A4 Mk3
| 1 - | Heated rear window -Z1- |
| q | The request for rear window heating is transmitted from the air conditioner operating and display unit, Climatronic control unit -J255- via the data bus to the convenience system central control unit -J393-. The heated rear window -Z1- is actuated by way of the convenience system central control unit -J393- → Electrical system and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. |
| q | Notes on operation of heated rear window → Chapter |
| q | Removing and installing rear window → General body repairs, exterior; Rep. gr.64. |
| 2 - | Convenience system central control unit -J393- |
| q | The heated rear window -Z1- is actuated by way of the convenience system central control unit -J393- → Electrical system and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. |
| q | Removal/installation and checking → Electrical system and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 |
| 3 - | Label |
| q | Indicates type of refrigerant and specified capacity → Air conditioner with refrigerant R134a |
| 4 - | Plenum chamber water drains |
| q | One water drain each is fitted on the left and right in the plenum chamber. |
| q | Removing and installing, checking and cleaning → Chapter. |
| 5 - | Coolant shut-off valve |
| q | Depending on the engine, the shut-off valve is fitted in the supply or in the coolant return from the engine to the heat exchanger of the air conditioning unit. |
| – | At present, the shut-off valve is only fitted on vehicles with a 4 or 6-cyl. petrol engine. If vehicles with these engines are equipped with an auxiliary heater as optional extra, no shut-off valve is fitted (this function is assumed by the heater coolant shut-off valve -N279- fitted on vehicles with auxiliary heater → Auxiliary heater; Rep. gr.82). |
| – | The shut-off valve is vacuum-actuated by way of the Climatronic coolant shut-off valve -N422-. |
| q | For arrangement of the coolant shut-off valve and the Climatronic coolant shut-off valve -N422- on the engine or in the plenum chamber, refer to → Chapter |
| 6 - | Climatronic coolant shut-off valve -N422- |
| q | There are different Climatronic coolant shut-off valve -N422- fitting locations and designs. The valve may be fitted in the engine compartment or in the plenum chamber depending on the engine and vehicle model → Chapter. |
| – | At present, the Climatronic coolant shut-off valve -N422- is only fitted on vehicles with a 4 or 6-cyl. engine. If vehicles with these engines are equipped with an auxiliary heater as optional extra, no -N422- is fitted (this function is assumed by the heater coolant shut-off valve -N279- fitted on vehicles with auxiliary heater → Auxiliary heater; Rep. gr.82). |
| q | Actuation and operation → Chapter |
| q | For arrangement of the coolant shut-off valve and the Climatronic coolant shut-off valve -N422- in the vehicle, refer to → Chapter |
| 7 - | Ambient temperature sensor -G17- |
| q | The measured value of the ambient temperature sensor -G17- is evaluated by the onboard supply control unit -J519- and transmitted by way of the data bus to the air conditioner operating and display unit, Climatronic control unit -J255- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. |
| q | Procedure in the event of problems with an excessively high measured value for -G17- → Chapter |
| q | Removing and installing → Chapter |
| 8 - | Radiator fan -V7- and radiator fan 2 -V177- |
| q | Different versions of the radiator fan -V7- and radiator fan 2 -V177- are fitted depending on the vehicle equipment. → Electronic parts catalogue |
| q | The request for activation of the radiator fan(s) -V7- is transmitted by the air conditioner operating and display unit, Climatronic control unit -J255- by way of the data bus to the engine control unit. The engine control unit then actuates the fan(s) (radiator fan -V7- and radiator fan 2 -V177-) either directly or by way of the radiator fan control unit -J293- → Current flow diagrams, Electrical fault finding and Fitting locations and → Engine, mechanics; Rep. gr.19. |
| q | Checking actuation of the radiator fans by the air conditioner operating and display unit, Climatronic control unit -J255- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 |
| q | The corresponding engine control unit switches e.g. the radiator fan -V7- and the radiator fan 2 -V177- (directly or via the radiator fan control unit -J293-) infinitely to the desired output (depending on the engine type). → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Current flow diagrams, Electrical fault finding and Fitting locations |
| 9 - | Air quality sensor -G238- / humidity sender in fresh air intake duct -G657- |
| q | Different version → Electronic parts catalogue |
Note| t | Different versions are fitted depending on the vehicle production period and the type of air conditioner („Basic“ or „Deluxe“). Until gradual conversion of the vehicle design as of Model Year 2012, air conditioners of the „Basic“ type were not fitted with a -G657- / -G238-. After this conversion, a -G657- with no -G238- (black housing) will be fitted. Until gradual conversion of the vehicle design as of Model Year 2012, the „Deluxe“ version was fitted with a -G238- with no -G657-. After this conversion, a -G657- with a -G238- (brown housing) will be fitted. |
| t | The air quality sensor -G238- without -G657- is only fitted on vehicles with an air conditioner of the „Deluxe“ type (as of start of production until conversion) → Chapter → Electronic parts catalogue. |
| t | As of Model Year 2012, the design of the vehicles is being gradually converted, starting with the Audi A4 and Audi A5 → Chapter. On vehicles manufactured prior to conversion, air conditioners of the „Deluxe“ type are fitted with a -G238- (not fitted on „Basic“ version). On vehicles manufactured as of this conversion (and on the Audi Q5 Hybrid), the „Basic“ type is fitted with a -G657- and the „Deluxe“ type is fitted with a -G657- with -G238-. |
| q | Operation → Chapter |
| q | Checking → Chapter |
| q | Removing and installing → Chapter |
| q | The measured value of -G238- / -G657- is evaluated by the onboard supply control unit -J519- and transmitted to the operating and display unit, Climatronic control unit -J255- via the data bus. The operating and display unit, Climatronic control unit -J255- switches, on request, to air recirculation mode for example if there is no shut-off criterion → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. |
| 10 - | Fresh air intake with intake grille |
| q | Check the scuttle panel trim with the cover for the fresh air intake for proper installation and damage. Check the seals between the cover for the fresh air intake, the windscreen cross-member and the scuttle panel trim for damage and proper attachment. These seals stop water running between the windscreen cross-member and the scuttle panel trim into the intake housing of the air conditioning unit → General body repairs, exterior; Rep. gr.50. |
| q | Removing and installing → Chapter and → General body repairs, exterior; Rep. gr.50 |
| q | Check the intake grille for proper attachment. The intake grille stops foreign matter (e.g. leaves) ingressing into the intake housing of the air conditioning unit. |
| q | Depending on the version, a filter designed to stop the fresh air blower drawing in dust and sand may be fitted instead of the intake grille for certain countries with a high dust level in the ambient air (e.g. for China) → Electronic parts catalogue. |
| q | Removing and installing → Chapter |
Note| An additional cover with drip rail may be fitted at the fresh air intake housing depending on the vehicle model and the type of plenum chamber cover fitted → Chapter |
| 11 - | Forced air extractor |
| q | One forced air extractor each is fitted on the left and right beneath the rear bumper. |
| q | The sealing lips of the vent frame must move freely and close automatically. |
| q | To ensure proper functioning of the passenger compartment ventilation, the air ducts must not be blocked by the luggage compartment lining. |
| q | Checking → Chapter |
