Heating, Ventilation Audi A3 8P рестайлинг

SAFETY PRECAUTIONS FOR VEHICLES WITH START/STOP SYSTEM

INSTRUMENT PANEL VENTS AND AIR DUCTS

Note. 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 . Design of heating and A/C unit as well as various work procedures to remove specific components are the same for vehicles with heater or A/C system. Air ducts inside the vehicle, refer to INSTRUMENT PANEL OVERVIEW . Air intake apparatus, air outlet and air guide in heater, refer to AIR DISTRIBUTION HOUSING OVERVIEW . Contact corrosion. Refer to CONTACT CORROSION . Component locations of individual components, refer to HVAC OVERVIEW .

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, 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 also 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.

HEATER CONTROL MODULE FUNCTIONS

Note. A/C system functions (A/C Control Module -J301-), refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

1. Rear Window Defogger -Z1- activation, refer to «HEATED REAR WINDOW»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heated-rear-window-z1) .
2. Function of air recirculation button and activation of Fresh/Recirculation Air Door Motor -V154- refer to «AIR RECIRCULATION BUTTON AND FRESH/RECIRCULATION AIR DOOR MOTOR CONTROL»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation) .
3. Testing of seat heater (optional equipment) activation, refer to «TESTING SEAT HEATER ACTIVATION»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__seat-heater-activation-testing) .
4. Activation of Engine Control Module -ECM- (in vehicles with gasoline direct fuel injection engine FSI and/or with an engine with diagram-mapped cooling, refer to «TESTING ENGINE CONTROL MODULE (ECM) ACTIVATION»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__engine-control-module-ecm-activation-testing) .
5. Auxiliary heater activation (vehicles without A/C), refer to «TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__auxiliary-air-heater-heating-element) .
6. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. The Heater Control Module -J65- has no affect on the Start/Stop function on vehicles with only a heater (no A/C). 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. The A/C control module does not limit the Stop function when the cooling mode is on. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
7. There is no additional coolant pump for the Start/Stop System installed on vehicles with Start/Stop System. An electric coolant pump may be present depending on the vehicle engine, which is controlled by an engine control module. Refer to «[For engine(s) CBRA] AFTER-RUN COOLANT PUMP»(/audi/a3/8p-2004-2008/remont/cooling-fan/#32l-cooling-system-engine-codes-bub-cbra__after-run-coolant-pump) or refer to «[For engine(s) BPY] AFTER-RUN COOLANT PUMP OVERVIEW»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy) or refer to «[For engine(s) CCTA, CBFA] AFTER-RUN COOLANT PUMP -V51»(ref-496038-S10323174952012082100000) and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
8. 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.

HEATER CONTROLS

Heater Control Module -J65- on vehicles without A/C system

A/C control module -J301- on vehicles with manual A/C

Note. The Heater Control Module -J65- -A- (A/C Control Module -J301-) is available in different versions (with and without Heated Driver Seat Adjuster -E94- and Heated Front Passenger Seat Adjuster -E95- -C-, with different surfaces and rotary switches). 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. The base plate -B- is different between vehicles without A/C (with a control for Bowden cable to temperature door) and with manual A/C (without a Bowden cable control, the temperature door is moved by a control motor). Since there is no Bowden cable to the temperature door present on vehicles with manual climate control system, the temperature control rotary switch can be twisted somewhat more easily than the air distribution rotary switch. Heater controls (A/C system controls) consist of heater control module -A- (A/C control module) and a base plate -B-. A step-up gear for operating the flexible shaft (for air distribution) is installed in base plate -B-. The flexible shaft rotates 2 times for one switch rotation via the step-up gear on heater / on heating and A/C unit and on base plate of heater / A/C system controls. Refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE . The heater controls (heater control module) -A- do not have a DTC memory (Guided Fault Finding is not possible) and are not connected to the CAN-Bus system. The A/C controls (A/C control module) -A- have a DTC memory (Guided Fault Finding is possible) and is connected to the data bus. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Both rotary switches -A- and -B- in certain versions have only be inserted and can be pulled off. Only if they can be pulled off can they be replaced individually. If both rotary switches -A- and -B- are fixed on (and cannot be pulled off), individual components of heater control module (of A/C control module) as well as lamps (LEDs = Light Emitting Diodes) for illuminating buttons and rotary switches cannot be replaced individually. Illumination of rotary switches and buttons of heater controls (A/C system controls) occurs via terminals 58s and 58d. On vehicles without A/C system, these two terminals are connected directly to heater control module, refer to appropriate SYSTEM WIRING DIAGRAM. On vehicles with a manual A/C, the switch condition and the voltage of both terminals is checked by the databus system from the A/C control module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". Function indicator lamp in fresh/recirculating air button -F- of heater controls is supplied with voltage via terminals 58d. 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".

1. Heater control functions (heater control module), refer to «HEATER CONTROL MODULE»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-control-module-functions) .

AIR DISTRIBUTION HOUSING OVERVIEW

Note. To illustrate air guide in the air distribution housing, it is shown in the form of sectional views A - A and B - B. On the heater, the various doors for air distribution are moved together via a flexible shaft and various levers and two curved washers.

Scheme 129

1. Air Distribution Housing
2. Left Temperature Door (Driver Side) Shown in center position. Both left and right temperature doors are moved together at heater (separate adjustment for driver and front passenger not possible).
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) Shown in center position. Both left and right temperature doors are moved together at heater (separate adjustment for driver and front passenger not possible).
6. Left Footwell Door (Driver Side) Shown in closed position.
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-) 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 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 Engine Control Module (ECM), refer to «TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__auxiliary-air-heater-heating-element) and appropriate SYSTEM WIRING DIAGRAM. 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. Currently diesel and gasoline vehicles are not equipped with an auxiliary heater; the parking heater is not controlled like an auxiliary heater. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".
10. Heater Core For Heater Unit
11. Air Outlet From Air Guide Channel
12. Right Temperature Door (Front Passenger Side) Shown in center position.
13. Right Footwell Door (Front Passenger Side) Shown in closed position.
14. Defroster Door Shown in closed position. NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .
15. Air Distribution Housing Sectioned Above Line B - B
16. Central Door Center Shown in open position.
17. Door In Air Guide Channel To Air Guide To Vent In Center Console At Rear This door is operated via an actuating arm installed at center 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 center console has not yet been finalized.

Scheme 130

1. Complete Air Guide Channel
2. Fresh/Recirculating Air Door Opening for air intake from plenum chamber (fresh air).
3. Opening For Air Intake In Recirculating Air Mode
4. Fresh Air Blower -V2
5. Dust and Pollen Filter Follow the replacement intervals, refer to «Maintenance, Diagnosis»(/audi/a3/8p-2004-2008/remont/procedures/#how-to-diagnosis-the-maintenance-maintenance-intervals) . As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element).
6. Noise Insulation 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 Air Guide Channel (With Installed Components)
8. Fresh Air Blower Series Resistor With Fuse -N24- Removing and installing, refer to «FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__fresh-air-blower-series-resistor-with) .
9. Air Outlet To Air Distribution Housing
10. Air Distribution Housing NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .

Scheme 131

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»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
2. Defroster Vent For front windshield. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) If the Intermediate piece between heater and air duct in the instrument panel has been pinched during installation, the air guide to the front windshield is uneven or insufficient. Refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .
3. Defroster Vent Side window/passenger side. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
4. Instrument Panel Vent, Right Removing and installing instrument panel vents, refer to and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
5. Right Center Instrument Panel Vent Removing and installing instrument panel vents, refer to and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
6. Left Center Instrument Panel Vent Removing and installing instrument panel vents, refer to and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
7. Instrument Panel Vent, Left Removing and installing instrument panel vents, refer to and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
8. Defroster Vent Side window/driver side. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
9. Intermediate Piece / Defrost Canal Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
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»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
13. Right Front Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
14. Heater Controls/ Base Plate Removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls)
15. Trim Panel For Right Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
16. Air Duct To Rear Right Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
17. 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»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
18. Plug Only in vehicles without air guide to vent installed in center console at rear.
19. Air Duct To Rear Left Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
20. Trim Panel For Left Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
21. Left Front Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim)
22. Heater Unit Removing and installing, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) Heater Unit, disassembling and assembling, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation)

Note. Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR .

Scheme 132

1. Fresh Air Intake
2. Removing Air From The Passenger Compartment (In 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. 7 - Outlet To Left Front Footwell Vent
8. Outlet To Defroster Vents (Instrument Panel) NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .
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.

Scheme 133

1. The indicator lamp in the fresh/recirculation button -F- will come one when air recirculation is selected (check the functionality of the fresh/recirculation air button -F-, refer to «HEATER CONTROL MODULE AND FRESH/RECIRCULATING AIR DOOR MOTOR, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-control-module-j65-and-fresh) ), Owner's manual and appropriate SYSTEM WIRING DIAGRAM.
2. By pressing fresh/recirculated air button -F-, recirculating air mode function is selected and indicator lamp in fresh/recirculated air button -F- lights up. By pressing button -F- again or switching ignition off, recirculating air mode function is switched off (motor is set to fresh air mode position after ignition is switched on). Refer to the Owner's manual.
3. So that fogged up windows can be defogged as rapidly as possible, recirculating air mode function is switched off a short time after rotary switch for air distribution -B- is set to position -D- air distribution to front windshield and switch-on indicator lamp in fresh/recirculated air button -F- goes out.

If air distribution is changed via rotary switch -B- e.g. to footwell, heater remains in fresh air mode.

Air recirculation mode is not switched off when rotary switch -B- is turned through position -D- air distribution to front windshield (e.g. out of position for air to instrument panel vents into position for air at top and bottom).

If rotary switch -B- is located in position -D- air distribution to front windshield, recirculating air mode function can be switched on via fresh/recirculated air button -F-.

INSTRUMENT PANEL OVERVIEW

1. 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»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
2. 2 - Defroster Vent For front windshield. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) . If the Intermediate piece between heater and air duct in the instrument panel has been pinched during installation, the air guide to the front windshield is uneven or insufficient. Refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) . NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .
3. 3 - Defroster Vent Side window/passenger side. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
4. 4 - Instrument Panel Vent, Right Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__instrument-panel-vent) and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
5. 5 - Right Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__instrument-panel-vent) and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
6. 6 - Left Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__instrument-panel-vent) and «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
7. 7 - Instrument Panel Vent, Left Removing and installing instrument panel vents «INSTRUMENT PANEL VENT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__instrument-panel-vent)
8. 8 - Defroster Vent Side window/driver side. Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
9. 9 - Intermediate Piece / Defrost Canal Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
10. 10 - Fresh Air Intake Air is drawn in via plenum chamber.
11. 11 - Recirculating Air Intake The air is taken from the passenger footwell under the glove compartment.
12. 12 - Air Guide/Instrument Panel Vent To center vents at left and right Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
13. 13 - Right Front Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
14. 14 - Heater Controls / Base Plate Removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .
15. 15 - Trim Panel For Right Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
16. 16 - Air Duct To Rear Right Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
17. 17 - 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»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
18. 18 - Plug Only in vehicles without air guide to vent installed in center console at rear.
19. 19 - Air Duct To Rear Left Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
20. 20 - Trim Panel For Left Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
21. 21 - Left Front Footwell Vent Removing and installing, refer to «Removal and Installation»(/audi/a3/8p-2004-2008/remont/exteriorinterior-trim/#interior-trim) .
22. 22 - Heating Removing and installing, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) . Heater, disassembling and assembling «DISASSEMBLY AND ASSEMBLY»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation) . NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or a manual A/C system, the change to this door has no impact. The door is controlled by the Climatronic Control Module -J255- whenever the heating or manual A/C system is adjusted. Refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .

HEATED REAR WINDOW -Z1

1. By pressing button -E- with ignition switched on, Vehicle Electrical System Control Module -J519- is activated by a ground signal (signal remains on for duration of button operation). As soon as the vehicle electrical system control module rear switches on the window defroster (only when the engine is running) the indicator lamp in the button -E- comes on (the vehicle electrical system control module emits a positive signal). Rear window heater is switched off either by pressing button -E- again or by switching ignition off. Refer to appropriate SYSTEM WIRING DIAGRAM and Owner's Manual.
2. If the voltage measured on terminal 30 on the vehicle electrical system control module is below a valued stored in the vehicle electrical system control module, then the Rear Window Defogger -Z1- will be switched off completely or the power will be reduced to take the load off the generator. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (for the vehicle electrical system control module).
3. The rear window defogger is controlled by the vehicle electrical system control module only when the engine is running. When the engine is off, there is no activation and no message 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 pushed. Refer to the Owner's Manual and appropriate SYSTEM WIRING DIAGRAM.
4. If it is necessary to switch off the rear window defogger for a brief period due to low voltage from the vehicle electrical system control module, the indicator lamp -E- in the defogger switch remains on. If the defogger is going to be switched off for a longer period, then the vehicle electrical system control module will switch the lamp off.
5. The test for switching on the rear window defogger is described in Guided Fault Finding for the vehicle electrical system control module and for the A/C system. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (for the vehicle electrical system control module).

Note. The rear window defogger switches off by itself after approximately 10 minutes by the vehicle electrical system control module if the outside temperature is above 0 °C. With ambient temperatures less than 0 °C in vehicles which were built from beginning of production, heated rear window is switched off by vehicle electrical system control module after approximately 20 minutes. At a later point in time, vehicle electrical system control module are installed (introduction not yet finalized) in which Heated Rear Window remains switched on until ignition is switched off (it can be switched off and back on again manually at any time). If temperature rises above 0 °C in the course of a driving cycle, rear window defroster is switched off on completion of operating period stored in vehicle electrical system control module (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 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".

Scheme 134

1. Heater Controls / Heater Control Module -J65- Different versions depending on vehicle equipment (with and without Driver Heated Seat Adjuster -E94- and Front Passenger Heated Seat Adjuster -E95-). Function, removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .
2. Heater Controls / Base Plate Removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .
3. Bowden Cable For Temperature Adjustment Removing and installing, refer to «TEMPERATURE ADJUSTMENT CABLE»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__temperature-adjustment-cable) .
4. Flexible Shaft To gear mechanism/ curved washer for activation of air distribution doors. Removing and installing, refer to «AIR DISTRIBUTION FLEXIBLE SHAFT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-distribution-flexible-shaft) .
5. Heater Unit Removing and installing, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) . Removing and reinstalling add-on components of heater, refer to «HEATER COMPONENTS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation) . Heater, disassembling and assembling, refer to «HEATER DISTRIBUTION HOUSING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation) . Air guide channel, disassembling and assembling, refer to «AIR GUIDE CHANNEL»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-guide-channel) .
6. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter) . Follow the replacement intervals, refer to «Maintenance, Diagnosis»(/audi/a3/8p-2004-2008/remont/procedures/#how-to-diagnosis-the-maintenance-maintenance-intervals) . As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element). Notes on version with activated charcoal element, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter-with-activated) .
7. Fresh Air Blower Series Resistor With Fuse -N24- Removing and installing, refer to «FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__fresh-air-blower-series-resistor-with) .
8. Fresh Air Blower -V2- Removing and installing, refer to «FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__fresh-air-blower-v2) .
9. Intake Housing With Fresh/Recirculating Air Door Removing and installing, refer to «AIR INTAKE HOUSING WITH FRESH/RECIRCULATING AIR DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-intake-housing-with-freshrecirculating-air) .
10. Fresh/Recirculating Air Door Motor -V154- Checking function, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) . Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) .
11. To Gear Mechanism With Curved Washer For Activation Of Air Distribution Doors Do not remove, adjustment cannot be reproduced.
12. Grommet Insert into the bulkhead before installing the heater, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) . Installing, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) .
13. Foam Spacer Installed between grommet and heater.
14. Actuating Arm For Activating Temperature Doors
15. Heat Core For Heater Unit Removing and installing, refer to «HEAT CORE»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
16. 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 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 Engine Control Module (ECM), refer to «TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__auxiliary-air-heater-heating-element) and appropriate SYSTEM WIRING DIAGRAM. 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»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__auxiliary-heater-heating-element-with-control) .

FASTENER TIGHTENING SPECIFICATIONS

FRESH/RECIRCULATION AIR DOOR MOTOR - V154-, CHECKING

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 not OK, then check the Heater Control Module -J65- electronics and the Fresh/Recirculating Air Door Motor -V154- activation. Refer to HEATER CONTROL MODULE AND FRESH/RECIRCULATING AIR DOOR MOTOR, CHECKING .

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.

FRESH/RECIRCULATION AIR DOOR MODE BUTTON AND MOTOR -V154-, CHECKING

Special tools and workshop equipment required

1. Voltage tester V.A.G 1527 B

Fresh/recirculating air button is installed in Heater Control Module -J65

Note. 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 as for vehicles with A/C system). The function recirculating air mode is cancelled by switching off ignition. After switching ignition on again, Fresh/Recirculating Air Door Motor -V154- is activated by Heater Control Module -J65- and heater switches from recirculating air mode to fresh air mode (when recirculating air mode was selected beforehand). So that fogged windows are defogged as rapidly as possible, only restricted recirculating air mode is possible when rotary switch for air distribution -B- is located in air to front windshield -D-. The heater control module switches, for example, to fresh air mode after the rotary switch is turned into this position (and the LED in the button goes out). Make sure the fresh/recirculating air button -F- and the fresh/recirculating air door motor work correctly. Refer to AIR RECIRCULATION BUTTON AND FRESH/RECIRCULATION AIR DOOR MOTOR CONTROL .

1. Checking the fresh/recirculated air door motor functionality, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154)
2. Checking the heater control module electronics and the fresh/recirculated air door motor, refer to «HEATER CONTROL MODULE AND FRESH/RECIRCULATING AIR DOOR MOTOR, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-control-module-j65-and-fresh) .

HEATER CONTROL MODULE -J65- AND FRESH/ RECIRCULATION AIR DOOR MOTOR -V154-, CHECKING

Special tools and workshop equipment required

1. Voltage tester V.A.G 1527 B

Note. From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. The Heater Control Module -J65- has no affect on the Start/Stop function on vehicles with only a heater (no A/C).

Remove the glove compartment. Refer to Removal and Installation .

Switch ignition on.

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).

Connect the V.A.G 1527 B -B- to check voltage at connector -A- between terminals 9 and 10 (to Fresh/Recirculating Air Door Motor -V154-).

Scheme 135

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

Ground (GND) is applied at terminal 9 continuously or only for a short time (depending on control module version) and B+ is applied at terminal 10 continuously or only for a short time.

Fresh/Recirculating air door motor and thus the fresh/recirculating air door moves into recirculating air mode position (recirculating air intake opening -C- is opened).

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

Note. By pressing fresh/recirculating air button -F-, heater control module changes the voltage supply to Fresh/Recirculating Air Door Motor (B+ and GND are interchanged). Depending on the version of the heater control module, B+ is applied continuously or only for a certain period of time after pressing the fresh/recirculating air button. If this time has elapsed, the motor is only still actuated over a certain duty cycle for control modules on which the B+ is applied only for a certain period of time (lamp in V.A.G 1527 B only still blinks on briefly).

GND is applied at terminal 10 continuously or for a short time and B+ is applied at terminal 9 continuously or for a short time.

The fresh/recirculation air door motor and the fresh/recirculation air door will move into the fresh air mode position (the 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 fresh/recirculation air door motor. Refer to FRESH/RECIRCULATION AIR DOOR MOTOR .

Not OK?

Check the wire connection between the heater control module and the fresh/recirculation air door motor for open circuit or short circuit, refer to appropriate SYSTEM WIRING DIAGRAM.

Check the voltage supply and the ground connection on the heater control module, refer to appropriate SYSTEM WIRING DIAGRAM.

Replace heater control module. Refer to HEATER CONTROLS .

HEATING PERFORMANCE, CHECKING

Note. If coolant circuit is not completely bled after filling, air may accumulate in heater core of heater, thus reducing heating performance, additional noises may occur or customer may complain of different air temperatures flowing out of vents at driver side and front passenger side.

Corrective Action For Poor Heating Output Or Noises From Coolant Circuit

Perform a lengthy test drive at high engine speed (at least 10 minutes, engine speed above 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 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 [For engine(s) CBRA] Description and Operation or refer to [For engine(s) BPY] Description and Operation or refer to [For engine(s) CCTA, CBFA] Description and Operation or refer to [For engine(s) CBEA] Description and Operation .

In vehicles with a parking/auxiliary heater, make sure the Recirculation Pump -V55- on the parking heater is working correctly and that the parking heater is incorporated side the coolant circuit.

Requirements for Reaching Maximum Heating Performance

1. Coolant circuit has been bled according to specifications, refer to «[For engine(s) CBRA] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#32l-cooling-system-engine-codes-bub-cbra) or refer to «[For engine(s) BPY] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy) or refer to «[For engine(s) CCTA, CBFA] General Information»(ref-496038-S09726818432012082100000) or refer to «[For engine(s) CBEA] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-cbea) .
2. All air ducts, covers and seals OK and properly installed.
3. Air flow through dust and pollen filter is not obstructed by dirt, check «DUST AND POLLEN FILTER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter) .
4. Engine is warm.
5. The Bowden cable and the release cable on the temperature flaps are OK.
6. Engine coolant thermostat is OK. Refer to «[For engine(s) CBRA] Diagnosis and Testing»(/audi/a3/8p-2004-2008/remont/cooling-fan/#32l-cooling-system-engine-codes-bub-cbra) or refer to «[For engine(s) CBEA] Diagnosis and Testing»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-cbea) .
7. The foam seal on the heat exchanger is OK. Refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
8. On diesel vehicles, the auxiliary heater and the Heater Control Module -J65- are OK. Refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) , and Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (perform Guided Fault Finding on the auxiliary air heater).
9. In vehicles with a gasoline direct fuel injection engine FSI, activation of Engine Control Module (ECM) by heater control module OK, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .

Test Prerequisites

1. Coolant circuit has been bled according to specifications, refer to «[For engine(s) CBRA] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#32l-cooling-system-engine-codes-bub-cbra) or refer to «[For engine(s) BPY] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy) or refer to «[For engine(s) CCTA, CBFA] General Information»(ref-496038-S09726818432012082100000) or refer to «[For engine(s) CBEA] General Information»(/audi/a3/8p-2004-2008/remont/cooling-fan/#20l-cooling-system-engine-codes-cbea) .
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. Vehicle not exposed to sunlight.

Heating Performance, Checking

Close hood.

Close doors, windows and sun roof.

Open all dash panel vents.

Measure the ambient temperature (temperature in workshop).

Start the engine.

Turn the temperature switch 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.

Note. The heater works in fresh air operation, the indicator light in the Recirculation button -D- does not light up. Fresh Air Blower runs at maximum speed.

Target Values

1. The temperature of the air coming out of the left and right vents in the instrument panel is maximum 15 °C greater than in the previously measured ambient temperature.
2. The temperature difference between the air coming out of the left and right instrument panel vents is less than 8 °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. The temperature of the air coming out of the left and right instrument panel vents increases to a value greater than 55 °C (at an engine temperature of approximately 90 °C, depending on the current engine compartment temperature).
2. The temperature difference between the air coming out of the left and right instrument panel vents 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. The temperature drops within 5 minutes to a value, which is maximum 15 °C greater than the previously measured ambient temperature

If the specified values are not reached, check the following

1. If the required heat output is not reached

Ventilation of coolant circuit: [For engine(s) CBRA] Description and Operation or refer to [For engine(s) BPY] Description and Operation or refer to [For engine(s) CCTA, CBFA] Description and Operation or refer to [For engine(s) CBEA] Description and Operation .

Incorporation of heater core for heater into coolant circuit [For engine(s) CBRA] Description and Operation or refer to [For engine(s) BPY] Description and Operation or refer to [For engine(s) CCTA, CBFA] Description and Operation or refer to [For engine(s) CBEA] Description and Operation .

Bowden cable for setting the temperature and operating the temperature doors, refer to TEMPERATURE ADJUSTMENT CABLE .

The foam seal on the heater core, 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 [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 .

1. If the air coming out of the vents is too warm when it is set to Cold

Bowden cable for setting the temperature and operating the temperature doors, refer to TEMPERATURE ADJUSTMENT CABLE .

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

The plenum chamber and seal between engine compartment and plenum chamber.

SEAT HEATER ACTIVATION, TESTING

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. Vehicle Diagnostic, Testing and Information System VAS 5051 A with Multimeter Leads VAS 5051/7

Scheme 136

Scheme 137

1. The Heater Control Module -J65- 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 Heater 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 GND e.g. at connector -B- terminal 20) with engine running. The voltage is transferred via connector -B- (from terminal 11 to Driver Seat Heater Control Module -J726- and from terminal 15 to Front Passenger Seat Heater Control Module -J727-). Refer to appropriate SYSTEM WIRING DIAGRAM.

Note. Resistance of seat heater potentiometer is dependent on the knurled wheel position, it cannot be measured using workshop equipment. Check function of seat heater and service it. and appropriate SYSTEM WIRING DIAGRAM. Beginning with MY 2009 and as a running change, seat heating control modules are being installed that control the seat heating temperature at a lower characteristic curve. 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".

ENGINE CONTROL MODULE (ECM) ACTIVATION, TESTING

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. Vehicle Diagnostic, Testing and Information System VAS 5051 A with Multimeter Leads VAS 5051/7

Note. These functions are dependent on the version of the engine and of the ECM and are not present on all vehicles. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (for the respective ECM) and appropriate SYSTEM WIRING DIAGRAM. On vehicles with a manual climate control system, the A/C Control Module -J301- exchanges the information via the data bus system with each ECM. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

1. The Heater Control Module -J65- has a potentiometer installed. This potentiometer is operated via rotary switch for temperature preselect -A- and therefore transmits position of temperature dial to ECM.

On vehicles with diagram-mapped cooling, activation of Map Controlled Engine Cooling Thermostat -F265- is influenced by the respective ECM on certain engines. If rotary switch for temperature preselect -A- is located at Warm stop or closely in front of it, coolant temperature is reduced (limited to approximately 95 °C) to prevent excessive air blower temperatures from heater air vents. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function (for respective ECM).

In vehicles with gasoline direct fuel injection engine FSI, mixture formation is influenced by respective ECM on certain engines. If rotary switch for temperature preselect -A- in area of Warm stop or closely in front of it, improved coolant heating (and thus better heating performance) is attained by departing the stratified charge range for engine mixture formation and the engine runs normally. Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function (for respective ECM).

In vehicles for which this function is designated, a voltage of approximately 5 volts is supplied the ECM at connector -B- between terminal 1 and 10 with ignition switched on. Check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function (for respective ECM) and appropriate SYSTEM WIRING DIAGRAM.

A voltage between approximately 0.5 V (cold) and approximately 4.5 V (warm) is sent via terminal 2 inside the connector -B- to the heater control module -A- depending on the position of the temperature preset rotary switch -A- Each ECM knows the position of the temperature preset rotary switch -A- by this voltage. The ECM evaluates this voltage and then controls the coolant temperature and the mixture formation. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function.

AUXILIARY AIR HEATER HEATING ELEMENT - Z35- ACTIVATION, TESTING (WITHOUT A/C)

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. Vehicle Diagnostic, Testing and Information System VAS 5051 A with Multimeter Leads VAS 5051/7

Only installed on vehicles with Diesel engine

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 in the event a there is a request from the heater controls (Heater Control Module -J65-). The electric auxiliary air heater is controlled by the Auxiliary Air Heater Control Module -J604- or by the Engine Control Module (ECM) (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 in "Guided Fault Finding" function for respective ECM and appropriate SYSTEM WIRING DIAGRAM. 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 -Z35- via the auxiliary air heater control module. 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 ECM. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function for respective ECM and appropriate SYSTEM WIRING DIAGRAM. 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 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. 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 air heater heating element is described in Guided Fault Finding of the respective ECM using Vehicle Diagnosis, Testing and Information System VAS5051. At this time, no auxiliary heater is installed in vehicles with gasoline engine, also the parking heater is not activated as auxiliary heater. 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 air 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 air heater heating element is switched on again. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Check Activation Of Heater Controls (Heater Control Module -J65-)

1. The heater control module has a switch. This switch is operated (closed) via rotary switch for temperature preselect -A- in area from approximately 3 o'clock position up to "warm" stop.

If the switch for the auxiliary heater is closed, then the electronics in the heater control module will switch through terminal 7 ground to the auxiliary air heater control module -J604- / to the respective engine control module with the ignition turned on. Auxiliary air heater control module / ECM detects that additional heating performance is desired and switches on the electric auxiliary heater when the other switch-on requirements necessary for activation have also been met.

1. Switch-on conditions for electric auxiliary air heater (activation of Auxiliary Air Heater Heating Element) from the Auxiliary Air Heater Control Module. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function.
2. Switch-on conditions for parking heater as auxiliary heater (in Auxiliary Heater Control Module) on vehicles with this optional parking heater.
3. Switch-on conditions for electric auxiliary air heater (activation of Auxiliary Air Heater Heating Element) from ECM. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function for ECM.

Note. In order for each ECM to control the 3-stage Auxiliary Air Heater Heating Element via the Low Heat Output Relay and the High Heat Output Relay, the ECM must fulfill the same conditions, which are also required in the A/C Control Module -J301- on vehicles with a manual A/C system. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

Switch-On Criteria For Electric Auxiliary Air Heater Activation

The ECM actuates Auxiliary Air Heater Heating Element via Low Heat Output Relay and High Heat Output Relay in the event the following requirements are met

1. There is a GND signal at ECM from Heater Control Module.
2. Engine is running for a minimum of 8 seconds and engine speed is greater than 500 RPM.
3. Engine temperature is lower than 75 °C.
4. The calculated outside air temperature is lower than 8 °C.
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 DTC is stored in ECM and generator load is less than 30 to 77% (depending on engine speed).

Note. On vehicles with a 3-stage auxiliary air 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 VAS 5051 in the "Guided Fault Finding" (for ECM) and appropriate SYSTEM WIRING DIAGRAM. Thus the next stage is switched on only in the event generator load is less than 30 to 77%, depending on engine speed.

Switch-Off Criteria For Auxiliary Heater Activation

Note. On vehicles without A/C system, activation is switched off as soon as one of the switch-on requirements is no longer met in ECM or one of the switch-off criteria is detected.

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. There is no longer a GND signal at ECM from Heater Control Module.

AIR INTAKE HOUSING WITH FRESH/RECIRCULATING AIR DOOR

Removing

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

Remove the heater. Refer to HEAT EXCHANGER .

Remove bolts -A-.

Scheme 138

Remove the cover -B-.

Disconnect connector -C-.

Disengage air intake housing -D- from heater.

Installing

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

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

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

FRESH AIR BLOWER SERIES RESISTOR WITH FUSE -N24

Remove the glove compartment. Refer to Removal and Installation .

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

Scheme 139

Disconnect harness connector -A- from series resistor -B-.

Scheme 140

Open locking mechanism -C- and slide the series resistor -B- to the right -arrow

Remove series resistor -B- from heater (out of heating and A/C unit of manual climate control system).

FRESH AIR BLOWER -V2

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 141

Disconnect connector -D-.

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

Note. Connection between fresh air blower housing -C- and heater (heating A/C unit of manual climate control system) may be sealed with sealing compound, in this case a great use of force is required for rotating. Fresh Air Blower -V2- is installed in housing -C- and cannot be replaced separately.

Remove fresh air blower housing -C- from the heater (from the A/C unit on vehicles with a manual climate control system).

Installing

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

Make sure the fresh air blower works correctly after installing it.

Note. Observe correct seating position when installing the fresh air blower in heater (in heating and A/C unit in a manual climate control system). After installing, check seat of fresh air blower housing in heater (in heating A/C unit in a manual climate control system) and function of fresh air blower. Note that there are different versions of fresh air blower for vehicles without A/C (only with heater), with manually regulated and automatically regulated A/C system.

FRESH/RECIRCULATION AIR DOOR MOTOR - V154- / -V113

Fresh/recirculation air door motor -V154- on vehicles without A/C

Recirculation door motor -V113- on vehicles with manual A/C

Note. The designation of the control motor in the Guided Fault Finding is different in the wiring diagram for the heater and the manual climate control system, the procedure for removal and installation is however the same. Make sure the fresh/recirculation air door motor and the Heater Control Module -J65- are working correctly. Refer to FRESH/RECIRCULATION AIR DOOR MOTOR AND FRESH/RECIRCULATION AIR BUTTON, CHECKING (vehicles without A/C). Make sure the recirculation door motor and the A/C Control Module -J301- are working correctly. After installing a new motor (for the heater), check activation by Heater Control Module, refer to FRESH/RECIRCULATION AIR DOOR MOTOR AND FRESH/RECIRCULATION AIR BUTTON, CHECKING and function of Fresh/Recirculating Air Door Motor (correct position for fresh/recirculating air mode). After installing a new motor on the manual climate control system, check activation by A/C control module and check the function of recirculation door motor (correct position for fresh/recirculating air mode). Fresh/Recirculating Air Door Motor (Recirculation Door Motor) can only be removed without difficulty in fresh air mode stop position 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. Different control motor versions on vehicles without an A/C system (heating only), with manual A/C system and automatic A/C system (with end switches or potentiometer).

Removing

If necessary, switch on ignition and wait until motor has reached its end position fresh air mode.

Switch off ignition.

Remove the glove compartment. Refer to Removal and Installation .

Disengage catches -B- and -C- for bracket -A- on intake housing and remove bracket -A-.

Scheme 142

Remove motor -B- (in direction of arrow) from intake housing.

Scheme 143

Note. Connection between motor toothed gears and back pressure door is designed so that the motor can only be removed in the fresh air mode position without difficulty (intake opening for recirculating air mode is sealed via the fresh/recirculating air door -A-). 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 -C-, ensure that toothed gear -D- 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 fresh/recirculating air door. If a motor was removed in a different position or activated in the removed state, it cannot be installed. If the motor toothed gear -A- does not stand at stop -B- fresh air mode, bring it into the position required for installation.

Set toothed gear on control motor to the fresh air mode position

While in the removed state, connect the control motor to the vehicle wiring harness (via the connector provided for it).

Switch ignition on (Heater Control Module / A/C Control Module activates motor so that it moves into fresh air mode stop position).

Wait until toothed gear -A- of motor reaches stop -B- fresh air mode.

Switch off ignition.

Control Motor, Installing

Switch off ignition.

Connect control motor to vehicle wiring harness via the connector provided.

Reach into intake opening for recirculating air mode and bring fresh/recirculating air 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-.

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

Scheme 144

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-, take special care when doing this, that bracket guide -D- is inserted correctly into intake housing mount -E- and bracket is engaged correctly in both catches -B- and -C-.

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

Note. Position of motor (and of door) is no longer visible with glove compartment installed, therefore it is sensible to check its function before installing glove compartment, refer to FRESH/RECIRCULATION AIR DOOR MOTOR AND FRESH/RECIRCULATION AIR BUTTON, CHECKING , (on vehicles with A/C) or Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function (on vehicles with manual A/C) If both toothed gears are assembled in incorrect position, fresh/recirculating air door does not reach its two end positions or motor does not run cleanly and without hitching.

Switch ignition on.

Check the fresh/recirculating air door motor (on the recirculation door motor) and the control via the Heater Control Module, refer to FRESH/RECIRCULATION AIR DOOR MOTOR AND FRESH/RECIRCULATION AIR BUTTON, CHECKING (on vehicles without A/C) or the A/C Control Module or Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding" (on vehicles with manual A/C).

Activate the respective motor for as long until toothed gear -D- contacts stop fresh air mode or stop recirculating air mode and then check position of fresh/recirculating air door -A-, it must be open (recirculating air mode) or closed (fresh air mode).

Install all removed components in reversed order.

HEATER AND A/C SYSTEM CONTROLS

Heater controls, Heater Control Module -J65- on vehicles without A/C system

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

Note. Heater Control Module (A/C Control Module) -A- is available in different versions (with and without heated seat adjusters (Driver Heated Seat Adjuster -E94- and Front Passenger Heated Seat Adjuster -E95- -C-). From MY 2010, this vehicle has a Start/Stop System for specific engines as optional equipment. The heater control module has no affect on the Start/Stop function on vehicles with only a heater (no A/C). 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. The A/C control module does not limit the Stop function when the cooling mode is on. 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 (ECM). Refer to [For engine(s) CBRA] AFTER-RUN COOLANT PUMP or refer to [For engine(s) BPY] AFTER-RUN COOLANT PUMP OVERVIEW or refer to [For engine(s) CCTA, CBFA] AFTER-RUN COOLANT PUMP -V51 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. The heater controls (heater control module) -A- do not have a DTC memory (Guided Fault Finding is not possible) and are not connected to the CAN-Bus system. A/C system controls (A/C control module) -A- is equipped with DTC memory (Guided Fault Finding is possible) and connected to the CAN-Bus system, therefore check DTC memory if necessary before removing using Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding".

Removing

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

Pull off trim panel for heater controls -A- (A/C system controls).

Scheme 145

Note. If necessary, lift the trim carefully using a small screwdriver

Remove bolts -B- and -C-.

Disengage heater control module (A/C control module) -D- from the center console.

Disengage harness connector release catch -A- by pulling in direction of arrow.

Scheme 146

Disengage harness connector release catch -B- to connector -arrow- and disconnect connector -C-.

Disengage harness connector release catch -D- and disconnect connector -D-.

Disengage the connector -C- (only on the A/C control module) in the same way as connector -B- and disconnect it.

Installing

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

Both shafts of heater control module -C- can be slid into mounts of base plate -D- only in one position, therefore turn rotary switches -A- and -B- for as long until position of both shafts align with position of shaft mounts in base plate.

Scheme 147

Air distribution shafts of A/C control module -C- can be slid into mounts of base plate -D- only in one position, therefore turn rotary switch -B- for as long until position of both shafts align with position of shaft mounts in base plate.

Locking mechanisms of adjusting lever -D- and -F- are installed in base plate of heater controls -A- (for production, so that setting is not offset during delivery), these locking mechanisms are released via pin -C- (for air distribution) and -E- (for temperature setting, only on version for vehicles without A/C system) of heater control module (A/C control module) -B- when connecting. If pins -C- (and -E- on version for vehicles without A/C system) are not inserted correctly, the corresponding rotary switch can only be moved with difficulty or makes clicking sounds when turning.

Scheme 148

BASE PLATE FOR HEATER AND A/C SYSTEM CONTROLS

Note. Base plate -C- is different between vehicles without A/C system (with a control for Bowden cable to temperature door -E-) and with manually regulated A/C system (without a Bowden cable control -E-, the temperature door is moved by a control motor). A step-up gear for operating the flexible shaft -H- (for air distribution) is installed in base plate -C-. The flexible shaft -H- rotates 2 times for one switch rotation via the step-up gear on heater / on heating A/C unit and on base plate of heater / A/C system controls -C-, refer to AIR DISTRIBUTION FLEXIBLE SHAFT .

Removing

Bring rotary switch for temperature preselect -A- into position cold stop (only on vehicles without A/C system).

Remove the glove compartment. Refer to Removal and Installation .

Remove the front passenger footwell vent.

Remove Heater Control Module -J65- (A/C Control Module -J301-). Refer to HEATER AND A/C SYSTEM CONTROLS .

Remove bolts -A-.

Scheme 149

Remove the mounting frame -B-.

Reach into center console and release lug for flexible shaft -H-.

Reach into center console and disengage locking mechanism -D- of Bowden cable sheath -E- and remove Bowden cable sheath from mount (only present on vehicles without A/C system).

Reach into center console and release ball on Bowden cable -F- from operating lever -G- (only present on vehicles without A/C system).

Remove base plate from center console -C

Installing

Note. A set of gears is installed in base plate for heater / A/C -C- controls and in heater / in heating and A/C unit. Flexible shaft -H- rotates twice for one rotation of air distribution rotary button. Since door positions are not visible with instrument panel installed, therefore pay attention to position of air distribution doors when connecting flexible shaft -H- to base plate.

Connect Bowden cable for temperature door onto base plate -A- (only present on vehicles without A/C system).

Connect base plate -D- to heater control module (A/C control module) -C-, refer to HEATER AND A/C SYSTEM CONTROLS .

Bring rotary switch -D- into the position in which the flexible shaft -C- can be inserted into mount of base plate -A-.

Scheme 150

Insert flexible shaft -C- into base plate -A

Bring rotary switch -D- into air in footwell position (as shown).

Check position of right footwell door -E-, air guide channel -F- must be opened completely.

Air guide channel -F- is closed

Release flexible shaft -C- from base plate -A

Turn rotary switch -D- into air distribution to front windshield position (approximately 180°).

Insert flexible shaft -C- into base plate -A

Bring rotary switch -D- into air in footwell position (as shown).

Check position of right footwell door -E-, air guide channel -F- must be opened completely.

The rest of the installation is performed in the reverse order of removal.

AIR DISTRIBUTION FLEXIBLE SHAFT

Removing

Remove the glove compartment. Refer to Removal and Installation .

Bring flexible shaft -C- into position in which lug -D- for shaft is visible in heater (heating A/C unit) gears -F- by turning rotary switch for air distribution -B-.

Scheme 151

Disengage base plate of heater controls (A/C system controls) from center console, refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE .

Note. Bowden cable for temperature door (only present on heater controls) must not be removed.

Remove flexible shaft -C- from base plate -A-, refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE .

Using a small screwdriver, carefully lift lug -D- in mount -E- and pull flexible shaft out of mount in heater (heating A/C unit) gearing.

Installing

Note. A set of gears is installed in base plate for heater / A/C -A- controls and in heater / in heating and A/C unit. Flexible shaft -B- rotates twice for one rotation of air distribution rotary button.

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

Since door positions are not visible with instrument panel installed, therefore pay attention to procedures for connecting flexible shaft to base plate, refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE .

TEMPERATURE ADJUSTMENT CABLE

Note. Temperature adjustment Bowden cable is present only on vehicles without A/C system. On vehicles with A/C system, a motor moves the temperature door. Base plate -C- is different between vehicles without A/C system (with a control for Bowden cable to temperature door -E-) and with manually regulated A/C system (without a Bowden cable control -E-).

Removing

Bring rotary switch for temperature preselect -A- into position cold stop.

Remove heater controls (Heater Control Module -J65-), refer to HEATER CONTROLS .

Remove the instrument panel and the instrument panel cross-member (central tube). 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.

Disengage lug -D- of Bowden cable sheath -E- and remove Bowden cable sheath from mount of base plate for heater controls.

Scheme 152

Disengage ball on Bowden cable -F- from operating lever -G

Disengage support bracket -A- of Bowden cable sheath -E- and remove Bowden cable sheath from heater guide -C-.

Disengage ball on Bowden cable -B- from temperature door lever.

Installing

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

Only install a Bowden cable which has not been kinked and can move easily in Bowden cable sheath.

Do not kink Bowden cable.

HEATER UNIT

Special tools and workshop equipment required

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

1. Heating performance, checking, refer to «HEATING PERFORMANCE, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heating-performance-checking) .

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 Description and Operation . When removing bolts, take note of the length and assignment of bolts for re-installation. All cable ties opened or cut during removal of heater 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.

Switch off ignition.

Protect driver and front passenger seats using seat covers.

Disconnect Battery, refer to [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation .

Dissipate pressure in coolant circuit by opening cap at coolant expansion tank. 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 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 .

Scheme 153

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 . 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 present and it becomes necessary, disengage heat shield -B- from bulkhead and set it aside (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 154

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 heater (e.g. using 3093) and remove them.

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

Scheme 155

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 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 accelerator pedal module. Refer to [For engine(s) BPY, CBFA, CBRA, CCTA] ACCELERATOR PEDAL MODULE WITH THROTTLE POSITION SENSORS .

Remove the left and right vents -C-.

Scheme 156

Fold back the carpet on the driver and front passenger sides so that it is possible to remove the footwell vents for the back of the passenger compartment -A- and -B-. Refer to Removal and Installation .

Remove both rear footwell vents -A- and -B-.

Remove the Fresh Air Blower -V2-, refer to FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM .

Remove heater controls (Heater Control Module -J65-), do not remove base plate for heater controls, refer to HEATER AND A/C SYSTEM CONTROLS .

Remove the instrument panel and the instrument panel cross-member (central tube). 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 .

Scheme 157

Remove bolts -B- and release bracket -A- from heater (bracket remains on wiring harness secure to vehicle).

Remove both bolts -A- on bracket for wiring harness -B-.

Scheme 158

Disconnect the connector -C-.

Loosen securing ties of vehicle wiring harness on heater.

On vehicles with an electric auxiliary heater (on vehicles with Diesel engine), disconnect wire connections to voltage supply for the Auxiliary Air Heater Heating Element -Z35-. Refer to AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE .

Disconnect all electrical connections between vehicle wiring harness and the electrical components of heater at harness connectors.

Note. Wiring harness heater is removed along with heater.

Carefully pull right side of heater slightly toward rear (far enough that bolt -B- on right bracket -A- can be loosened).

Scheme 159

Note. Only pull carefully on the heater so that bracket -A- does not break. To loosen the screw -B-, reach between heater 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 heater (bracket remains on wiring harness secure to vehicle).

Disengage flange for coolant pipes to heater core -A- from pass-through of grommet -B-.

Scheme 160

Note. When removing heater, 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 the heater -A- toward the passenger side (the arrangement and the shape of the housing on vehicles without A/C is the same as on those with A/C).

Scheme 161

Installation

Installation is reverse of removal, noting the following

Two technicians are needed to install the heater.

Note. Before installing, check all gaskets and seals on heater for damage and replace if necessary. Check securing of coolant pipes to heat exchanger.

Insert the molded seal -A- (working from passenger compartment) into bulkhead -B-, make sure that molded seal -A- is positioned properly in bulkhead.

Scheme 162

Ask a colleague for assistance to install the heater.

When installing heater, have the assistant guide the flange for coolant pipes to heater core -A- through pass-through of grommet -B-.

Note. When installing heater, 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.

Reinstall removed components in reverse order of removal except storage compartment driver side.

Note. When installing the instrument panel, make sure that the intermediate piece for defrost fits properly on heater 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

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, paying close attention to the connection between coolant hoses and heater core, refer to HEAT EXCHANGER . Also 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 .

Make sure the grommet -B- fits correctly in the bulkhead.

Seal off flanges for coolant pipes to heater core -A- at pass-through of grommet -B- against ingress of water using silicon adhesive sealant if necessary.

Reinstall driver side storage compartment and remaining removed components.

Check heater function.

Check air flow direction of vent, as depending on switch position (flexible shaft rotates twice for one switch rotation via set of gears on heater and on heater controls, refer to HEATER AND A/C SYSTEM CONTROL BASE PLATE .

Scheme 163

1. Wiring Harness For Heater Different versions (e.g. with or without connection to Auxiliary Air Heater Control Module -J604-). Mark the allocation before disconnecting the connectors (connectors of same shape for different components). 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.
2. Screw
3. Heater Controls (Heater Control Module -J65-) Different versions depending on vehicle equipment (with and without Driver Heated Seat Adjuster -E94- and Front Passenger Heated Seat Adjuster -E95-). Function, removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .
4. Base Plate For Heater Controls Removing and installing, refer to «HEATER CONTROLS»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-controls) .
5. Bowden Cable For Temperature Adjustment Removing and installing, refer to «TEMPERATURE ADJUSTMENT CABLE»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__temperature-adjustment-cable) .
6. Auxiliary Air Heater Heating Element -Z35- (with Auxiliary Air Heater Control Module -J604-) The electric auxiliary air heater is available in different versions. Diesel vehicles, which were built through November 2006 (running change in production), the auxiliary air heater heating element is controlled by the auxiliary air heater control module. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding". 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 ECM. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function and appropriate SYSTEM WIRING DIAGRAM. 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»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__auxiliary-heater-heating-element-with-control) .
7. Cover For Coolant Pipes And Heater Core This illustration shows version for vehicles with Auxiliary Air Heater Heating Element. Different versions for vehicles with or without auxiliary air heater heating element (opening for auxiliary air heater heating element is sealed by this cover in vehicles without auxiliary air heater heating element).
8. Screw
9. Heater Unit Removing and installing, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) . Heater, disassembling and assembling, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation) . Air guide channel, disassembling and assembling, refer to «AIR GUIDE CHANNEL»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-guide-channel) .
10. Cover and Bracket For Fresh/Recirculation Air Door Motor -V154- Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) . 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»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) .
11. Fresh/Recirculating Air Door Motor -V154- Checking function, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR, CHECKING»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) . Removing and installing, refer to «FRESH/RECIRCULATION AIR DOOR MOTOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__freshrecirculation-air-door-motor-v154) .
12. Foam Seal Intake housing seal of heater to vehicle.
13. Intake Housing With Fresh/Recirculating Air Door Do not disassemble. Removing and installing, refer to «AIR INTAKE HOUSING WITH FRESH/RECIRCULATING AIR DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-intake-housing-with-freshrecirculating-air) .
14. Fresh Air Blower Series Resistor With Fuse -N24- Removing and installing, refer to «FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__fresh-air-blower-series-resistor-with) .
15. Fresh Air Blower -V2- Removing and installing, refer to «FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__fresh-air-blower-v2) .
16. Insulation Mat
17. Screw Clips
18. Cable Ties
19. Wiring Harness Bracket
20. Flexible Shaft To gear mechanism/ curved washer for activation of air distribution doors. Removing and installing, refer to «AIR DISTRIBUTION FLEXIBLE SHAFT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-distribution-flexible-shaft) .

Remove the heat exchanger. Refer to HEAT EXCHANGER .

Remove add-on components from heater, refer to HEATER COMPONENTS .

Scheme 164

1. Air Distribution Housing For Heater Do not disassemble further. In vehicles without Auxiliary Air Heater Heating Element -Z35-, the cover for heater core seals the opening for auxiliary air heater heating element. If necessary, coat bearing areas and guides of temperature doors thinly with grease (e.g. with G 052 745 A3) NOTE: Beginning November 2007, a heater 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. On vehicles not equipped with A/C (just heating) or on vehicles equipped with a manual climate control system, this change has no impact on the heater control or on the manual A/C system (the flaps is operated by the heater controls and/or the manual A/C), refer to «AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning) .
2. Screw
3. Air Guide Channel To Left Footwell Vent Heater version.
4. Heat Core For Heater Unit Removing and installing, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
5. Sealing Ring Replace. Coat thinly with coolant and insert on proper side, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
6. Clip Replace. Ensure it is seated correctly. Removing and installing, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
7. Screw Tightening specification 2.5 Nm.
8. Coolant Pipes Disconnecting and connecting from heater core, refer to «HEAT EXCHANGER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__heat-exchanger) .
9. Foam Spacer Installed between grommet and heater.
10. Grommet insert into the bulkhead before installing the heater, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) . Installing, refer to «HEATER UNIT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__heater-unit) .
11. Air Guide Channel Disassembling and assembling, refer to «AIR GUIDE CHANNEL»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#heating-ventilation__air-guide-channel) .
12. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter) . Follow the replacement intervals, refer to «Maintenance, Diagnosis»(/audi/a3/8p-2004-2008/remont/procedures/#how-to-diagnosis-the-maintenance-maintenance-intervals) . As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element). Notes on version with activated charcoal element, refer to «DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter-with-activated) .
13. Cover for Dust And Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/a3/8p-2004-2008/remont/automatic-hvac-system/#air-conditioning__dust-and-pollen-filter) .
14. Air Guide Channel To Right Footwell Vent Heater version.
15. Plug Installed only in vehicles without air duct to vent in rear center console (vent is not installed at this time, introduction not yet finalized).

AIR GUIDE CHANNEL

Remove add-on components from heater, refer to HEATER UNIT ADD-ON COMPONENTS .

Remove air guide channel from the heater. Refer to HEATER UNIT .

Scheme 165

1. Lower Section Of Air Guide Channel
2. Noise Insulation In vehicles without A/C system (with heater only), a foam core piece is installed for noise insulation instead of evaporator.
3. Clip
4. Upper Section Of Air Guide Channel
5. Screw

SPECIAL TOOLS

Special tools and workshop equipment required

1. Hose Clamps, Up to 40 mm. 3093
2. Hose Clamps Up to 25 mm dia. 3094
3. Cooling system tester V.A.G 1274 (and corresponding adapter)
4. Voltage tester V.A.G 1527 B
5. Test Box 105 Pin V.A.G 1598/42-1 and Test Adapter V.A.G 1598/47
6. Vehicle Diagnostic, Testing and Information System VAS 5051 A with Multimeter Leads VAS 5051/7
7. Compressed air gun, commercially available

See also:
• VENT FRAME, CHECKING
• [For engine(s) CBRA] AFTER-RUN COOLANT PUMP
• [For engine(s) BPY] AFTER-RUN COOLANT PUMP OVERVIEW
• AIR DISTRIBUTION HOUSING DEFROSTER OUTLET DOOR
• Maintenance, Diagnosis
• Removal and Installation
• INSTRUMENT PANEL VENT
• DUST AND POLLEN FILTER
• DUST AND POLLEN FILTER WITH ACTIVATED CHARCOAL INSERT
• HEAT CORE
• AUXILIARY HEATER HEATING ELEMENT WITH CONTROL MODULE
• Removal and Installation
• CHECKING AND CLEANING PLENUM CHAMBER WATER DRAIN
• [For engine(s) CBRA] Description and Operation
• [For engine(s) CBEA] Description and Operation
• AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT
• Removal and Installation
• Description and Operation
• [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation
• [For engine(s) CBRA] Removal and Installation
• [For engine(s) BPY] Removal and Installation
• [For engine(s) BPY, CBFA, CBRA, CCTA] ACCELERATOR PEDAL MODULE WITH THROTTLE POSITION SENSORS
• [For engine(s) CBRA, BPY, CCTA, CBFA] Removal and Installation
• INSTRUMENT PANEL OVERVIEW
• AIR DISTRIBUTION HOUSING OVERVIEW
• CONTACT CORROSION
• HVAC OVERVIEW
• HEATED REAR WINDOW
• TESTING SEAT HEATER ACTIVATION
• TESTING ENGINE CONTROL MODULE (ECM) ACTIVATION
• TESTING AUXILIARY HEATER ACTIVATION, WITHOUT A/C
• HEATER AND A/C SYSTEM CONTROL BASE PLATE
• HEATER CONTROL MODULE
• FRESH AIR BLOWER SERIES RESISTOR, MANUALLY REGULATED A/C SYSTEM
• HEATER CONTROLS
• HEATER UNIT
• HEATER CONTROL MODULE AND FRESH/RECIRCULATING AIR DOOR MOTOR, CHECKING
• TEMPERATURE ADJUSTMENT CABLE
• AIR DISTRIBUTION FLEXIBLE SHAFT
• AIR GUIDE CHANNEL
• FRESH AIR BLOWER, MANUALLY REGULATED A/C SYSTEM
• AIR INTAKE HOUSING WITH FRESH/RECIRCULATING AIR DOOR
• FRESH/RECIRCULATION AIR DOOR MOTOR, CHECKING
• FRESH/RECIRCULATION AIR DOOR MOTOR AND FRESH/RECIRCULATION AIR BUTTON, CHECKING
• HEATER AND A/C SYSTEM CONTROLS
• HEATING PERFORMANCE, CHECKING