to damage belt pulley when doing this.

Scheme 45

Hold A/C compressor input shaft -B- firmly in place using a standard Allen wrench or a socket wrench from the T10001 (depending on version of A/C compressor) and rotate drive plate -C- along with belt pulley -D- in direction of arrow -E- (tightening specification: 35 Nm).

Remove drive plate -C-.

Remove circlip -A-.

Scheme 46

Remove pulley -B-.

Installing

Note. Replace circlip -A-. Clean the A/C compressor flange before sliding on the belt pulley. When installing circlip -A-, note that it cannot be bent open more than is necessary for installation.

Install belt pulley -B-.

Insert circlip -A- on correct side, the side with beveled insertion edge -C- faces away from A/C compressor (install flat side facing compressor).

Insert rubber element -D- in belt pulley -B- according to illustration.

When installing drive plate, coat rubber element -D- lightly e.g. with tire mounting paste or soap solution (as sliding compound).

Insert the drive plate -C- far enough into rubber elements -D- (see upper illustration) until it contacts the A/C compressor shaft -B-.

Install the drive plate -C- on the compressor shaft -B- by rotating it in the direction of the arrow -F-.

Tighten drive plate -C- (via belt pulley -D-) to 35 Nm by rotating in direction of arrow -F- using a conventional band wrench (with webbed band). Hold the compressor shaft -B- firmly in place using a commercially available hex wrench or the socket wrench from the T10001.

Install circlip -A- (with rubber disc).

Clean drive plate of belt pulley -A- and glue plastic disc -B- centered onto drive plate (only on A/C compressors without rubber ring on circlip).

BELT PULLEY, DENSO VERSION 3

Note. If overload protection of pulley triggers, check the A/C compressor for ease of motion before replacing the pulley. If the A/C compressor creates friction, replace it completely. Perform preliminary work as for removing belt pulley BELT PULLEY, DENSO VERSION 1 . Belt pulley is made of plastic and is sensitive to impact, therefore handle it with especial care If the drive plate -C- overload protection activates, rotate the pulley -E- using the outer part of the drive plate -C- so that the compressor shaft -B- and the hexagon head on the drive plate -D- (inner part of the drive plate -C-) do not rotate.

Removing

Remove the cap -A-.

Scheme 47

Hold the A/C compressor input shaft -B- for example, with a standard Allen wrench (7 mm) and turn the drive plate -C- together with the pulley -E- in the direction of the -arrow-.

Note. The torque to drive the A/C compressor is transferred to the drive plate -C- via the threaded connection. If, while the A/C compressor is working, the drive plate -C- was attached to the A/C compressor shaft so tight, that it cannot be loosened (the 7 mm Allen wrench -B- cannot transmit the necessary torque) then the A/C compressor must be replaced.

Remove drive plate -C-.

Remove circlip -A-.

Scheme 48

Remove pulley -B-.

Installing

Note. Replace circlip -A-.

Clean A/C compressor flange before sliding on belt pulley -B-.

When installing circlip -A-, note that it cannot be bent open more than is necessary for installation.

Install belt pulley -B-.

Insert circlip -A- on correct side, the side with beveled insertion edge -C- faces away from A/C compressor (install flat side facing compressor).

Clean the compressor shaft thread before mounting the drive plate.

Note. The thread of the new drive plate has already been greased with a specific amount of a grease by the manufacturer.

When installing drive plate, coat rubber element -D- lightly e.g. with tire mounting paste or soap solution (as sliding compound).

Insert rubber element -D- in belt pulley -B- according to illustration.

Press the drive plate rubber element -C- far enough into the pulley -E- until the drive plate -C- until it contacts A/C compressor shaft -B-.

Install the drive plate -C- onto the compressor shaft -B- by rotating it opposite the direction of arrow -arrow-.

Hold the compressor input shaft -B- for example, with a standard Allen wrench (7 mm) and turn the drive plate -C- together with the pulley -E- in the direction of the arrow -arrow-.

A/C COMPRESSOR BELT PULLEY, ZEXEL/VALEO

Note. Observe notes for removing belt pulley for compressor manufactured by Denso version 1, these also apply to this A/C compressor. Refer to BELT PULLEY, DENSO VERSION 1 . Perform any preliminary work as described for removing belt pulley on compressor manufactured by Denso version 1. Refer to BELT PULLEY, DENSO VERSION 1 . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.

Removing Drive Plate

Note. On A/C compressors with part number 1K0 820 803 as of index N, the drive plate splines are bonded to A/C compressor shaft splines. On A/C compressors with part number 1K0 820 803 up to index L, the drive plate splines are not bonded to A/C compressor shaft splines, removing drive plate. On these A/C compressors it may be possible that the drive plate splines are worn off and the A/C compressor is no longer driven. Refer to. In this case, check the A/C compressor for freedom of movement and if necessary replace drive plate, use the repair set 1K0 898 814.

Hold belt pulley -A- firmly in place using a conventional band wrench (with webbed band) and loosen bolt -B-.

Scheme 49

Note. If drive plate overload protection -D- has triggered, the belt pulley turns freely without driving the A/C compressor. Check the A/C compressor for freedom of movement by turning at bolt -B-, replace a A/C compressor with belt pulley that turns with resistance. If compressor moves freely, in this case remove bolts -C- and remove drive plate. Then hold drive plate hub firmly in place using pliers to loosen bolt -B-. If belt pulley splines have been worn away, bolt -B- cannot be loosened (compressor turns along with the bolt). In this case, remove the bolts -C- and tension drive plate with washer -A- (flat side faces outward), washers -B- and bolts -C- (contained in repair set 1K0 898 814) on to A/C compressor shaft.

Then remove bolt -D-.

Remove washer -A- and remove drive plate -A-.

Note. If drive plate -A- has bonded to A/C compressor shaft, install three long bolts -C- in belt pulley -D- through holes of drive plate -A- and then press off drive plate -A- with a convention bolt -B- (bolt with an M8 thread that is flat in the front and has a minimum rigidity class of 10.9). While doing this, hold belt pulley -D- firmly in place using a conventional band wrench (with webbed band). If drive plate -A- has already been replaced once in customer service and was bonded at that time using sealing compound D 154 102 A1, it may be joined so securely to the A/C compressor shaft that it can no longer be pressed off, in this case the entire A/C compressor must be replaced.

In the event the belt pulley is to be replaced, remove circlip and remove belt pulley. Refer to A/C COMPRESSOR BELT PULLEY, ZEXEL / VALEO .

Clean and check the splines on the A/C compressor shaft. If the splines are showing wear, replace the A/C compressor.

Installing drive plate

Clean the splines on the A/C compressor shaft -B-, the belt pulley -A- and the splines on the drive plate -C- (remove any rust, abraded material, old sealant and other particles).

Scheme 50

Clean thread on A/C compressor shaft -B- and the three threads in belt pulley -A- of old bolt locking compound (for example, using a thread tap).

Check the splines on the A/C compressor shaft -B-. If the splines are showing wear, then replace the A/C compressor.

Check the splines on the drive plate -C-. Replace the drive plate if the splines are showing wear.

If necessary, install belt pulley and the corresponding circlip, refer to A/C COMPRESSOR BELT PULLEY, ZEXEL / VALEO .

Coat splines on A/C compressor shaft -B- and drive plate -C- with sealant D 154 102 A1.

Note. Apply sealant sparingly all around, making sure that no sealant reaches the A/C compressor shaft seal -B- (in the A/C compressor). The sealant is also an adhesive, after hardening the drive plate can no longer be removed. The sealant hardens within a certain time period, therefore mount the drive plate within 5 minutes after coating splines with sealant and tighten bolts -C- and -B- to the specified torque, refer to A/C COMPRESSOR BELT PULLEY, ZEXEL / VALEO also within this time.

Install the remaining removed components again in reverse order.

Wait one hour (from mounting the drive plate) before starting the engine.

Note. Sealant requires approximately one hour to attain the necessary rigidity.

A/C COMPRESSOR BELT PULLEY, DELPHI

Note. The Delphi A/C compressor belt pulley cannot be removed separately. If there are complaints, replace the complete A/C compressor. Refer to A/C COMPRESSOR .

AIR QUALITY SENSOR

Note. The Air Quality Sensor -G238- is not installed in all vehicles (optional equipment at this time). air quality sensor is a highly sensitive electronic component that can be damaged if it comes in direct contact with solvents, fuels or chemicals (e.g. impurities may enter through area -A-). Do not install an air quality sensor that may have been stored in a tool box. Do not store a removed air quality sensor in areas that are contaminated with solvents, fuels and certain other chemicals (fluids or gases). Air quality sensor is available in different housings, but functionally they are the same.

Removing and Installing

Lift right side of plenum chamber cover or remove plenum chamber cover. Refer to Removal and Installation .

Disconnect connectors -A- from air quality sensor.

Scheme 51

Rotate air quality sensor 90° and pull air quality sensor -B- upward out of mount.

Terminal assignment in connector -A

1 - B+ (terminal 15)

2 - Ground (terminal 31)

3 - Signal line to the Climatronic control module (the measured value is displayed in the measured value block of the Climatronic control module using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function).

Note. Square wave signal cannot be evaluated using workshop equipment.

AIR INTAKE COVER

Remove the windshield wipers and the cowl panel (plenum chamber cover). Refer to [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation and Removal and Installation .

If installed, disconnect connector from Air Quality Sensor -G238-, refer to AIR QUALITY SENSOR .

Remove bolts -A-.

Scheme 52

Remove cover -B-.

Note. Make sure cover -B- is properly seated, water may flow into intake housing of A/C (heater) unit if cover is not installed correctly. Replace cover if damaged.

AIR INTAKE GRILLE

Remove the cover -B-, refer to AIR INTAKE COVER .

Remove nuts -C-.

Remove the air intake grille -D-.

Note. Make sure the air intake grille -D- is properly seated, water may flow into intake housing of A/C (heater) unit if the grille is not installed correctly. Check seal applied at bottom on cover grille for damage and replace if necessary.

AIR INTAKE HOUSING

Note. The design of the air intake housing is different on vehicles with manually and automatically regulated A/C system. On the air intake housing for vehicles with automatically regulated A/C system, there are again different versions (with and without mount for Fresh Air Intake Duct Temperature Sensor -G89- with one or two control motors for operating recirculating air and air flow door / fresh air door). Up to the end of model year 2007, the air flow door (fresh air door) was moved by Air Flow Door Motor -V71-. From the end of model year 2007, the air flow door motor is being discontinued as a running change. On vehicles without the air flow door motor the air flow door is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to RECIRCULATION DOOR MOTOR . Therefore note the correct allocation of the Climatronic Control Module -J255-. If the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction.

Removing

Remove the instrument panel and the instrument panel cross-member. Refer to Removal and Installation .

Remove A/C unit, refer to HEATING AND A/C UNIT .

Disconnect the connector -A-.

Scheme 53

Mark wire connection to connector -B- (to air flow door motor) and disconnect it (to prevent confusion since connectors -B- and -C- are of identical construction).

Mark wire connection to connector -C- (to recirculation door motor) and disconnect it.

Remove bolts -D-.

Disengage intake housing from A/C unit.

Note. Different versions on vehicles with and without fresh air intake duct temperature sensor. From model year 2006, the fresh air intake duct temperature sensor has been gradually discontinued. On vehicles without this temperature sensor, only the Climatronic control module with part no. as of index M is or may be installed. On vehicles without fresh air intake duct temperature sensor, a Climatronic control module with part no. up to index L installed enters a DTC into the DTC memory.

Installing

Reinstall all removed components in the opposite sequence while observing the following

When attaching air intake housing, make sure mounting points -F- and -G- are seated correctly.

Install the wiring harness so that it cannot come in contact with any moving parts (for example, the motor actuating arm).

AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE

Note. An electric auxiliary air heater is currently installed in vehicles with diesel engine. In this system, the air is supplied with heat energy after it has left the heater core of the heater / A/C unit, in the event a request from the Climatronic Control Module -J255- / or from the A/C Control Module -J301- is present. The electric auxiliary air heater is controlled by the Auxiliary Air Heater Control Module -J604- or by the engine control module (on the 3-stage version by the Low Heat Output Relay -J359- and the High Heat Output Relay -J360-). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (Guided Fault Finding for each engine control module) and refer to the appropriate SYSTEM WIRING DIAGRAMS information. The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the Auxiliary Heater Heating Element -Z35- is via the Auxiliary Air Heater Control Module -J604-. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". On vehicles with Diesel engine manufactured later than November 2006 (running change in production), a 3-stage auxiliary heater heating element is installed, which is actuated via a relay by the respective Engine Control Module (ECM). Refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an auxiliary heater heating element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the auxiliary heater heating element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Functional testing of the electric auxiliary air heater activation on a vehicle with a auxiliary air heater control module is described in Guided Fault Finding of the A/C system using Vehicle Diagnosis, Testing and Information System VAS5051. Measuring value block of auxiliary air heater control module indicates that auxiliary heater is switched on or why no activation is occurring despite a request using Vehicle Diagnosis, Testing and Information System VAS 5051. Functional testing of the electric auxiliary air heater activation on a vehicle with a 3-stage auxiliary heater heating element is described in Guided Fault Finding of the respective Engine Control Module (ECM) using Vehicle Diagnosis, Testing and Information System VAS 5051. At this time, no auxiliary heater is installed in vehicles with gasoline engine, also the parking heater is not activated as auxiliary heater. Only air distribution housings with an opening for an auxiliary heating element are available as replacement parts. In vehicles without auxiliary heater heating element, the opening is sealed by cover for heater core (different versions).

Removing

Remove driver side storage compartment. Refer to Removal and Installation .

Remove center console. Refer to Removal and Installation .

Remove left footwell vent -A- (driver side). Refer to Removal and Installation .

Scheme 54

Remove the bracket -B-. Refer to Removal and Installation .

Remove 4 bolts -A- and remove cover -B-.

Scheme 55

Note. There are different versions of the cover -B- (vehicles with or without an electric auxiliary heater). If lever to left temperature door is located unfavorably so that upper bolt -A- is not accessible, switch ignition on and select a different temperature setting on Climatronic control module for the left side (e.g. Hi setting).

Further procedures for vehicles with auxiliary air heater control module

Switch off ignition.

Disrupt voltage supply to auxiliary heater heating element by pulling out corresponding fuse (100 A at this time), component location of fuse can be found in corresponding wiring diagram, refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Disconnect harness connector -A- from heating element -D-.

Scheme 56

Check between connections -C- B+ and -B- Ground e.g. using a voltage tester, there must no longer be any voltage present (danger of short circuit).

Mark both wire connections to auxiliary heater heating element (risk of interchange, only on vehicles with auxiliary air heater control module).

Note. If connection assignments were interchanged, auxiliary air heater control module can no longer regulate the current and auxiliary heater heating element is continuously supplied with current (unregulated at maximum heating performance).

Disconnect both wire connections -B- and -C- to auxiliary heater heating element (tightening torque of hex nuts 6 Nm) and insulate connection points (danger of short circuit).

Pull auxiliary heater heating element -A- (with auxiliary air heater control module -B-, cannot be tested or replaced individually) from A/C unit (from heater unit).

Scheme 57

Further procedures for vehicles with a 3-stage auxiliary heater heating element (without auxiliary air heater control module)

Switch off ignition.

Remove the hex nuts -A- (tightening specification: 6 Nm).

Scheme 58

Disconnect connector -B- from auxiliary heater heating element -C-.

Pull auxiliary heater heating element -B- out of heating A/C unit (out of heater).

Installing

Now install all removed components in reversed order.

Note. Hex nuts at both wire connections -B- and -C- to auxiliary heater heating element are tightened to 6 Nm (electronics of auxiliary heater heating element are damaged if torque is too great). The nut -A- on the connector -B- and the ground for the auxiliary heater heating element -C- is tightened to 6 Nm. Tightening too much will damage the auxiliary heater heating element.

After installing, check the control and the function of the auxiliary heater heating element using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (on vehicles equipped with A/C) and TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C .

Note. Different versions of the Climatronic Control Module -J255- depending on the time of production, the equipment level and vehicle version. Pay attention to the correct allocation; if this is not OK, then this can lead to DTC entries and complaints regarding the A/C system control, refer to CLIMATRONIC CONTROL MODULE (installation of the different versions of the Climatronic control module).

Removing

Check coding and adaptation of Climatronic control module via the "Replace control module" function of Guided Fault Finding (in the event that Climatronic control module is to be replaced) using Vehicle Diagnosis, Testing and Information System VAS 5051.

Switch off ignition.

On vehicles without Radio-Navigation system or without radio with large control panel

Scheme 59

Remove the trim -A- under the Climatronic control module in the instrument panel and the radio -B-). Refer to Removal and Installation and Removal and Installation .

Carefully lift connecting rib -A- to disengage lugs -B-.

Scheme 60

Reach into center console from above (and below) and disengage Climatronic control module -C- from center console.

On vehicles with Radio-Navigation system or with a radio with large control panel

Scheme 61

Remove radio or radio navigation system. Refer to Removal and Installation .

Remove the trim -B- above theClimatronic control module) in the center of the instrument panel. Refer to Removal and Installation .

Note. Remove the trim -A- under the Climatronic control module only after removing it. Refer to Removal and Installation .

Carefully lift connecting rib -A- to disengage lugs -B-.

Reach into center console from above (and below) and disengage Climatronic control module -C- from center console.

Disconnect connectors -A- to -D- by pressing catches -E- and remove them.

Scheme 62

Note. Climatronic control module is secured in center console by 4 retaining clips -F- (2 each at top and bottom). If Instrument Panel Interior Temperature Sensor -G56- sends incorrect measurements, check intake grille on panel of Climatronic control module (it must not be sealed) and function of Interior Temperature Sensor Fan -V42-. When replacing an Climatronic control module, observe exact allocation (e.g. with or without controls for heated seats, etc.).

Installing

To installed, perform the steps done during removal in reverse order. Note the following

On the Audi A3 Cabrio, apply a felt strip on the Climatronic control module -A- on the right and left side as illustrated -B- (dimensions: 30 x 15 x 1 mm).

Scheme 63

Note. The felt strip -B- is applied to the area with the open surface.

After installing check the DTC memory of the Climatronic control module and erase any displayed malfunction if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform a basic setting, coding, an adaptation and if necessary, the output diagnostic test on the Climatronic control module using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

CONDENSER

Special tools and workshop equipment required

1. Spacer Tube 10 - 222 A /17

Note. Condenser is available in different versions, depending on version of vehicle. The radiator and condenser may have small indentations on the fins even when installed correctly. It is not damage. Do not replace the radiator or condenser because of those small indentations.

Removing

Evacuate the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT .

Remove front bumper. Refer to Removal and Installation .

Disconnect refrigerant lines from condenser, refer to REFRIGERANT LINES, DISCONNECTING FROM CONDENSER .

The following additional work may be necessary to remove condenser, depending on engine version

1. Disengage front end module from longitudinal member and pull forward approximately 10 cm (for example, in vehicles with 2.0L gasoline engine), then proceed as follows

Disengage bracket for refrigerant lines on right longitudinal member -arrow-.

Scheme 64

Protect front corners of both fenders from damage, for example, with adhesive tape -1-.

Scheme 65

Mark position of front end module to both fender flanges -2- for example, using a suitable pin -3-.

Remove mounting bolts -4- of front end module at fender flanges.

Remove upper mounting bolt -3- of front end module at both longitudinal members and insert a long bolt -4- (for example, M10 x 120) into upper mount point on left and right longitudinal member.

Scheme 66

Remove one of the two lower mounting bolts -5- of front end module at both longitudinal members and mark position of front end module -2- to mounting points on left and right longitudinal members e.g. using a suitable pin -1-.

Remove the remaining mounting bolts -5- for front end module (on longitudinal members). Refer to Removal and Installation .

Carefully pull front end module toward front over bolts -1-.

Scheme 67

Secure the left and right front end modules with an additional screw -2- (for example, M 10 x 120) and a 10 - 222 A /17.

Remove the radiator fan -B- with the mount (for example on 2.0L gasoline vehicles). Refer to RADIATOR AND RADIATOR FAN COMPONENT OVERVIEW .

Procedure continued for all vehicles

Remove bolts -A- and disengage radiator (with condenser) -B- from front end module -C-. Refer to RADIATOR AND RADIATOR FAN COMPONENT OVERVIEW .

Scheme 68

Remove bolts -A- and -B- (tightening torque 5 Nm).

Scheme 69

Loosen the condenser -C- from the radiator -D

Remove condenser -C- upward.

Installing

Installation is carried out in the reverse order, when doing this note the following

Make sure that sealing strips -E- and -F- are adhered correctly to condenser -C- (not installed in all versions).

Note. The removed condenser contains refrigerant oil that must be returned to the refrigerant circuit (with the new condenser), refer to COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT . Depending on version of vehicle and of radiator, a spacer -G- may be installed, replace it if necessary according to illustration. Depending on version of vehicle, a stone deflector -B- may also be secured with clips -C- at lower area of condenser -A-.

Evacuate and re-charge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

CONNECTING POINTS IN REFRIGERANT LINE, DISCONNECTING AND CONNECTING

Note. This connecting point is not installed in all vehicles (for example, installed in vehicles with 6-cylinder engines at this time).

Loosening

Discharge refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Remove the noise insulation. Refer to Removal and Installation .

Remove bolt -A- (tightening torque 10 Nm), counterhold at connecting point using a suitable tool when doing this (but do not twist refrigerant lines).

Scheme 70

Loosen the clamp -B-.

Pull lines apart.

Note. Seal off any open lines with a cap to prevent dirt and moisture from getting in.

Assembling

Assembling is carried out in the reverse order, when doing this note the following

Replace O-ring seal -C-, refer to REFRIGERANT CIRCUIT O-RINGS ;.

Check fitted pin -E- and bushing -F- for damage and proper seating.

Note. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . Check O-ring seals for proper seating in groove -D- of respective refrigerant line. Install refrigerant pipes such that they are not strained.

Evacuate and recharge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

AIR FLOW DOOR MOTOR AND POTENTIOMETER

Special tools and workshop equipment required

1. Connector Test Kit V.A.G 1594 C

Vehicles with automatically regulated A/C system

Note. To the end of model year 2007, the back pressure door motor is being discontinued as a running change. On vehicles without the back pressure door motor, the Air Flow Door -V71- (fresh air door) is operated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to RECIRCULATION DOOR MOTOR . Therefore note the correct allocation of the Climatronic Control Module -J255-. if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction. refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Not installed on vehicles with manually regulated A/C system. Air flow door is not installed on vehicles with a manual climate control system. Check the motor: Connect both terminals 5 and 6 in control motor connector to 12 V (DC), the motor moves in one direction until stop, the direction of rotation changes by interchanging B+ and Ground. Use an adapter cable, refer to ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS . Perform Basic Setting of A/C system after installing a new control motor using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Using Guided Fault Finding it is possible to check the control for the A/C electrical components, for example to check for interchanging during the basic setting. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". After installing a new control motor, check activation by Climatronic control module and function of control motor (correct position of air flow door for recirculating and fresh air mode) using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Air Flow Door Motor can only be removed without difficulty in fresh air mode stop and installed only in this position. If the motor stops in a different position and can no longer be moved electrically into the fresh air mode stop, replace it.

Removing

Remove the glove compartment. Refer to Removal and Installation .

If necessary, switch ignition on, select operating mode Defrost on the Climatronic control module (control motor is always set to fresh air mode position in this operating mode) and wait until control motor has reached its fresh air mode end position.

Switch off ignition.

Disengage catches -D- and -E- for bracket -A- on intake housing and remove bracket -A-.

Scheme 71

Remove recirculation door motor, refer to RECIRCULATION DOOR MOTOR .

Mark connector to recirculation door motor (to prevent confusion with connector to air flow door motor).

Remove positioning motor -A- from air intake shroud.

Scheme 72

Note. Connection between control motor toothed gears and air flow door is designed so that control motor can be removed without difficulty only in the fresh air mode position. If motor is found in a different position and can no longer be moved, motor cannot be simply pulled off, rather it must be loosened first with great force from mounting points -B-, ensure that toothed gear -C- is not damaged when doing this.

Installing

Note. Motor as replacement part is delivered in the fresh air mode position, only when toothed gear -A- contacts stop -B- can it then be connected onto toothed gear of air flow door. If a motor was removed in a different position or activated in the removed state, it cannot be installed. If control motor toothed gear -A- is not located at stop -B- fresh air mode, connect terminals 5 and 6 of control motor via a 5 A fuse to a 12 V battery e.g. using an adapter cable, refer to ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS or an adapter wire from V.A.G 1594 C.

Control motor moves in one direction until it reaches stop, direction of rotation can be changed by interchanging B+ and Ground.

Activate control motor for as long until toothed gear -A- reaches stop fresh air mode -B-.

Before installing control motor, check bearing of air flow door in intake housing and of toothed gear -C- (air flow door is opened, fresh air mode).

Switch off ignition.

Connect air flow door motor to vehicle wiring harness (make sure connectors are allocated correctly).

Open the air recirculation flap -E-.

Scheme 73

Reach into intake opening for recirculating air mode and bring air flow door -A- into fresh air mode position (intake opening for recirculating air mode is closed).

Insert motor -B- into mounts -C- in opposite direction of arrow and onto toothed gear -D-.

Scheme 74

So that toothed gear on motor -A- can be slid on toothed gear of air flow door, short tooth -C- of motor toothed gear must align with short tooth interval -D- of toothed gear on shaft of air flow door -B-.

Scheme 75

Install recirculation door motor, refer to RECIRCULATION DOOR MOTOR .

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Install the bracket -A-, make sure the guides on the bracket -B- are inserted correctly into the intake housing mount -C- and that the bracket is engaged correctly in both catches -D- and -E-.

Check both motors, it must be held in its position by bracket -A-, if it is not installed free of play, use some foam to rectify play if necessary, attaching it to inside of mounting points -F- of bracket -A-.

Note. The position of the air flow door motor and of the recirculation door motor is no longer visible when the glove compartment is installed. Make sure they are working correctly before installing the glove compartment. If both toothed gears (on air flow door motor and air flow door) assembled in the incorrect position, air flow door will not reach its two end positions (may be detected as a malfunction via Basic Setting function) or motor does not run cleanly and without hitching.

Perform Basic Setting of A/C system after installing control motors and then check DTC memory of A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Switch ignition on.

Activate air flow door motor and recirculation door motor via Climatronic control module as follows for as long until toothed gear reaches stop recirculating air mode (this illustration depicts air flow door -A- at stop for fresh air mode) and then check position of air flow door, it must be closed.

Then select recirculating air mode function on Climatronic control module.

Recirculation door motor opens door -E- and air flow door motor sets air flow door -A- into position air intake opening for recirculating air mode open.

Wait until both motors have reached their end positions.

Select fresh air mode function e.g. via operating mode Defrost (controls motors are always set to fresh air mode position in this operating mode).

Air flow door motor sets air flow door -A- into position air intake opening for recirculating air mode closed, recirculation door motor sets door -E- into a position specified by Climatronic control module.

Wait until both motors have reached their end positions.

Install the remaining removed parts again in reverse order.

Note. Position of air flow door -A- is visible via air intake opening in plenum chamber (remove plenum chamber cover) with recirculating air door -E- closed. For air flow regulation, fresh air intake channel is closed partially via air flow door -A- at high vehicle speed (from approximately 80 km/h) by Climatronic control module (position of recirculating air door -E- is specified by Climatronic control module). So that change in noise of Fresh Air Blower -V2- by the changed air intake during change-over from fresh air mode to recirculating air mode or vice versa (change-over occurs e.g. in vehicles with Air Quality Sensor -G238- automatically which air pollution is encountered) is reduced, activation of air flow door motor and of air recirculation door motor occurs as follows: When switching from fresh air to recirculation mode, the recirculation door -E- is first opened, then the fresh air intake channel is closed via the air flow door -A-. When switching from recirculation to fresh air mode, the fresh air intake channel is first closed by the air flow door -A-, then the air recirculation flap -E- is closed. In partially recirculating air mode, recirculating air door -E- is opened and air flow door (fresh air door) -A- is brought into an intermediate position by Climatronic control module (fresh air and recirculating air intake channel are slightly opened simultaneously). This achieves improved cool-off in certain temperature ranges and simultaneously draws in a certain portion of fresh air as well.

CENTRAL AIR DOOR MOTOR

Vehicles with automatically regulated A/C system

Note. Not installed on vehicles with manually regulated A/C system. Central Air Door Motor -V70- is operated via a flexible shaft on vehicles with manually regulated A/C system. Check the motor: Connect both terminals 5 and 6 in control motor connector to 12 V (DC), the motor moves in one direction until stop, the direction of rotation changes by interchanging B+ and Ground. Use an adapter cable, refer to ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS . Perform Basic Setting of A/C system after installing a new control motor using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Using Guided Fault Finding it is possible to check the control for the A/C electrical components, for example to check for interchanging during the basic setting. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Removing

Remove the instrument panel. Refer to Removal and Installation .

Reach through opening between left side of A/C unit and central tube (instrument panel cross member) and disconnect connector -A-.

Scheme 76

Mark connector -A- if necessary (to prevent confusion in the event several connectors are disconnected at the same time).

Remove bolts -B-.

Remove control motor -C-.

Installing

Insert stub -D- into socket -E-.

Reinstall all removed components in the opposite sequence while observing the following

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Check DTC memory of Climatronic Control Module -J255- and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

DEFROSTER DOOR MOTOR

Vehicles with automatically regulated A/C system

Note. Not installed on vehicles with manually regulated A/C system. The defroster door is operated via a flexible shaft on vehicles with a manual climate control system.

Removing

Remove dash panel complete with dash panel cross member. Refer to Removal and Installation .

Scheme 77

Remove the bracket -A- and the Data Bus On Board Diagnostic Interface -J533- (near the steering column, attached to the bracket -A-). Refer to Removal and Installation and [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation .

Mark connector -C- to control motor (to prevent confusion with other connectors of same construction).

Scheme 78

Disconnect connector -C- from Defroster Door Motor -V107-.

Remove bolts -A-.

Remove control motor -B-.

Disengage control motor lever -E- from connecting rod -D-.

Installing

Note. Lever -E- on control motor and connecting rod -D- are color-coded, they are colored blue for Defroster Door Motor.

Reinstall all removed components in the opposite sequence while observing the following

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Check DTC memory of Climatronic control module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

LEFT TEMPERATURE / TEMPERATURE REGULATOR DOOR MOTOR

Left Temperature Door Motor -V158- on vehicles with automatically regulated A/C system

Temperature Regulator Door Motor -V68- on vehicles with manually regulated A/C system

Note. One motor each for the left and right temperature doors is installed on vehicles with automatically regulated A/C system. Vehicles with manually regulated A/C system: both temperature doors are operated by Temperature Regulator Door Motor -V68-, therefore the name for this control motor is different in Guided Fault Finding and in wiring diagram. Refer to Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Removing

Remove dash panel complete with dash panel cross member. Refer to Removal and Installation .

Remove the bracket -A- and the Data Bus On Board Diagnostic Interface -J533- (near the steering column, attached to the bracket -A-). Refer to Removal and Installation and [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation .

Mark connector -C- to control motor (danger of interchange with other connectors of same construction).

Scheme 79

Disconnect connector -C- from Left Temperature Door Motor / Temperature Regulator Door Motor.

Remove cover -A- (from heater core).

Remove bolts -D-.

Remove control motor -B-.

Disengage control motor lever -E- from connecting rod -F-.

Installing

Note. Currently, lever -E- on control motor is colored gray and connecting rod -F- colored black.

Reinstall all removed components in the opposite sequence while observing the following

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Check DTC memory of Climatronic control module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

RECIRCULATION DOOR MOTOR WITHOUT AIR FLOW DOOR MOTOR

Removing

Remove the glove compartment. Refer to Removal and Installation .

Remove bolts -B-.

Scheme 80

Disengage the motor -A- from mount -D-.

Disengage control motor pin -E- from curved washer mount -F-.

Mark connector -C- if necessary (to prevent confusion in the event several connectors are disconnected at the same time) and disconnect it.

Remove control motor -A-.

Installing

Check controls and function of recirculation door -C- and air flow door (fresh air door) -B- by rotating curved washer -A-, while doing this check for proper seating of pins installed on levers in grooves of curved washer -A-.

Scheme 81

Set curved washer -A- so that connecting element of control motor can be inserted.

Note. On vehicles without Air Flow door Motor -V71-, the recirculation door and the air flow door (fresh air door) are moved via a curved washer by the Recirculation door Motor -V113-. So that the time to reach air recirculation mode is as short as possible, the curved washer is constructed in a such a way that the recirculation door is open and the air flow door is closed in both control motor end stops. Recirculation door motor stands approximately in the center position, refer to RECIRCULATION DOOR MOTOR in fresh air mode (recirculation door closed and air flow door open).

Connect connector -C- to motor -A-.

Route the wiring harness to connector -C- so that it cannot come in contact with any moving parts (e.g. with the lever on intake housing).

Insert control motor pin -E- into curved washer mount -F-.

Note. The pin of control motor shaft -E- may only by installed in the position in which it can be inserted without force in curved washer mount -F-. If pin -E- can only be slid in with pre-load, check motor shaft, it may be offset by 270° and standing at the other stop. If pin of control motor shaft -E- is not in the position in which it can be inserted, connect control motor to vehicle wiring harness. Switch ignition on and select a setting in which the control motor is brought to the center position (e.g. fresh air mode) on the Climatronic Control Module -J255-. Wait until control motor has reached the desired position and then switch ignition off. If pin of control motor shaft -E- is not in the position in which it can be inserted, connect terminals 5 and 6 of the removed control motor via a 5A fuse to a 12 V battery e.g. using adapter lead ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS (or an adapter lead from V.A.G 1594/C). Rotate control motor for as long until the shaft is located in a position in which it can be connected without initial force (approximately the center position), the turning direction can be reversed by swapping Plus and Minus.

Place control motor -A- into mount -D-.

Install bolts -B-.

Reinstall all removed components in the opposite sequence while observing the following

Check DTC memory of Climatronic Control Module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Note. In the event of problems with moisture in passenger compartment, additionally check recirculated-air door (must close completely).

RECIRCULATION DOOR MOTOR WITH AIR FLOW DOOR MOTOR

Removing

Remove the glove compartment. Refer to Removal and Installation .

Mark connector -A- if necessary (to prevent confusion in the event several connectors are disconnected at the same time).

Disconnect the connector -A-.

Scheme 82

Disengage catches -C- and -D- for bracket -B- on intake housing and remove bracket -B- (toward rear).

Remove positioning motor -A- from air intake shroud.

Scheme 83

Installing

Check shaft of recirculation door -C- before installing control motor -A-.

Set shaft -C- so that connecting element of control motor -D- can be inserted.

Insert control motor with connecting element -D- into shaft -C- and mounts at intake housing -B-.

Install the bracket -A-, make sure the guides on the bracket -B- are inserted correctly into the intake housing mount -C- and that the bracket is engaged correctly in both catches -D- and -E-.

Check both motors, which are being held in position by the bracket -A-. Make sure they are not loose. Insert a piece of foam into the inside of the mounting points -F- on the bracket -A-.

Reinstall all removed components in the opposite sequence while observing the following

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Check DTC memory of Climatronic control module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Note. In the event of problems with moisture in passenger compartment, additionally check recirculated-air door (must close completely).

RIGHT TEMPERATURE DOOR MOTOR

Vehicles with automatically regulated A/C system

Note. Both temperature doors are operated by Temperature Regulator Door Motor -V68-, therefore this motor is not installed on vehicles with a manual climate control system. Check the motor: Connect both terminals 5 and 6 in control motor connector to 12 V (DC), the motor moves in one direction until stop, the direction of rotation changes by interchanging B+ and Ground. Use an adapter cable, refer to ADAPTER CABLE FOR ACTIVATING CONTROL MOTORS . Perform Basic Setting of A/C system after installing a new control motor using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. Using Guided Fault Finding it is possible to check the control for the A/C electrical components, for example to check for interchanging during the basic setting using Vehicle Diagnosis, Testing and Information System VAS 5051.

Removing

Remove the glove compartment. Refer to Removal and Installation .

Remove front passenger side footwell vent -A- (in order to improve accessibility to control motor -B-).

Scheme 84

Remove bolts -B-.

Scheme 85

Remove control motor -C-.

Disengage control motor lever -E- from connecting rod -D-.

Disconnect the connector -A-.

Installing

Note. Lever -E- on control motor and connecting rod -D- are color-coded, they are colored black for Right Temperature Door Motor -V159-.

Reinstall all removed components in the opposite sequence while observing the following

Install the wiring harness so that it cannot come in contact with any moving parts (e.g. the actuating arm of the control motor).

Check DTC memory of Climatronic control module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

DRYER CARTRIDGE

Note. The reservoir may be attached to or integrated in the condenser, depending on the version of the condenser. Replace an attached reservoir. Refer to FLUID RESERVOIR . There are different versions of the condenser with the dryer cartridge installed inside it.

DRYER CARTRIDGE, DENSO CONDENSER

Note. The dryer cartridge -D- and the O-ring -B- are the same in all condenser versions. Should a repair set not be available for the Denso condenser, either replace the condenser completely or use the parts from the repair set from another condenser (in this example, from the repair set from the Denso condenser installed in the Audi A4 from MY 2008). Clean the plastic screw -A-, the dryer carrier -C- and the filter -E- before using them again.

Removing

Switch off ignition.

Remove the front bumper. Refer to Removal and Installation .

Discharge refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Remove the plastic screw -A- (tightening specification: 2 Nm).

Check the refrigerant circuit pressure using a pressure gauge from the A/C Service Station. Refer to A/C SERVICE STATION .

Note. Depending on the version of the vehicle (of the front end module) it may also be necessary to loosen the condenser from the front end module in order to remove and install the dryer cartridge. Refer to CONDENSER .

Remove the dryer carrier -C- and the dryer cartridge -D- from the condenser.

Pull the filter -E- out of the condenser using, for example, a commercially available pick-up tool.

Note. Seal the open connection on the condenser with the plastic screw -A- to prevent dirt and moisture from getting in.

Installing

Installation is done is reverse order, observe the following

1. Check the reservoir on the condenser above the opening -F- for dirt.
2. Make sure the reservoir thread -F- on the condenser is not dirty or damaged.
3. Replace the plastic screw -A-, the dryer carrier -C-, the dryer cartridge -D-, the filter -E- and the O-ring -B-.
4. Coat the O-ring -C- lightly with refrigerant before installing, refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) .
5. Make sure the O-ring -B- fits correctly inside the groove on the plastic screw -A-.
6. Keep the dryer cartridge -D- sealed in its air-tight package as long as possible. Open the package just before installing the dryer cartridge into the condenser. The dryer cartridge absorbs moisture in a very short time and become unusable.

Install the filter -E- with the correct side into the condenser reservoir.

Take the dryer cartridge -D- out of its package and install it into the dryer carrier -C-.

Install the dryer cartridge -D- and dryer carrier -C- into the condenser reservoir.

Install the plastic screw -A- (tightening specification: 2 Nm).

Install the front bumper. Refer to Removal and Installation .

Install remaining components.

Discharge and fill the refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

DRYER CARTRIDGE, MODINE CONDENSER

Note. The reservoir may be attached to or integrated in the condenser, depending on the version of the condenser. Replace an attached reservoir. Refer to FLUID RESERVOIR .

Removing

Switch off ignition.

Remove the front bumper. Refer to Removal and Installation .

Discharge refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Remove the adhesive sticker from the cap -1-.

Scheme 86

Note. Depending on the version of the vehicle (of the front end module) it may also be necessary to loosen the condenser from the front end module in order to remove and install the dryer cartridge. Refer to CONDENSER .

Remove the cap -1-.

Press the cap -1- into the reservoir.

Scheme 87

Check the refrigerant circuit pressure using a pressure gauge from the A/C Service Station. Refer to A/C SERVICE STATION .

Remove the snap ring -arrow- and pull the cap -1- off the condenser -2- using an M12. screw.

Remove the dryer cartridge using a commercially available pick-up tool -in direction of arrow- from the condenser.

Scheme 88

Make a welding wire (2 mm) to the following dimensions.

Scheme 89

a - 380 mm

b - maximum 7 mm

c - maximum 6 mm

Hook the welding wire to the strainer exactly as illustrated to prevent damaging the condenser.

Scheme 90

Carefully remove the filter (strainer) -2- from the condenser with the welding wire -1-.

Note. Seal the open connection on the condenser with the cap -A- to prevent dirt and moisture from getting in.

Installing

Installation is done is reverse order, observe the following

1. Check the reservoir on the condenser -2- above the opening for dirt or damage to the sealing surfaces.
2. Replace the cap -1- and its seal, the dryer cartridge and the filter (strainer).
3. Coat the seal on the cap -1- lightly with refrigerant before installing. Refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) .
4. Make sure the seal fits correctly inside the cap -1-.
5. Keep the dryer cartridge sealed in its air-tight package as long as possible. Open the package just before installing the dryer cartridge into the condenser. The dryer cartridge absorbs moisture in a very short time and become unusable.

Install the filter (with the strainer) -2- with the correct side into the condenser reservoir.

Remove the dryer cartridge from its original package.

Insert the dryer cartridge into the condenser reservoir.

Install the cap -1-.

Install the snap ring -arrow-.

Install the cap -1-.

Install remaining components.

Discharge and fill the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

DUST AND POLLEN FILTER

Note. Dust and pollen filter change interval, refer to MAINTENANCE, DIAGNOSIS and refer to EVACUATING REFRIGERANT CIRCUIT . Dust and pollen filter is available in different versions without activated charcoal insert (for vehicles without Air Quality Sensor -G238-) and with activated charcoal insert (for vehicles with Air Quality Sensor -G238-). Clean area of dust and pollen filter in housing of A/C (heater) unit before installing a new filter. On vehicles with driving school equipment, pedals of driving school equipment must be removed if necessary (depending on version, service disconnect points are present on driving school pedals).

Remove screw clips -A- (different versions -C- and -D-) and remove insulation mat -B-.

Scheme 91

Cover the carpet with paper in the area under the dust and pollen filter.

If necessary, remove bolts -A- (not installed in all vehicles, they secure cover -B- in the event lugs -D- no longer hold).

Scheme 92

Slide the cover -B- in direction of arrow -C- and remove it.

Remove dust and pollen filter -A- out of shaft -B- of air conditioner (heating).

Scheme 93

Clean heating and A/C unit via shaft -B- (e.g. using a vacuum cleaner) after removing dust and pollen filter.

EVAPORATOR

Remove A/C unit, refer to HEATING AND A/C UNIT .

Remove attachments from heating and A/C unit, refer to ATTACHMENTS - MANUALLY REGULATED A/C SYSTEM or ATTACHMENTS - AUTOMATICALLY REGULATED A/C SYSTEM .

Disassemble the A/C unit. Refer to A/C UNIT .

Disassemble evaporator housing, refer to EVAPORATOR HOUSING .

Remove evaporator -A- from lower section of evaporator housing.

Scheme 94

Note. Before inserting evaporator, check condensation water drain, clean if necessary. Before inserting evaporator, clean evaporator housing (and the evaporator if necessary).

When inserting evaporator -A- into lower section of evaporator housing and when assembling both housing halves, make sure the seal -F- is not damaged.

Check seal -F- (it must be glued all around) before inserting evaporator.

Place bracket -C- and seal / insulation -B- onto connecting pipe of evaporator -D- and -E-.

Insert evaporator -A- into lower section of evaporator housing according to illustration.

Note. After assembling both housing halves, check seal / insulation -B- for correct seating at pass-through for both refrigerant lines -D- and -E-. Check seating of bracket -C- on both refrigerant lines -D- and -E- for correct seating. If heat protection insulation -B- is missing or not installed correctly, it can cause reduced performance of the A/C system (change of adjusted control characteristics of expansion valve due to radiant heat). The removed evaporator contains refrigerant oil that must be returned to the refrigerant circuit (with the new evaporator). Refer to RECEIVER OR ACCUMULATOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT .

EXPANSION VALVE

Note. After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.

Removing

Discharge refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Disconnect refrigerant lines from expansion valve, refer to REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE .

Remove bolts -A- (tightening torque 10 Nm).

Scheme 95

Pull expansion valve -B- out of heat protection insulation -C-.

Note. Seal all open lines and connections on evaporator with suitable caps (avoid dirt and moisture from entering the system).

Installing

Installation is carried out in the reverse order, when doing this note the following

Replace O-rings seals -D- and -E-, refer to REFRIGERANT CIRCUIT O-RINGS .

Make sure that O-rings -D- and -E- are properly seated on connecting pipes to evaporator -F- and -G-.

Note. Expansion valve is available in different versions (same housing but a different control characteristic), therefore ensure the exact allocation. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . If heat protection insulation -C- is missing or not installed correctly, it can cause reduced performance of the A/C system (change of adjusted control characteristic of expansion valve due to radiant heat).

Evacuate and re-charge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM

Note. Vehicles with manually regulated A/C system, a Fresh Air Blower Series Resistor With Fuse -N24- is installed in place of the Fresh Air Blower Control Module -J126-. Removing and installing Fresh Air Blower Series Resistor With Fuse, refer to FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM . Note that there are different versions of fresh air blower for vehicles without A/C (only with heater), with a manual or automatic climate control system. Removing and installing fresh air blower on vehicles with a manual climate control system, refer to FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM . Up to model year 2007, heating and A/C units were installed on which the fresh air blower control module and the Fresh Air Blower -V2- were cast with each other in the housing and could not be replaced separately. Refer to FRESH AIR BLOWER CONTROL MODULE AND FRESH AIR BLOWER . As of model year 2007, heating and A/C units were introduced on which the fresh air blower control module and the fresh air blower can be replaced separately, refer to FRESH AIR BLOWER CONTROL MODULE .

FRESH AIR BLOWER CONTROL MODULE AND FRESH AIR BLOWER

Removing

Remove the glove compartment. Refer to Removal and Installation .

Remove screw clips -A- (different versions -C- and -D-) and remove insulation mat -B-.

Remove bolt -A- (if present).

Scheme 96

If necessary, remove cable ties which bind wiring harness to fresh air blower housing -C-.

Disengage locking mechanism -B- and rotate fresh air blower housing -C- in direction of arrow.

Note. Connection between fresh air blower housing -C- and A/C unit may be sealed with sealing compound, in this case a great use of force is required for rotating. Fresh air blower control module and fresh air blower are installed in housing -C-. On the version that was installed up to model year 2007, both components were cast with each other and thus cannot be replaced separately.

Remove fresh air blower housing -C- from the A/C unit.

Disconnect connector -D-.

Installing

Reinstall all removed components in the opposite sequence while observing the following

Note. When installing, make sure the fresh air blower fits correctly inside the A/C unit. After installing, check seat of fresh air blower housing in A/C unit and function of fresh air blower control module.

Check DTC memory of Climatronic Control Module -J255- and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

FRESH AIR BLOWER CONTROL MODULE

Note. Fresh Air Blower Control Module -J126- can be replaced separately only on the version on which the two components are no longer cast with each other (running change in production as of model year 2007). The fresh air blower control module replacement part is available in different versions. Be sure to use the right one. With ignition switched on and Fresh Air Blower -V2- actuated, fresh air blower control module connects B+ from terminal 4 of connector -C- to terminal 1 of connector -B-. Fresh air blower speed is regulated by fresh air blower control module via the ground connection between terminal 2 connector -B- and terminal 3 of connector -C-. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" and refer to the appropriate SYSTEM WIRING DIAGRAMS information.

Removing

Remove the glove compartment. Refer to Removal and Installation .

Remove screw clips -A- (different versions -C- and -D-) and remove insulation mat -B-.

Disconnect connectors -B- and -C-.

Scheme 97

Remove bolt -A-.

Remove fresh air blower control module -D- from mount in fresh air blower.

Installing

Reinstall all removed components in the opposite sequence while observing the following

Note. When installing, make sure the fresh air blower control module -D- fits correctly inside the fresh air blower mount. Make sure the fresh air blower control module and fresh air blower are working properly after they are installed.

Check DTC memory of Climatronic control module and erase malfunctions displayed if necessary using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Perform Basic Setting and output Diagnostic Test Mode (DTM) of A/C system and check DTC memory again using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

HEATING AND A/C UNIT

Special tools and workshop equipment required

1. Hose Clamps, Up to 40 mm. 3093
2. Hose Clamps Up to 25 mm dia.3094
3. Hand pump Cooling system tester V.A.G 1274/ (and corresponding adapter)
4. Compressed air gun, commercially available

Removal

Note. Before disconnecting battery, obtain anti-theft radio security code if necessary. On vehicles with electrically adjustable seats, move the seats back as far as possible before disconnecting the battery. Refer to Removal and Installation . When removing bolts, take note of the length and assignment of bolts for re-installation. All cable ties opened or cut during removal of heating A/C unit must be reinstalled at the same locations during installation. Depending on vehicle equipment and on engine, heat insulation has been applied to coolant hoses, these must not be damaged and must be re-applied after installing.

Evacuate the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Switch off ignition.

Protect driver and front passenger seats using seat covers.

Disconnect battery, refer to REMOVAL AND INSTALLATION .

Release pressure in cooling circuit by opening the cap on coolant expansion tank, refer to [For engine(s) CBRA] General Information , or refer to [For engine(s) BPY] General Information , or refer to [For engine(s) CCTA, CBFA] General Information , or refer to [For engine(s) CBEA] General Information .

Remove the components that hinder access to the mounting bolts for refrigerant lines -A- on expansion valve and to coolant hoses to heater core in engine compartment.

Scheme 98

Note. Depending on engine and version of vehicle, it may be necessary to loosen or to remove the following components (top engine cover, pressurized air pipe to throttle valve part and depending on engine the intake manifold, etc.). Refer to [For engine(s) CBRA] Removal and Installation or refer to [For engine(s) BPY] Removal and Installation or refer to [For engine(s) CCTA, CBFA] Removal and Installation or refer to [For engine(s), CBEA] Removal and Installation . Depending on the engine (for example, on certain 2.0L diesel engines and depending on the exhaust system) it may be necessary to remove the plenum chamber cover and the front wall of the plenum chamber -A- in order to be able to remove the heat shield and to remove the refrigerant lines from the expansion valve and the coolant hoses from the heat exchanger. Refer to Removal and Installation . The heat shield -B- is available in different versions. For version 1, sheet metal nuts -A- must be removed and heat shield -B- disengaged from vehicle. On version 2, clamping washers -A- and clamp -C- must be removed and heat shield -B- disengaged from vehicle. After disconnecting coolant hoses, remove heat shield -B- completely. For the sake of clarity, the illustrations show the heat shield -B- with the engine removed.

Loosen the heat shield -B- from the front of the plenum chamber and from the bulkhead and move it to the side, or remove it completely.

Slide a thermal protective cover -D- and -E- as far back as possible until it is possible to installed the 3093 -F- onto the coolant hoses -A- and -B-.

Scheme 99

Mark arrangement of coolant hoses -A- and -B-.

Scheme 100

Note. The heater core is designed for a specific coolant flow direction, therefore coolant hoses must be connected on the proper sides (coolant hose -A- supply from cylinder head, coolant hose -B- return to coolant pump). The coolant hose arrangement is the same in both vehicles without and with A/C, this illustration shows a vehicle with A/C. Bleed the coolant circuit. Refer to [For engine(s) CCTA, CBFA] General Information .

If necessary, clamp off vent hose (from upper connection -A- to coolant expansion tank).

Cover the area beneath connections for coolant hoses -A- and -B-, for example, with a paper towel.

Clamp off coolant hoses to heater core of heating A/C unit (e.g. using 3093) and remove them.

Connect one section of hose -A- on to upper connection.

Scheme 101

Hold a container -B- under the lower connection -C-.

Using a compressed air gun, carefully blow coolant out of heater core (into container -B-).

Disconnect refrigerant lines from expansion valve, refer to REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE and secure (e.g. with cable tie) so they do not interfere during installation.

Note. Seal open line connections (against dirt and moisture penetration). Uses the caps from the replacement evaporator to seal off the open connections on the expansion valve or on the evaporator.

Remove the glove compartment, the driver side storage compartment, the center console and the instrument panel. Refer to Removal and Installation .

Note. To prevent the instrument panel shell from damage, instrument panel should be placed on a clean work bench which is covered with clean cardboard.

Remove the gas pedal module. Refer to ACCELERATOR PEDAL MODULE WITH THROTTLE POSITION SENSORS .

Remove the left and right vents -C-.

Scheme 102

Fold back the carpet on the driver and front passenger sides so that the vents for the rear footwells can be removed -A- and -B-. Refer to Removal and Installation .

Remove both rear footwell vents -A- and -B-.

Remove fresh air blower. Refer to FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM

Vehicles with manually regulated A/C system: remove A/C Control Module -J301- (do not remove base plate for controls), refer to HEATER AND A/C SYSTEM CONTROLS .

Remove the instrument panel and the instrument panel cross-member. Refer to Removal and Installation .

Remove Data Bus On Board Diagnostic Interface -J533- (secured to bracket -A- in area of steering column). Refer to [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation .

Remove bolts -B- and release bracket -A- from A/C unit (bracket remains on wiring harness secured to vehicle).

Remove both bolts -A- on bracket for wiring harness -B-.

Scheme 103

Disconnect the connector -C-.

Remove condensation drain from A/C unit, refer to CONDENSATE DRAIN HOSE .

Loosen securing ties of wiring harness on A/C unit.

On vehicles with an electric auxiliary heater (on vehicles with Diesel engine), disconnect wire connections to voltage supply for the Auxiliary Heater Heating Element -Z35-. Refer to AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE .

Disconnect all electrical connections between vehicle wiring harness and the A/C unit electrical components on connectors.

Note. The wiring harness air conditioner is removed together with the A/C unit.

Carefully pull right side of A/C unit slightly toward rear (far enough that bolt -B- on right bracket -A- can be loosened).

Scheme 104

Note. Only pull carefully on A/C unit so that bracket -A- does not break. To loosen bolt -B-, reach between A/C unit and floor mat on right wheel housing (to make this possible, fresh air blower has been removed earlier).

Remove bolts -B- and release bracket -A- from A/C unit (bracket remains on wiring harness secured to vehicle).

Disengage both flanges for coolant pipes to heater core -A- and for expansion valve (to evaporator) -B- from pass-throughs of grommet -C-.

Scheme 105

Note. When removing A/C unit, make sure the two coolant pipes of the heater core do not get caught and bent or damaged on plenum chamber or noise insulation mat. Observe wiring harness, individual electrical wiring connections may get damaged when pulling on harness.

Remove A/C unit -A- towards passenger side.

Scheme 106

Installation

Installation is reverse of removal, noting the following

Two technicians are needed to install the heater and A/C unit.

Note. Before installing, check all gaskets and seals on the A/C unit for damage and replace if necessary. Check securing of coolant pipes to heat exchanger.

Insert molded seal -A- (working from passenger compartment) into bulkhead -B-, make sure that reinforcement -C- (wire bracket) is positioned correctly in molded seal -A-.

Scheme 107

Ask a colleague for assistance to install the heating and A/C unit.

Have the second mechanic (working from engine compartment) guide both flanges for coolant pipes to heater core -A- and for expansion valve (to evaporator) -B- through pass-throughs of grommet -C- when inserting heating and A/C unit.

Note. When installing A/C unit, make sure the two coolant pipes of the heater core do not get caught and bent or damaged on plenum chamber or noise insulation mat. Observe wiring harness, individual electrical wiring connections may get damaged when pulling on harness.

Connect condensation water drain to connection on A/C unit and check condensation water drain for correct seating, refer to CONDENSATE DRAIN HOSE .

Reinstall removed components in reverse order of removal except driver storage compartment.

Note. When installing the instrument panel, make sure that the defrost intermediate piece its properly on A/C unit and the defrost vent does not pinch the intermediate piece. After installing the instrument panel, check the output direction and distribution of the air flow from the defroster vent to the windshield.

Connect coolant hoses properly to heater core. Observe markings

A - Supply hose from cylinder head

B - Return to the coolant pump

Connect refrigerant lines to expansion valve, refer to REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE .

Check installation position of coolant hoses to heater cores (they must not contact components which grow hot) and position and state of heat protection insulation applied to coolant hoses if necessary (not installed on all engine types).

Bleed cooling circuit, refer to [For engine(s) CBRA] General Information or refer to [For engine(s) BPY] General Information or refer to [For engine(s) CCTA, CBFA] General Information or refer to [For engine(s) CBEA] General Information .

Check coolant circuit for leaks, pay particular attention to the connection between coolant hoses and heater core, refer to LEAK DETECTION .

Check grommet -C- in bulkhead for proper seating.

Seal flange for coolant pipes to heater core -A- and for expansion valve (to evaporator) -B- at pass-through of grommet -C- with silicon adhesive sealant if necessary (to prevent water from penetrating).

Evacuate and recharge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Reinstall driver side storage compartment and remaining removed components.

If necessary, check the A/C system using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Check the air vent direction on vehicles with a manual climate control system. as depending on switch position, the flexible shaft rotates twice for one switch rotation via set of gears on heating A/C unit and on heating A/C unit controls. Refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

HEAT EXCHANGER

Special tools and workshop equipment required

1. Hose Clamps, Up to 40 mm 3093
2. Hose Clamps Up to 25 mm 3094
3. Cooling System Tester V.A.G 1274 (and corresponding adapter)
4. Compressed air gun, commercially available

Preliminary Work for Removal

Protect driver and front passenger seats using seat covers.

Switch off ignition.

Dissipate pressure in coolant circuit by opening cap at coolant expansion tank. Refer to [For engine(s) CBRA] General Information or refer to [For engine(s) BPY] General Information or refer to [For engine(s) CCTA, CBFA] General Information or refer to [For engine(s) CBEA] General Information .

Remove components which hinder access to coolant hoses to heater core in engine compartment -A- and -B-, refer to [For engine(s) CBRA] Removal and Installation or refer to [For engine(s) BPY] Removal and Installation or refer to [For engine(s) CCTA, CBFA] Removal and Installation or refer to [For engine(s) CBEA] Removal and Installation .

Note. Depending on engine and version of vehicle, it may be necessary to loosen or to remove the following components (top engine cover, pressurized air pipe to throttle valve part and depending on engine the intake manifold, etc.). Refer to [For engine(s) CBRA] Removal and Installation or refer to [For engine(s) BPY] Removal and Installation or refer to [For engine(s) CCTA, CBFA] Removal and Installation or refer to [For engine(s) CBEA] Removal and Installation . Depending on the engine (for example, on certain 2.0L diesel engines and depending on the type of exhaust system), it may be necessary to first move the plenum chamber cover or the front wall of the plenum chamber -A- in order to remove the heat shield, the refrigerant lines from the expansion valve and the coolant hoses leading to the heat exchanger. Refer to Removal and Installation . The heat shield -B- is available in different versions. On version 1, it is not necessary to remove the sheet metal nuts -A- and to disengage the heat shield -B- from the vehicle (coolant hoses may be disconnected even with the heat shield installed). On version 2, it is necessary to remove clamping washers -A- and clamp -C- and to disengage heat shield -B- from vehicle. For the sake of clarity, the illustrations show the heat shield -B- with the engine removed.

If necessary, remove the heat shield -B- from the front of the plenum chamber and the bulkhead and move it to the side (or remove it completely).

Slide a thermal protective cover -D- and -E- as far back as possible until it is possible to installed the 3093 -F- onto the coolant hoses -A- and -B-.

Mark arrangement of coolant hoses -A- and -B-.

Note. The heater core is designed for a specific coolant flow direction, therefore coolant hoses must be connected on the proper sides (coolant hose -A- supply from cylinder head, coolant hose -B- return to coolant pump). The coolant hose arrangement is the same in both vehicles without and with A/C, this illustration shows a vehicle with A/C. Bleed the coolant circuit. Refer to [For engine(s) CCTA, CBFA] General Information .

If necessary, clamp off vent hose (from upper connection -A- to coolant expansion tank).

Cover the area beneath connections for coolant hoses -A- and -B-, for example, with a paper towel.

Clamp off coolant hoses to heater core for A/C (heater) unit (e.g. using 3093) and remove them.

Connect one section of hose -A- on to upper connection.

Hold a container -B- under the lower connection -C-.

Using a compressed air gun, carefully blow coolant out of heater core (into container -B-).

Remove bolt -A- from connector flange -B- (so that coolant pipes can be moved to remove heater core).

Scheme 108

Remove storage compartment on driver side. Refer to Removal and Installation .

Remove center console. Refer to Removal and Installation .

Remove left footwell vent -A- (driver side). Refer to Removal and Installation .

Remove the bracket -B-. Refer to Removal and Installation .

In vehicles with an electric auxiliary heater (only vehicles with Diesel engine), remove Auxiliaryr Heater Heating Element -Z35- (with Auxiliary Air Heater Control Module -J604-). Refer to AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE .

Removing

Remove 4 bolts -A- and remove cover -B-.

Note. This illustration depicts the version of A/C unit with electric auxiliary heater. Cover -B- is different versions (for vehicles without or with electric auxiliary heater). If lever -C- is located in an unfavorable position so that top bolt -A- is not accessible, switch ignition on and select a different temperature setting (e.g. Hi setting on Climatronic control module / temperature rotary switch at Warm stop setting on A/C control module).

Cover carpet in area under heat exchanger with waterproof foil and absorbent paper towel.

Remove bolts -A- and remove clamps -B- from connections of coolant pipes -C- and -D- at heater core -E-.

Scheme 109

Disconnect coolant pipes -C- and -D- from heater core -E- (slide coolant pipes toward bulkhead).

Pull heater core -E- out of heating and A/C unit.

Installing

Installation is carried out in the reverse order, when doing this note the following

Check the heater core seals -A- and -B-.

Scheme 110

Note. Seal may curl up on insertion if not correctly bonded on. Cold air may flow past heat exchanger if seal is damaged or not properly fitted. Beginning with MY 2005, the corners of the heat exchanger -B- have an additional foam strip -A-. These foam strips -A- should prevent certain rattling noises which occur especially on vehicles with diesel engines. Attach these strips on all heat exchangers (e.g. self-adhesive foam strip with part number 191 819 069).

With the heater core removed, check heating and A/C unit for soiling (via heater core opening -A-).

Scheme 111

Remove any dirt or coolant still inside the A/C unit (heater) after the heat exchanger is removed.

Slide heater core into heating and A/C unit.

Remove old clamps -B- from both coolant pipes -C-.

Scheme 112

Install new (included in delivery of heater core) clamps -A- on both coolant pipes for heater core according to illustration.

Moisten new seals -A- (included in heater core delivery casing) lightly with coolant.

Insert new seals -A- into connections of heater core -D-.

Push both coolant pipes -C- into heater core connections -D-.

Check seating of seals -A- again between coolant pipes -C- and connections of heater core -D-.

Secure both coolant pipes -C- and -D- with clamps -B- on heater core.

Tighten bolts on clamps -A- to 2.5 Nm.

Check seating of both clamps -B- after tightening bolts -A-, clamps must enclose the flange on heater core and coolant pipe completely and must not touch other components.

Thread bolt -A- into connector flange -B - (while doing this make sure bolt is actually threaded into the mounting point intended for it).

Check position of grommet -C- in bulkhead for proper seating.

Seal flange for coolant pipes to heater core -A- and for expansion valve (to evaporator) -B- at pass-through of grommet -C- with silicon adhesive sealant if necessary (to prevent water from penetrating).

Connect coolant hoses properly to heater core. Observe markings

A - Supply hose from cylinder head

B - Return to the coolant pump

Reinstall all components removed in reverse order, with the exception of cover for connections on heater core and driver side storage compartment.

Check installation position of coolant hoses to heater cores (they must not contact components which grow hot) and position and state of heat protection insulation applied to coolant hoses if necessary (not installed on all engine types).

Bleed cooling circuit, refer to [For engine(s) CBRA] General Information or refer to [For engine(s) BPY] General Information or refer to [For engine(s) CCTA, CBFA] General Information or refer to [For engine(s) CBEA] General Information .

Note. When bleeding coolant circuit, take special care to ensure complete bleeding of heat exchangers. If there are still air bubbles in the heater core, it may cause the customer to complain of insufficient heating performance in winter or different air temperature from vents at same setting in regulated mode, refer to HEATING PERFORMANCE OF A/C SYSTEM, CHECKING . Depending on vehicle equipment and on engine, heat insulation has been applied to coolant hoses, these must not be damaged and must be re-applied after installing.

Check the cooling system for leaks. Pay close attention to the connections between the coolant pipes and the heat exchanger. Refer to LEAK DETECTION .

Check the cooling system for leaks

1. Bleed the coolant circuit. Refer to «[For engine(s) CBRA] General Information»(ref-496050-S22044718802012082100000) or refer to «[For engine(s) BPY] General Information»(ref-496061-S27305721662012082100000) or refer to «[For engine(s) CCTA, CBFA] General Information»(ref-496038-S09726818432012082100000) or refer to «[For engine(s) CBEA] General Information»(ref-496039-S24047860002012082100000) .
2. Carefully open coolant reservoir cap (observe safety cautions when opening the cap). Refer to «[For engine(s) CBRA] General Information»(ref-496050-S22044718802012082100000) or refer to «[For engine(s) BPY] General Information»(ref-496061-S27305721662012082100000) or refer to «[For engine(s) CCTA, CBFA] General Information»(ref-496038-S09726818432012082100000) or refer to «[For engine(s) CBEA] General Information»(ref-496039-S24047860002012082100000) .
3. Increase pressure in coolant circuit, for example, using a hand pump V.A.G 1274/.

Reinstall cover for connections on heater core, driver side storage compartment and the remaining components that were removed.

HIGH PRESSURE SENSOR

Note. Vehicles with automatically regulated A/C system the Climatronic Control Module -J255- evaluates the signal from the High Pressure Sensor -G65- and actuates the compressor via the A/C Compressor Regulator Valve -N280-. Vehicles with manually regulated A/C system the A/C Control Module -J301- evaluates the signal from high pressure sensor and actuates the compressor via the A/C compressor regulator valve. Depending on the version of the high pressure sensor, an insufficient measuring value for the pressure in the refrigerant system will be sent by the high pressure sensor at low outside temperatures (lower than 5 °C) (even though the A/C system is OK and the refrigerant circuit is properly filled). In the A/C control module or in the Climatronic control module, part number 8P0 820 043 up to index AH can register in incorrect DTC memory entry at low outside temperatures (lower than 5 °C) (DTC memory entry: high pressure sensor "lower values not met"). The outside conditions, at which the fault was store, are displayed in the measuring value block for the automatic A/C system, check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. If the fault is displayed as a sporadic fault at an outside temperature greater than 5 °C, calculated by the A/C system, and if the A/C function is OK, then clear the DTC memory (no additional steps are necessary). The cooling output cannot be checked with high pressure sensor removed. Climatronic control module / A/C control module does not switch on the A/C compressor. The refrigerant circuit remains closed, connection with valve. Checking function of high pressure sensor and signal sent, refer to HIGH PRESSURE SENSOR, CHECKING PRESSURE SIGNAL . Different component locations depending on engine, high pressure sensor in vehicles with 2.0L Diesel engine is installed not on refrigerant line from expansion valve to condenser but rather on refrigerant line from compressor to condenser. In vehicles with a 1.6L gasoline engine, the high pressure sensor may currently be removed without having to remove other components (accessible from top). After switching off the A/C compressor on this vehicle, it may take a long time until the pressure on the high pressure side (the expansion valve is cold and the pressure on the low pressure side increases quickly after switching off, the expansion valve closes and the refrigerant can flow slowly on the low pressure side.

Remove the noise insulation (currently not necessary on vehicles with a 1.6 L gasoline engine). Refer to Removal and Installation .

Disconnect connector -A- from high pressure sensor -B-.

Scheme 113

Note. Depending on the engine, remove the high pressure sensor, the ribbed belt from the generator (for example, on the 2.0L TFSI engine). Refer to [For engine(s) CBRA] Removal and Installation or refer to [For engine(s) BPY] Removal and Installation or refer to [For engine(s) CCTA, CBFA] Removal and Installation or refer to [For engine(s) CBEA] Removal and Installation .

Remove high pressure sensor -B- (tightening torque: 8 Nm).

Replace O-ring -C-, refer to REFRIGERANT CIRCUIT O-RINGS .

INSTRUMENT PANEL VENT

Special tools and workshop equipment required

1. Hook 3438

Note. Instrument panel vents -B- can only be removed and installed when control ring -A- stands in the 45° position. Control lever of vent is located only in this position so that vent can be removed and installed at instrument panel without being damaged. Instrument panel vents -B- can only be installed in a certain position, therefore note the position of the control ring -A- when installing.

Set control ring -A- of instrument panel vent -B- to be removed to 45° position

Attach the 3438 -A- to the back of the -C- instrument panel vent -B-.

Scheme 114

Carefully pull the applicable instrument panel vent -B- out of instrument panel.

INTERIOR TEMPERATURE SENSOR FAN

Note. Not installed on vehicles with manually regulated A/C system

Remove the Climatronic Control Module -J255-, refer to CLIMATRONIC CONTROL MODULE .

Remove bolts -A-.

Scheme 115

Pull Interior Temperature Sensor Fan -V42- -B- out of the Climatronic control module.

Note. When installing interior temperature sensor fan, do not press on motor -C-, hold fan firmly at housing instead.

REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR

Note. Compressor is always driven when engine is running; there is no magnetic clutch. Engine is therefore not to be started unless refrigerant circuit has been properly assembled. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. The following illustration depicts a A/C compressor for a vehicle with 4-cylinder diesel engine, the allocation may deviate slightly for vehicles with other engines, however the refrigerant lines are disconnected in the same way. Close open lines and connections on A/C compressor using suitable caps (to prevent possible penetration of dirt and moisture).

Removing

Evacuating the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT .

Remove the engine cover (depending on engine, not necessary for all engine types). Refer to ENGINE COVER WITH AIR FILTER ELEMENT .

Remove center noise insulation. Refer to Removal and Installation .

Remove the noise insulation frame, if equipped (for example, currently on the Audi A3 Cabrio). Refer to Removal and Installation .

On vehicles, where the screws on the refrigerant line connection are not accessible when the A/C compressor is installed, remove the A/C compressor from the bracket (for example, on 3.2L MPI vehicles). Refer to COMPRESSOR, REMOVING FROM BRACKET .

Remove this bracket for vehicles in which the refrigerant lines are secured by additional brackets.

Remove bolts -A- and -D-.

Scheme 116

Disconnect refrigerant lines -B- and -E-.

Installing

Installation is the reverse of removal, noting the following

Replace O-rings seals -C- and -F-, refer to REFRIGERANT CIRCUIT O-RINGS .

Check fitted pin -H- (not installed at all connections) and sleeve -J- for damage and proper seating.

Tighten bolts -A- and -D- to 25 Nm.

Note. The O-rings from the caps used on the replacement A/C compressors may not be used again. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . Make sure the O-ring seals are seated properly in the groove -G- on the respective refrigerant line. Following attachment of refrigerant pipes to compressor (and installation of compressor) check routing of pipes. They must be inserted in holders provided and not make contact with other components.

Evacuate and recharge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to A/C SYSTEM, OPERATING AFTER CHARGING .

REFRIGERANT LINES, DISCONNECTING FROM CONDENSER

Note. Condenser is available in different versions, depending on version of vehicle. Refrigerant line from condenser to evaporator is available in different versions, depending on version of vehicle. In vehicles with parking heater, line outlet from connection on condenser may be shaped differently (so that it does not contact parking heater). There are different versions of the High Pressure Sensor -G65- depending on the engine. For example, on a vehicle with a 2.0L diesel, the high pressure sensor is installed on the refrigerant line from the A/C compressor to the condenser and not on the refrigerant line from the expansion valve to the condenser.

Removing

Evacuate the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Remove the noise insulation. Refer to Removal and Installation .

Disconnect connector -A- from High Pressure Sensor -B-.

Remove bolts -A- (tightening torque 10 Nm).

Scheme 117

Disconnect refrigerant lines -B- and -C- from condenser.

Note. Seal off the lines and connections with caps to prevent dirt and moisture from getting in.

Installing

Installation is the reverse of removal, noting the following

Replace O-rings seals -D- and -E-, refer to REFRIGERANT CIRCUIT O-RINGS .

Check fitted pin -G- (not installed at all connections) and sleeve -H- for damage and proper seating.

Note. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . Check the O-rings for proper seating within the groove -F- on the refrigerant line.

Following attachment, check routing of refrigerant pipes. They must be inserted in holders provided and not make contact with other components.

Evacuate and re-charge refrigerant circuit. Refer to CHARGING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Operate the A/C system after filling the refrigerant circuit, refer to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT .

Note. Note the information regarding operating the A/C system after filling, refer to CHARGING REFRIGERANT .

REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE

Removing

Discharge refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT and refer to DRAINING REFRIGERANT CIRCUIT .

Remove the components that hinder access to the mounting bolts for refrigerant lines -A- on expansion valve.

Note. Depending on engine and version of vehicle, it may be necessary to loosen or to remove the following components (top engine cover, pressurized air pipe to throttle valve part and depending on engine the intake manifold, etc.), refer to [For engine(s) CBRA] Removal and Installation or refer to [For engine(s) BPY] Removal and Installation or refer to [For engine(s) CCTA, CBFA] Removal and Installation or refer to [For engine(s) CBEA] Removal and Installation . Depending on the engine (for example, on certain 2.0L diesel engines and depending on the exhaust system) it may be necessary to remove the plenum chamber cover and the front wall of the plenum chamber -A- in order to be able to remove the heat shield and to remove the refrigerant lines from the expansion valve and the coolant hoses from the heat exchanger, refer to Removal and Installation . The heat shield -B- is available in different versions. For version 1, sheet metal nuts -A- must be removed and heat shield -B- disengaged from vehicle. On version 2, clamping washers -A- and clamp -C- must be removed and heat shield -B- disengaged from vehicle. If heat shield -B- hinders further work because of the coolant hoses, separate heat shield -B- at locations marked with -D- (e.g. using a diagonal cutter) and remove it completely. For the sake of clarity, the illustrations show the heat shield -B- with the engine removed.

Loosen the heat shield -B- from the plenum chamber and from the bulkhead and move it to the side, or remove it completely.

Remove bolts -A- (tightening torque 10 Nm).

Disconnect refrigerant lines -B- and -C-.

Note. Seal off all line and connections on the expansion valve with caps to prevent dirt and moisture from getting in.

Installing

Installation is the reverse of removal, noting the following

Replace O-rings seals -D- and -E-, refer to REFRIGERANT CIRCUIT O-RINGS .

Check fitted pin -G- (installed in connection or in expansion valve, not installed at all connections) and sleeve -H- for damage and proper seating.

Note. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . Check the O-rings for proper seating within the groove -F- on the refrigerant line. Install refrigerant pipes such that they are not strained. Depending on vehicle equipment and on engine, heat insulation has been applied to refrigerant lines, these must not be damaged and must be re-applied after installing. Check installation position of refrigerant lines to expansion valve (they must not contact other components) and position and state of heat protection insulation applied to refrigerant lines if necessary (not installed on all engine types).

SUNLIGHT PHOTO SENSOR

Note. As a running change beginning in 11.2003, a modified Sunlight Photo Sensor -G107- and a modified Climatronic Control Module -J255-. Only sunlight photo sensor with part number 4E0 907 539 must have been/must be installed for Climatronic control module with part number without or up to index C. Only sunlight photo sensor with part number 8P0 907 539 must have been/must be installed for Climatronic control module with part number beginning with index D. If the allocation between the sunlight photo sensor and the Climatronic control module is incorrect, the Climatronic control module cannot evaluate the signal from the sunlight photo sensor and the A/C system control will malfunction. No sunlight photo sensor is installed on vehicles with manually regulated A/C system.

Switch off ignition.

Carefully pry cover -A- out of front windshield defroster vent. Refer to Removal and Installation .

Scheme 118

Carefully pry sunlight photo sensor -B- out of front windshield defroster vent.

Disconnect connector -C-.

Note. Do not interchange sunlight photo sensor -B- (4 electrical connections) with light emitting diode for central locking system and interior monitoring system -D- (2 electrical connections).

LEFT FOOTWELL VENT TEMPERATURE SENSOR

Note. The Left Footwell Vent Temperature SensorG261 is installed on vehicles with manually regulated A/C system only at beginning of production (discontinued as running change). Vehicles with manually regulated A/C system: measured value of this sensor is not evaluated by A/C Control Module -J301-, a malfunction at left footwell vent temperature sensor is not detected (it is not required for the regulation).

Removing and Installing

Remove driver side storage compartment. Refer to Removal and Installation .

Remove left footwell vent -A- (driver side). Refer to Removal and Installation .

Reach through opening between left side of A/C unit and central tube (instrument panel cross member) or support on left side of A/C unit and rotate sensor -B- into position in which connector -A- can be disconnected.

Disconnect the connector -A- (for example, using needle-nose pliers)

Scheme 119

Turn sensor -B- 90° and pull it out of A/C unit.

Check seal -C- for proper seating when installing.

Note. If sensor -B- cannot be rotated or sensor -B- is not accessible by reason of other components, remove instrument panel. Refer to Removal and Installation . This illustration depicts sensor -B- with instrument panel removed. With instrument panel installed, the sensor -B- is visible from underneath when the footwell vent is removed (part of sensor with temperature sensor is visible in air guide channel).

RIGHT FOOTWELL VENT TEMPERATURE SENSOR

Note. Not installed on vehicles with manually regulated A/C system

Remove the glove compartment. Refer to Removal and Installation .

Disconnect the connector -A-.

Scheme 120

Turn sensor -B- 90° and pull it out of A/C unit.

Check seal -C- for proper seating when installing.

LEFT VENT TEMPERATURE SENSOR

Note. Not installed on vehicles with manually regulated A/C system

Removing

Switch off ignition.

Remove the driver side storage compartment. Refer to Removal and Installation .

Disconnect harness connector -A- from temperature sensor.

Scheme 121

Turn temperature sensor -B- approximately 90°.

Remove temperature sensor -B- from air guide.

Installing

Install in reverse order of removal.

Check seal -C- for proper seating when installing.

RIGHT VENT TEMPERATURE SENSOR

Note. Not installed on vehicles with manually regulated A/C system

Removing

Switch off ignition.

Remove the glove compartment. Refer to Removal and Installation .

Disconnect harness connector -A- from temperature sensor.

Scheme 122

Turn temperature sensor -B- approximately 90°.

Remove temperature sensor -B- from air guide.

Installing

Install in reverse order of removal.

Check seal -C- for proper seating when installing.

EVAPORATOR VENT TEMPERATURE SENSOR

Remove the glove compartment and the center console. Refer to Removal and Installation .

Disconnect the connector -A-.

Scheme 123

Turn sensor -B- 90° and pull it out of A/C unit.

Check seal -C- for proper seating when installing.

FRESH AIR INTAKE DUCT TEMPERATURE SENSOR

Note. As of model year 2006, the Fresh Air Intake Duct Temperature Sensor -G89- has been gradually discontinued. On vehicles without this temperature sensor, only the Climatronic Control Module -J255- with part number as of index M is or may be installed. On vehicles without Fresh Air Intake Duct Temperature Sensor, a Climatronic control module with part no. up to index L installed enters a DTC into the DTC memory.

Removing

Remove dash panel complete with dash panel cross member. Refer to Removal and Installation .

Remove A/C unit, refer to HEATING AND A/C UNIT .

Disconnect the connector -A-.

Scheme 124

Rotate temperature sensor -B- 90° and pull it out of intake housing.

Check seal -C- for proper seating when installing.

Installing

Install all removed components in reversed order.

ATTACHMENTS - MANUALLY REGULATED A/C SYSTEM

Remove A/C unit, refer to HEATING AND A/C UNIT .

Version for vehicles with manually regulated A/C system

Scheme 125

1. Screw
2. A/C System Controls, A/C Control Module -J301- Different versions depending on vehicle equipment (with and without Heated Driver Seat Adjuster -E94- and Heated Front Passenger Seat Adjuster -E95-). Removing and installing, refer to «HEATER CONTROLS»(ref-496069-S20638973832012082100000) . Function, electrical test, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
3. A/C System Controls / Base Plate Different versions of base plate on vehicles with manually regulated A/C system and without A/C system (with heating system only). Removing and installing, refer to «HEATER CONTROLS»(ref-496069-S20638973832012082100000) .
4. Heating and A/C Unit With Evaporator (Of Manually Regulated A/C System) Different versions of heating A/C unit in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . Heating and A/C unit, disassembling and assembling, refer to «A/C UNIT»(ref-496031-S18933065322012082100000) . Disassembling and assembling evaporator housing, refer to «EVAPORATOR HOUSING»(ref-496031-S12685433762012082100000) .
5. Auxiliary Heater Heating Element -Z35- (with Auxiliary Air Heater Control Module -J604-) Only on diesel vehicles, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the auxiliary air heater heating element via the auxiliary air heater control module, refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. On diesel vehicles built from November 2006 (running change) have a 3-stage auxiliary air heater heating element which is controlled by a relay from the Engine Control Module (ECM). Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an auxiliary heater heating element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the auxiliary heater heating element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Check the auxiliary air heater control module, perform Guided Fault Finding using Vehicle Diagnosis, Testing and Information System VAS 5051. Removing and installing, refer to «AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE»(ref-496031-S23889843062012082100000)
6. Cover For Coolant Pipes And Heater Core This illustration shows version for vehicles with auxiliary heater heating element. Different versions for vehicles with or without auxiliary heater heating element (opening for auxiliary heater heating element is sealed by this cover in vehicles without auxiliary heater heating element).
7. Screw
8. Temperature Regulator Door Motor -V68- With Temperature Regulator Door Motor Position Sensor -G92- Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE / TEMPERATURE REGULATOR DOOR MOTOR»(ref-496031-S18972377132012082100000) . The name for this control motor in Guided Fault Finding and in the wiring diagram is different on vehicles with a manually and an automatically regulated A/C system, refer to refer to the appropriate SYSTEM WIRING DIAGRAMS information.. On vehicles with manually regulated A/C system, this control motor operates both temperature doors (the right and left temperature doors are connected to each other via the shaft). On vehicles with an automatically regulated A/C system, the left and right temperature doors are each actuated by one control motor.
9. Connecting Rod to Temperature Regulator Door Motor -V68- Color identification: white.
10. Left Footwell Vent Temperature Sensor -G261- This sensor is installed only at beginning of production (discontinued as running change). Measured value of this sensor is not evaluated by A/C control module, a malfunction at left footwell vent temperature sensor is not detected. Removing and installing, refer to «LEFT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S38962577942012082100000) .
11. Cover and Bracket For Recirculation Door Motor -V113- Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(ref-496069-S25088012372012082100000) . After installing bracket, check control motor, if it is not installed free of play, eliminate play if necessary with some foam applied to inside of bracket mounting points, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(ref-496069-S25088012372012082100000) .
12. Recirculation Door Motor -V113- Different versions of recirculation door motor in vehicles with manually and automatically regulated A/C system. Checking function using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(ref-496069-S25088012372012082100000) .
13. Foam Seal For sealing air intake housing of heating A/C unit to vehicle.
14. Intake Housing With Fresh/Recirculating Air Door Do not disassemble. Different versions in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «AIR INTAKE HOUSING»(ref-496031-S31791968262012082100000) .
15. Fresh Air Blower -V2- Different versions in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM»(ref-496069-S28855578172012082100000) .
16. Fresh Air Blower Series Resistor With Fuse -N24- Removing and installing, refer to «FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM»(ref-496069-S25399057542012082100000) .
17. Evaporator Vent Temperature Sensor -G263- Removing and installing, refer to «EVAPORATOR VENT TEMPERATURE SENSOR»(ref-496031-S28737448952012082100000) .
18. Flexible Shaft To gear mechanism / curved washer for activation of air distribution doors. Removing and installing, refer to «AIR DISTRIBUTION FLEXIBLE SHAFT»(ref-496069-S22647833952012082100000) .
19. Wiring Harness Bracket
20. Cable Ties
21. Insulation Mat
22. Screw Clips
23. Wiring Harness Of Manually Regulated A/C System Different versions (e.g. with or without connection to Auxiliary Air Heater Control Module). Mark the allocation before disconnecting the connectors (danger of interchange, connectors of same shape for different motors and temperature sensor). Secure wiring harness to mounting points provided on housing (using cable ties, or on mounts) so that it does not come into contact with moving components.

ATTACHMENTS - AUTOMATICALLY REGULATED A/C SYSTEM

Remove A/C unit, refer to HEATING AND A/C UNIT .

Version for vehicles with automatically regulated A/C system

Scheme 126

1. Wiring Harness Of Automatically Regulated A/C System Different versions (e.g. with or without connection to Auxiliary Air Heater Control Module -J604-, with and without Fresh Air Intake Duct Temperature Sensor -G89-, with and without connection to Air Flow Door Motor -V71-, etc.). Mark the allocation before disconnecting the connectors (to prevent confusing connectors of same shape for different motors and temperature sensor). Secure wiring harness to mounting points provided on housing (using cable ties, or on mounts) so that it does not come into contact with moving components. NOTE: From model year 2006, the Fresh Air Intake Duct Temperature Sensor -G89- has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic Control Module -J255- with part no. as of index M is or may be installed. On vehicles without fresh air intake duct temperature sensor, a Climatronic control module with part number up to index L installed enters a DTC into the DTC memory. Up to the end of model year 2007, the air flow door (fresh air door) was moved by Air Flow Door Motor -V71-. From the end of model year 2007, the air flow door motor is being discontinued as a running change. On vehicles without the air flow door motor the air flow door is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) . Therefore note the correct allocation of the Climatronic control module. If the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction.
2. Heating A/C Unit With Evaporator (Of Automatically Regulated A/C System) Different versions of heating A/C unit in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . Heating and A/C unit, disassembling and assembling, refer to «A/C UNIT»(ref-496031-S18933065322012082100000) . Disassembling and assembling evaporator housing, refer to «EVAPORATOR HOUSING»(ref-496031-S12685433762012082100000) .
3. Auxiliary Heater Heating Element -Z35- with Auxiliary Air Heater Control Module -J604- Only on diesel vehicles. The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the auxiliary heater heating element is via the auxiliary air heater control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function. On diesel vehicles built from November 2006 (running change) have a 3-stage auxiliary heater heating element which is controlled by a relay from the Engine Control Module (ECM). Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and refer to the appropriate SYSTEM WIRING DIAGRAMS information. At this time, an auxiliary heater heating element is also installed in vehicles with Diesel engine and parking heater as optional equipment. At a later point in time (not yet finalized), the auxiliary heater heating element will be discontinued, then the parking heater undertakes the function of the auxiliary heater. Check the auxiliary air heater control module, perform Guided Fault Finding using Vehicle Diagnosis, Testing and Information System VAS 5051. Removing and installing, refer to «AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE»(ref-496031-S23889843062012082100000) .
4. Cover For Coolant Pipes And Heater Core This illustration shows version for vehicles with Auxiliary Heater Heating Element -Z35-. Different versions for vehicles with or without auxiliary heater heating element (opening for auxiliary heater heating element is sealed by this cover in vehicles without auxiliary heater heating element).
5. Screw
6. Central Air Door Motor -V70- With Central Door Motor Position Sensor -G112-. Removing and installing, refer to «CENTRAL AIR DOOR MOTOR»(ref-496031-S11886634592012082100000) .
7. Left Temperature Door Motor -V158- With Left Temperature Door Potentiometer/Actuator -G220-. Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE / TEMPERATURE REGULATOR DOOR MOTOR»(ref-496031-S18972377132012082100000) .
8. Connecting Rod to Left Temperature Door Motor -V158- Color identification: white (longer than connecting rod to Right Temperature Door Motor -V159-).
9. Defroster Door Motor -V107- With Defroster Door Motor Position Sensor -G135-. Lever color identification: blue. Removing and installing, refer to «DEFROSTER DOOR MOTOR»(ref-496031-S20716524382012082100000) . NOTE: This motor is fastened on the right on air distributor housing in vehicles with right-side steering.
10. Connecting Rod to Defroster door motor -V107- Color identification: blue.
11. Left Footwell Vent Temperature Sensor -G261- Removing and installing, refer to «LEFT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S38962577942012082100000) .
12. Right Footwell Vent Temperature Sensor -G262- Removing and installing, refer to «RIGHT FOOTWELL VENT TEMPERATURE SENSOR»(ref-496031-S24526980612012082100000) .
13. Cover and Bracket for Air Flow Door Motor -V71- and Recirculation Door Motor -V113- Removing and installing (refer to Recirculation Door Motor -V113-, removing) «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . After installing, check both control motors which must be held in position by this bracket, if they are not installed free of play, use some foam to correct play if necessary, attaching it to inside of mounting points of bracket, refer to «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . Cover is installed only on version with Air Flow Door Motor -V71- (Recirculation Door Motor -V113- is bolted firmly on intake housing on version without air flow door motor), refer to «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . Up to the end of model year 2007, the back pressure door was moved by Back Pressure Door Motor -V71-. From the end of model year 2007, the air flow door motor is being discontinued as a running change. On vehicles without the air flow door motor the air flow door is actuated via a curved washer and lever of the recirculation door motor, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) .
14. Recirculation Door Motor -V113- With Recirculation Door Motor Position Sensor -G143-. Removing and installing, refer to «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . Different versions depending on version of intake housing.
15. Airflow Door Motor -V71- With Back Pressure Door Motor Position Sensor -G113-. Removing and installing, refer to «AIR FLOW DOOR MOTOR AND POTENTIOMETER»(ref-496031-S24692709702012082100000) . Only present on vehicles that were manufactured up to end of model year 2007, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) .
16. Foam Seal For sealing air intake housing of heating A/C unit to vehicle.
17. Intake Housing With Recirculating Air Back Pressure Door (Fresh Air Door) Do not disassemble. Removing and installing, refer to «AIR INTAKE HOUSING»(ref-496031-S31791968262012082100000) . Different versions on vehicles with and without Fresh Air Intake Duct Temperature Sensor -G89- Different versions (e.g. with and without fresh air intake duct temperature sensor, with and without Air Flow Door Motor -V71-, etc.). Up to the end of model year 2007, the back pressure door was moved by Back Pressure Door Motor -V71-. From the end of model year 2007, the air flow door motor is being discontinued as a running change. On vehicles without the air flow door motor the air flow door is actuated via a curved washer and lever of the Recirculation Door Motor -V113-, refer to «RECIRCULATION DOOR MOTOR»(ref-496031-S28868787432012082100000) .
18. Fresh Air Intake Duct Temperature Sensor -G89- Removing and installing, refer to «FRESH AIR INTAKE DUCT TEMPERATURE SENSOR»(ref-496031-S34189917812012082100000) . NOTE: From model year 2006, the fresh air intake duct temperature sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic Control Module -J255- with part no. as of index M is or may be installed. On vehicles without fresh air intake duct temperature sensor, a Climatronic control module with part number up to index L installed enters a DTC into the DTC memory.
19. Fresh Air Blower Control Module -J126- and Fresh Air Blower -V2- Different versions in vehicles with manually and automatically regulated A/C system. Removing and installing, refer to «FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM»(ref-496031-S01188964712012082100000) . Different versions, as of model year 2007 the Fresh Air Blower Control Module -J126- and Fresh Air Blower -V2- can each be replaced separately (running change in production), refer to «FRESH AIR BLOWER AND CONTROL MODULE, AUTOMATICALLY REGULATED A/C SYSTEM»(ref-496031-S01188964712012082100000) . Fresh Air Blower Control Module is installed in Fresh Air Blower. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
20. Insulation Mat
21. Screw Clips
22. Right Temperature Door Motor -V159- With Right Temperature Door Potentiometer/Actuator -G221-. Lever color identification: black. Removing and installing, refer to «RIGHT TEMPERATURE DOOR MOTOR»(ref-496031-S09255170142012082100000) .
23. Connecting Rod to Right Temperature Door Motor -V159- Color identification: black (shorter than connecting rod to Left Temperature Door Motor -V158-).
24. Evaporator Vent Temperature Sensor -G263- Removing and installing, refer to «EVAPORATOR VENT TEMPERATURE SENSOR»(ref-496031-S28737448952012082100000) .
25. Cable Ties
26. Wiring Harness Bracket

A/C UNIT

Remove A/C unit, refer to HEATING AND A/C UNIT .

Remove attachments from heating and A/C unit, refer to ATTACHMENTS - MANUALLY REGULATED A/C SYSTEM (version with manual regulation).

Remove attachments from heating and A/C unit, refer to ATTACHMENTS - AUTOMATICALLY REGULATED A/C SYSTEM (version with automatic regulation).

Scheme 127

1. Air Distribution Housing For A/C System Do not disassemble further. On vehicles without an Auxiliary Heater Heating Element -Z35- the opening for the auxiliary air heater heating element is covered by the cover for the heat exchanger. If necessary, coat bearing areas and guides of temperature doors thinly with grease (e.g. with G 052 745 A3) Different versions in vehicles with manually and automatically regulated A/C system. A step-up gear with curved washer for actuating air distribution doors is installed on the air distribution housing for vehicles with manually regulated A/C system. Do not remove this step-up gear as the adjustment cannot be reestablished. Beginning November 2007, an air distribution housing (for heating or A/C) with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed. On vehicles with out A/C (just heating) or with a manual A/C system, the change to this door has no influence on the controls (the door is controlled only by adjusting the heating or A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(ref-496031-S04262121652012082100000) . NOTE: On vehicles with manually regulated A/C system, the air distribution doors are moved manually via a flexible shaft. On vehicles with automatically regulated A/C system, air distribution doors are actuated by different control motors. On vehicles with manually regulated A/C system, the right and left temperature doors are connected to each other via the shaft and are operated by a control motor. On vehicles with an automatically regulated A/C system, the left and right temperature doors are each actuated by one control motor. The change to the door has no influence on the A/C controls on vehicles with manual A/C (without automatic A/C) (the door is controlled only when the manual A/C is adjusted). On vehicles with an automatic A/C, the Climatronic Control Module -J255- was already changed at the end of MY 2007. The Climatronic control module, part number 8P0 820 043 beginning with index AE can be entered, via the "adaptation", and the version of the door in the air outlet to the defroster vents in the instrument and number of control motors on the A/C unit (with and without Back Pressure Door Motor -V71-) (Climatronic control module). Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
2. Screw
3. Air Guide Channel To Left Footwell Vent A/C system version (with temperature sensor mount). NOTE: Vehicles with manually regulated A/C system: temperature sensor will be discontinued at a later point in time (date not yet finalized), the mount is sealed on vehicles without temperature sensor.
4. Heat Exchanger For Heater Unit Removing and installing, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
5. Sealing Ring Replace. Coat thinly with coolant and insert on proper side, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
6. Clip Replace. Ensure it is seated correctly. Removing and installing, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
7. Screw Tightening specification 2.5 Nm
8. Coolant Pipes Disconnecting and connecting from heater core, refer to «HEAT EXCHANGER»(ref-496031-S34559571622012082100000) .
9. Foam Spacer Installed between grommet and A/C unit.
10. Grommet Insert before installing A/C unit into vehicle bulkhead, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) . Installing, refer to «HEATING AND A/C UNIT»(ref-496031-S01239610572012082100000) .
11. O-ring Replacing, refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) . Allocation.
12. O-ring Replacing, refer to «REFRIGERANT CIRCUIT O-RINGS»(ref-496031-S25419497892012082100000) . Allocation.
13. Expansion Valve Refrigerant lines, disconnecting and reconnecting, refer to «REFRIGERANT LINES, DISCONNECTING FROM EXPANSION VALVE»(ref-496031-S08812543432012082100000) . Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) . NOTE: After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.
14. Screw Tightening specification 10 Nm. Removing and installing, refer to «EXPANSION VALVE»(ref-496031-S18701646112012082100000) .
15. Evaporator Housing Disassembling and assembling, refer to «EVAPORATOR HOUSING»(ref-496031-S12685433762012082100000) .
16. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(ref-496031-S36991706242012082100000) . Follow the replacement intervals, refer to «Maintenance, Diagnosis»(ref-496015-S28841274602012082100000) . With activated charcoal insert, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(ref-496031-S38707390862012082100000) .
17. Cover For Dust And Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(ref-496031-S36991706242012082100000) .
18. Air Guide Channel To Right Footwell Vent Different versions on vehicles with manually regulated A/C system (without temperature sensor mount) and on vehicles with automatically regulated A/C system (with temperature sensor mount).
19. Plug Installed only in vehicles without air duct to vent in rear center console (introduction of a vent in center console not yet finalized).

EVAPORATOR HOUSING

Remove attachments from heating A/C unit, refer to ATTACHMENTS - MANUALLY REGULATED A/C SYSTEM .

Remove attachments from heating A/C unit, refer to ATTACHMENTS - AUTOMATICALLY REGULATED A/C SYSTEM (version with automatic regulation).

Remove evaporator housing from A/C unit. Refer to A/C UNIT .

Scheme 128

1. Lower Section Of Evaporator Housing
2. Evaporator Check insulation, it must be completely present, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) . Removing and installing, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) .
3. Clip
4. Upper Section Of Evaporator Housing
5. Screw
6. Seal / Insulation Heat insulation for expansion valve. Removing and installing, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) .
7. Bracket Removing and installing, refer to «EVAPORATOR»(ref-496031-S28030570142012082100000) .