Air Conditioning: Overview Audi A3 8P facelift

AIR RECIRCULATION DOOR MOTOR AND FRESH/AIR RECIRCULATION DOOR OPERATION

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

Note. The Air Recirculation Door Motor -V113- does not have a potentiometer, 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. The A/C control module detects via the current strength, which flows via the control motor, that is has reached its end position. The air 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 the A/C control module. Fresh/recirculating air button -F- is installed in the A/C control module. On vehicles with automatic climate control system, the air recirculation door motor is actuated via the basic setting function. The function of the Recirculation Door Motor Position Sensor -G143- is monitored by the Climatronic Control Module -J255- control motor. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". With the A/C system switched off, recirculating air mode may result in windows fogging up (moisture in air increases in passenger compartment and then condenses on windows, there is no air dehumidification by the cold A/C system evaporator). 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. In the event the air distribution rotary switch -B- is located in the air to front windshield position -D- and recirculating air mode was switched on by pressing fresh/recirculating air mode button -F- in this position of the rotary switch, recirculating air mode is to be switched off by pressing fresh/recirculating air mode button -F- so that fogged windows are defogged as rapidly as possible. A/C control module switches e.g. automatically to fresh air mode after rotary switch is set to this position (and LED lamp in button -F- goes out). Check function of fresh/recirculating air button -F- and activation of air recirculation door motor, refer to AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION .

1. Recirculation Door Motor, checking function, refer to «AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION»(ref-496031-S05471918502012082100000) .
2. Electronics in A/C control module and of air recirculation door motor, checking function, refer to «A/C CONTROL MODULE AND AIR RECIRCULATION DOOR MOTOR, CHECKING FUNCTION»(ref-496031-S14900031092012082100000) .

Scheme 1

1. Beginning November 2007, an air distribution housing (for heating or A/C) with a door -A- (in the air outlet to the defroster vents in the instrument panel) without a side cut-out -C- 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).
2. Beginning November 2007, an air distribution housing for automatic A/C with a door -A- (in the air outlet to the defroster vents in the instrument panel) without a side cut-out -C- is gradually being installed. -C- The Climatronic Control Module -J255- was already changed prior to the introduction of the door without the side cut-out with the discontinuation of the Air Flow Door Motor -V71- in June 2007.
3. Climatronic control module, part number 8P0 820 043 through index AD, may be installed only on vehicles with an A/C air distribution housing having a door in the air vent to the defroster with a side cut-out -B- and with an air flow door motor.
4. The Climatronic control module, part number 8P0 820 043 from index AE can be entered by the "adaptation" function depending on the version of the door -A- (in the air outlet to the defrost outlets in the instrument panel) and the number of control motors on the A/C (with or without air flow door motor) (adapt Climatronic control module) using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
5. If the Climatronic control module, part number 8P0 820 043 beginning with index AE (running change in production beginning in June 2007) with a door -A- (in the air vent for the defroster) having a side cut-out, is installed in a vehicle with an air distribution housing for the automatic A/C system with a door -B-, then check the adaptation and correct it if necessary. The door must be opened further by the heater controls because of the cut-out -B-. Adapt the Climatronic control module using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Scheme 2

1. Complete Evaporator Housing
2. Air Flow Door (Fresh Air Door) Shown in open position. Installed only on vehicles with automatically regulated A/C system. Up to the end of model year 2007, the back pressure door was moved by Back Pressure Door Motor -V71-. As of the end of model year 2007, the back pressure door motor has been discontinued as a running change. On vehicles without Air Flow Door Motor -V71-, the air flow door is operated via a curved washer and lever by 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.
3. Recirculated Air Door Shown in closed position. Vehicles with automatically regulated A/C system. A fresh/recirculated air door is installed on vehicles with manually regulated A/C system, refer to «AIR GUIDE CHANNEL OVERVIEW»(ref-496069-S32532538362012082100000) .
4. Fresh Air Blower -V2- With Fresh Air Blower Control Module -J126- (only installed on vehicles with automatically regulated A/C system).
5. Dust and Pollen Filter Follow the replacement intervals, refer to «Maintenance, Diagnosis»(ref-496015-S28841274602012082100000) .
6. Evaporator In vehicles without A/C system (with heater only), a foam core piece is installed for noise insulation instead of evaporator.
7. Lower Section Of Evaporator Housing (With Installed Components)
8. Air Outlet To Air Distribution Housing
9. Air Distribution Housing 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 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) using (Climatronic control module) Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

REFRIGERANT CIRCUIT COMPONENT OVERVIEW

Note. Repair work on refrigerant circuit, refer to REFRIGERANT CIRCUIT, SERVICING . All work or components marked with 1) can be repaired, replaced or performed in any workshop (work that does not pertain to refrigerant circuit). All refrigerant circuit components not marked with 1) as well as all refrigerant hoses and refrigerant lines can only be serviced or replaced in a workshop equipped with the necessary tools and in which the work procedures are performed by qualified personnel (refrigerant circuit must be discharged), refer to DESCRIPTION AND OPERATION and refer to REMOVAL AND INSTALLATION . The Guided Fault Finding functions (Checking the DTC memory, output Diagnostic Test Mode (DTM), Basic Setting Coding, Reading Measuring Value block and Adaptation) wiring and component test of the A/C system components are not described. Perform electrical testing via "Guided Fault Finding" function, here can also be found notes on the functions which should be tested using Vehicle Diagnosis, Testing and Information System VAS 5051. Temperature-dependent resistance values of the various temperature sensors are stored in one table, this can be called up via the "Guided Fault Finding" function using Vehicle Diagnosis, Testing and Information System VAS 5051.

HD = High-pressure end

ND = Low-pressure end

1. A/C Compressor Regulator Valve -N280- Checking activation and function, refer to «A/C COMPRESSOR REGULATOR VALVE, CHECKING SWITCH-ON SIGNAL»(ref-496031-S22107883002012082100000) 1) .
2. A/C Compressor A/C compressor from bracket, removing and installing, refer to «COMPRESSOR, REMOVING FROM BRACKET»(ref-496031-S01673880982012082100000) 1) . When installing refrigerant lines/hoses and pertaining bracket, make sure there is a sufficient gap between belt, bracket and belt pulley. 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) . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on the A/C compressor and the exact part number. 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. NOTE: Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo.
3. Belt Pulley Replace 1) , refer to «A/C COMPRESSOR AND PULLEY»(ref-496031-S28022874062012082100000) . Ribbed belt, removing and installing, refer to 1) : «RIBBED BELT»(ref-496100-S16261009972012082100000) . Ribbed belt allocation, 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). Depending on compressor type, different belt pulleys are installed on compressor, refer to «A/C COMPRESSOR AND PULLEY»(ref-496031-S28022874062012082100000) . The Delphi A/C compressor belt pulley cannot be removed separately.
4. Oil Drain Plug
5. Pressure Relief Valve
6. Connection With Valve Different component locations depending on engine, item 6a shows component location e.g. in vehicles with 2.0 L Diesel engine.
7. High Pressure Sensor -G65- 1) 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 e.g. in vehicles with 2.0 L Diesel engine.
8. Condenser In vehicles with rough terrain equipment, an additional stone deflector may be installed in lower area.
9. Fluid Reservoir Fluid reservoir is mounted directly on the condenser.
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 to measure pressures, to discharge and recharge the refrigerant circuit, 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. 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
13. Evaporator
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 to measure pressures and to discharge the refrigerant circuit, 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. 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 not installed on the 2.0L diesel engine).
17. Connection In Refrigerant Line Not installed on all vehicles (currently, for example, installed on 6-cylinder vehicles).