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Heating, Ventilation (roadster) Audi TT 8J

Automatic HVAC System 8 illustrations ~5090 words

SERVICING HEATER SYSTEM

WARNINGBefore working on electrical system (wiring), remove relevant fuse(s).

Note. Disconnect battery before starting electric welding work on vehicle. Refer to [For transmission(s) 02E] Removal and Installation .

  1. Contact corrosion. Refer to «CONTACT CORROSION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__contact-corrosion) .
  2. Notes for performing Guided Fault Finding on the heating, refer to «PERFORMING GUIDED FAULT FINDING ON HEATING SYSTEM»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__performing-guided-fault-finding-on-heating) .
  3. Checking the electrical components on the heating system, refer to «HEATING SYSTEM ELECTRICAL COMPONENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__heating-system-electrical-components) .
  4. Checking the electrical components actuated by the heating system, refer to «ELECTRICAL COMPONENTS CONTROLLED BY HEATING SYSTEM, CHECKING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__electrical-components-controlled-by-heating-system) .

CONTACT CORROSION

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

Note. Always install new parts if there is any doubt as to whether parts can be reused. Damage due to contact corrosion is not covered by warranty.

PERFORMING GUIDED FAULT FINDING ON HEATING SYSTEM

  1. Heating system OBD is performed in the "Guided Fault Finding" function with the Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  2. The Climatronic control module -J255-, can currently be exchanged as usual, component protection is not active at this time. Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  3. If the Climatronic control module -J255- is supposed to be replaced, check the coding and adaptation before removing it using the "Replace Control Module" function, starting with Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

HEATING SYSTEM ELECTRICAL COMPONENTS

The electrical components for the heating system are identical to the electrical components for the A/C system. The electrical test for the various heater components is done in the same way as the test for these components in the A/C system. Refer to CHECKING ELECTRICAL COMPONENTS and Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

On vehicles with no A/C, only a heater, various components that are required for control on vehicles with A/C are not installed (A/C Compressor Regulator Valve -N280-, Right Temperature Door Motor -V159-, Interior Temperature Sensor Fan -V42- etc.). Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function and appropriate SYSTEM WIRING DIAGRAM.

Note. The function "electrical testing" is not described in this Repair information. Perform the electronic test with "Guided Fault Finding". This also contains information on the functions that should be tested. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

HEATER ACTIVATION AND CONTROL COMPONENTS

Note. If there is a malfunction in the system, first check the Climatronic control module -J255- DTC memory. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. If no fault is displayed, read the measured value block for the Climatronic control module and activate the component with the "output diagnosis test mode" function on the Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. Electrical checking of the various control motors, potentiometers and senders is described in Guided Fault Finding. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

  1. Perform the following work after completion of repair operations

Check Climatronic control module -J255- DTC memory and erase any possible displayed malfunctions using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

Check coding of Climatronic control module using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

If necessary, check adaptation of the Climatronic control module using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

Perform heater basic setting, Climatronic control module using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

  1. Components outside passenger compartment, refer to «COMPONENTS OUTSIDE PASSENGER COMPARTMENT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster) .
  2. Components inside the passenger compartment, refer to «A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, LEFT SIDE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster) and «A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, RIGHT SIDE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster) .

Scheme 229

Scheme 229: COMPONENTS OUTSIDE PASSENGER COMPARTMENT
Scheme 229: COMPONENTS OUTSIDE PASSENGER COMPARTMENT
  1. Forced Air Extractor A forced air extraction vent is installed at left and right under rear bumper. Sealing doors on air extraction vent must be able to move freely and close automatically. In order for the passenger compartment ventilation to function properly, the air ducts that run through the luggage compartment trim must be unobstructed. Checking, refer to «PASSENGER COMPARTMENT FORCED AIR EXTRACTION, CHECKING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__passenger-compartment-forced-air-extraction-checking) .
  2. Intake Grille For Fresh Air Intake Check for proper seating, prevents foreign objects (e.g. leaves) entering intake housing of heater unit. Check the bonded seal for damage and proper seating. This seal prevents water from flowing through beneath the intake grille into heater intake housing. Removing and installing, refer to «FRESH AIR INTAKE COVER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__fresh-air-intake-cover) .
  3. Fresh Air Intake Cover Check the bonded seal for damage and proper seating. This seal prevents water between the windshield lower frame and the cover from getting into the heater air intake shroud. Removing and installing, refer to «FRESH AIR INTAKE COVER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__fresh-air-intake-cover) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exterior-body-panels/#body-front-roadster) .
  4. Coolant Fan -V7- and Coolant Fan 2 -V177- In standard vehicle operation, the radiator fan is not activated by the Climatronic control module -J255-. It will be displayed in the heater control head measured values block that the fan is not activated. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. The request to switch on the Coolant Fan -V7- is only transmitted by the Climatronic control module in "Output Diagnostic Test Mode (DTM)" via the databus system to the engine control module (ECM). Then, with the engine running, the ECM activates the fan (Coolant Fan -V7- and Coolant Fan 2 -V177-) directly or via the Coolant Fan Control Module -J293-. Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function and «[For engine(s) CETA, CCTA] Description and Operation»(ref-505738-S14812137632012100100000) or to «[For engine(s) CDMA] Description and Operation»(ref-505739-S05274091452012100100000) or to «[For engine(s) BPY] Description and Operation»(/audi/tt/8j-2006-2010/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy-roadster) . With engine running, the respective engine control modules switches, for example, the Coolant Fan and Coolant Fan 2 (directly via the Coolant Fan Control Module) continuously to the desired output (depending on engine type). Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function and appropriate SYSTEM WIRING DIAGRAM.
  5. Outside Air Temperature Sensor -G17- The measured value of the Outside Air Temperature Sensor is not used by the Climatronic control module -J255- for controlling the heater. However, the measured value is used to calculate the permitted switch-on time for the Heated Rear Window -Z1-. Measured value of Outside Air Temperature Sensor is evaluated by Instrument Cluster Control Module -J285- and transmitted via Comfort CAN-Bus system to the Climatronic control module -J255-. Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. Removing and Installing -- Remove the bumper cover. Refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exterior-body-panels/#body-front-roadster) . -- Disconnect connector on temperature sensor and unclip from mount in air duct
  6. Coolant Hose Connections To Heater Core Coolant hoses from connections to heater core, detaching and attaching, refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) . Heat exchanger connection in engine coolant circuit, refer to «[For engine(s) CETA, CCTA] Removal and Installation»(ref-505738-S10792382922012100100000) or to «[For engine(s) CDMA] Removal and Installation»(ref-505739-S28419895312012100100000) or to «[For engine(s) BPY] Removal and Installation»(/audi/tt/8j-2006-2010/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy-roadster) .
  7. Plenum Chamber Water Drains A water drain is installed at left and right in plenum chamber. Grommet, removing and installing, checking and cleaning, refer to «PLENUM CHAMBER WATER DRAIN, CHECKING AND CLEANING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__plenum-chamber-water-drain-checking-and) .
  8. Heated Rear Window -Z1- The command to heat the rear window is sent by the Climatronic control module -J255- via the Comfort databus system. The vehicle electrical system control module -J519- controls the rear window defogger. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function and appropriate SYSTEM WIRING DIAGRAM. Notes on function of heated rear window, refer to «REAR WINDOW DEFOGGER, CHECKING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__rear-window-defogger-checking) . Rear window, removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/windows/#glass-window-regulators-roadster)

Scheme 230

Scheme 230: A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, LEFT SIDE
Scheme 230: A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, LEFT SIDE
  1. Left Front Seat Temperature Sensor -G344- and Left Front Heated Seat -Z45- Seat heater is not installed in all vehicles (optional equipment). Seat heating, servicing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/seats/#seat-upholstery-covers-roadster) .
  2. Diagnostic Connection Perform On Board Diagnostic (OBD) on heating system using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  3. Defroster Vent/Left Side Window Removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) (Instrument Panel).
  4. Instrument Panel Vent, Left Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__instrument-panel-vents) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) (Instrument Panel).
  5. Instrument Cluster Control Module -J285- With the outside air temperature display -G106-. The Instrument Cluster Control Module -J285- evaluates the measured value of the Outside Air Temperature Sensor -G17- and then transmits it via the Comfort databus system to the Climatronic control module -J255-. Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  6. Outside Air Temperature Display -G106- The Outside Air Temperature Display is a component of the Instrument Cluster Control Module -J285-. Measured value of Outside Air Temperature Sensor -G17- is evaluated by Instrument Cluster Control Module -J285- and transmitted via Comfort CAN-Bus system to the Climatronic control module -J255-. Check using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. If temperature display is incorrect, check temperature sensor measured value using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  7. Left Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__instrument-panel-vents) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  8. Instrument Panel Vent, Center Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__instrument-panel-vents) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  9. Right Center Instrument Panel Vent Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__instrument-panel-vents) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  10. Climatronic Control Module -J255- Removing and installing, refer to «CLIMATRONIC CONTROL MODULE -J255»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__climatronic-control-module-j255) . There is no Instrument Panel Interior Temperature Sensor -G56- and no Interior Temperature Sensor Fan -V42- installed in the Climatronic control module. Also observe additional notes for Climatronic control module. Refer to «CLIMATRONIC CONTROL MODULE -J255»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__climatronic-control-module-j255) . On Board Diagnostic (OBD) of Climatronic control module -J255- is to be performed as described in Guided Fault Finding using Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. The buttons and rotatory switches have LEDs, they cannot be replaced individually. The function and indicator lights in the buttons and in the rotary knobs cannot be replaced separately.

Scheme 231

Scheme 231: A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, RIGHT SIDE
Scheme 231: A/C COMPONENTS INSIDE PASSENGER COMPARTMENT, RIGHT SIDE
  1. Dust and Pollen Filter Removing and Installing, refer to «DUST AND POLLEN FILTER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__dust-and-pollen-filter) . Follow the replacement intervals.
  2. Heater With Attachments Air duct in heater and in vehicle, refer to «AIR GUIDE IN EVAPORATOR HOUSING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-guide-in-evaporator-housing) and «AIR GUIDE IN AIR DISTRIBUTION HOUSING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-guide-in-air-distribution-housing) . Heater components, refer to «HEATER COMPONENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__heater-components) . Heater, removing and installing, refer to «A/C UNIT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__ac-unit) . NOTE: The heater should be removed in the same way as the A/C unit. Naturally, the items that affect components that are only present on the A/C system are omitted.
  3. Right Front Seat Temperature Sensor -G345- and Right Front Heated Seat -Z46- Seat heater is not installed in all vehicles (optional equipment). When the seat heater is activated, it is displayed in the Climatronic control module -J255- measured values block. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function. Seat heating, servicing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/seats/#seat-upholstery-covers-roadster) .
  4. Plug The opening on the center tunnel for draining condensation water from the A/C must be sealed with a plug if the vehicle does not have A/C.
  5. Cap Removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) . Vehicles without A/C do not have a sunlight photo sensor -G107-.
  6. Cover For Speaker In Center Instrument Panel Removing and installing cover, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  7. Light Emitting Diode for Central Locking System Removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  8. Defroster Vent/Front Window Removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  9. Defroster Vent/Right Side Window Removing and installing, refer to «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .
  10. Instrument Panel Vent, Right Removing and installing instrument panel vents, refer to «INSTRUMENT PANEL VENTS»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__instrument-panel-vents) and «Removal and Installation»(/audi/tt/8j-2006-2010/remont/exteriorinterior-trim/#interior-trim-roadster) .

HEATER COMPONENTS

Observe notes for control and regulation of components in heater. Refer to HEATER ACTIVATION AND CONTROL COMPONENTS

Note. The air duct in the heater and in the vehicle is the same as on vehicles with A/C system. Refer to AIR GUIDE IN EVAPORATOR HOUSING and AIR GUIDE IN AIR DISTRIBUTION HOUSING . The heater should be removed and installed the same way as the A/C unit. Refer to A/C UNIT .

Scheme 232

Scheme 232: HEATER COMPONENTS
Scheme 232: HEATER COMPONENTS
  1. Heater With Attachments Heater, removing and installing, refer to «A/C UNIT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__ac-unit) . NOTE: The heater should be removed in the same way as the A/C unit. Naturally, the items that affect components that are only present on the A/C system are omitted. Heater, disassembling and assembling, refer to «HEATER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__heater) .
  2. Defroster Door Motor -V107- With Defroster Door Motor Position Sensor -G135-. Lever color identification: blue. Removing and installing, refer to «DEFROSTER DOOR MOTOR -V107»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__defroster-door-motor-v107) . NOTE: This motor is fastened on the right on air distributor housing in vehicles with right-side steering.
  3. Central Air Door Motor -V70- With Central Door Motor Position Sensor -G112-. Removing and installing, refer to «CENTRAL AIR DOOR MOTOR -V70- / -V145»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__central-air-door-motor-v70) .
  4. Auxiliary Air Heater Heating Element -Z35- Only intended for vehicles with Diesel engine.
  5. Heat Exchanger For Heater Unit Removing and installing, refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) .
  6. Left Temperature Door Motor -V158- With Left Temperature Door Potentiometer/Actuator -G220-. Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE DOOR MOTOR -V158»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__left-temperature-door-motor-v158) . NOTE: On the Audi TT without A/C (heating only), only one temperature door motor is installed. Both temperature doors for the left and right sides are connected via a shaft and moved together by the Left Temperature door Motor -V158-. Vehicles without A/C do not have a temperature sensor. The outflow temperature is not controlled. The Left Temperature Door Motor is placed in a position calculated according to the temperature setting and the programmed motor stop values by the Climatronic control module -J255-.
  7. Back Pressure Door Motor -V71- With Back Pressure Door Motor Position Sensor -G113-. Removing and installing, refer to «AIR FLOW DOOR MOTOR -V71-, FUNCTION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-flow-door-motor-v71-function) .
  8. Control motor Door Motor -V113- With Recirculation Door Motor Position Sensor -G143-. Removing and installing, refer to «RECIRCULATION DOOR MOTOR -V113»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__recirculation-door-motor-v113) .
  9. Intake Housing With Recirculating Air and Air Flow/Fresh Air Door Removing and installing, refer to «AIR INTAKE HOUSING WITH RECIRCULATING AND AIR FLOW/FRESH AIR DOOR»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-intake-housing-with-recirculating-and) .
  10. Fresh Air Blower Control Module -J126- and Fresh Air Blower -V2- Removing and installing, refer to «FRESH AIR BLOWER CONTROL MODULE -J126- AND FRESH AIR BLOWER -V2»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__fresh-air-blower-control-module-j126) . The Fresh Air Blower Control Module -J126- is installed in the Fresh Air Blower -V2-. Depending on the version, both of these components can be either replaced separately or only together. Checking, refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.
  11. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__dust-and-pollen-filter) . Follow the replacement intervals.
  12. Coolant Pipes To Heater Core
  13. Grommet For sealing any holes in the refrigerant lines through the plenum chamber bulkhead to the engine compartment.

TEST REQUIREMENTS

Special tools and workshop equipment required

  1. Vehicle diagnosis, testing and information system VAS5051B (or Vehicle Diagnosis and Service System VAS 5052).
  2. A standard thermometer (for temperature measurements, if necessary a thermometer with 2 measuring probes for simultaneous measurement, for example, for temperature on the right and left)
  1. Coolant circuit has been bled according to specifications. Refer to: «[For engine(s) CETA, CCTA] Cooling System»(ref-505738-S40663187072012100100000) or to «[For engine(s) CDMA] Cooling System»(ref-505739-S08520953062012100100000) or to «[For engine(s) BPY] Cooling System»(/audi/tt/8j-2006-2010/remont/cooling-fan/#20l-cooling-system-engine-codes-bpy-roadster) General Information.
  2. All air ducts, covers and seals OK and properly installed.
  3. Air flow through dust and pollen filter not obstructed by dirt.
  4. Engine is warm.
  5. Climatronic control module -J255- DTC memory was checked and erased, basic setting was performed and Climatronic control module coding was checked using VAS5051B in "Guided Fault Finding".
  6. Adaptation of Climatronic control module was checked using VAS5051B in "Guided Fault Finding".
  7. Vehicle not exposed to sunlight.

HEATING PERFORMANCE, CHECKING

Special tools and workshop equipment required

  1. Vehicle diagnosis, testing and information system VAS5051B (or Vehicle Diagnosis and Service System VAS 5052).
  2. A standard thermometer (for temperature measurements, if necessary a thermometer with 2 measuring probes for simultaneous measurement, for example, for temperature on the right and left)

Close hood.

Close doors, windows and rear lid.

Open all dash panel vents.

Initiate heating system On Board Diagnostic (OBD) using VAS5051B in "Guided Fault Finding".

Measure the ambient temperature (temperature in workshop)

Start the engine.

Place Climatronic control module -J255- temperature knob -A- in "cold" position.

Scheme 233

Scheme 233
Scheme 233

Adjust Climatronic control module air distribution knob -C- so air flows out of instrument panel vents.

Place Climatronic control module fresh air blower speed knob -B- in "maximum fresh air blower speed" position.

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

In the "read measured values block" function, select VAS5051B in "Guided Fault Finding".

Read the measured values block with the display for the position of the Left Temperature Door Motor -V158-. Refer to VAS5051B in "Guided Fault Finding".

Measure temperature of air flowing out of left and right instrument panel vents.

Target values

  1. It will display that the Left Temperature Door Motor -V158- is at the "bottom" ("cold").
  2. The temperature of the air coming out of the left and right instrument panel vents is a maximum of 15 °C greater than the previously measured environmental temperature (the heater temperature increase is less than 16 °C).
  3. The temperature difference between the air coming out of the left and right instrument panel vents is less than 8 °C.

Place Climatronic control module -J255- temperature knob -A- in "warm" position.

Read the measured values block from Left Temperature Door Motor. Refer to VAS5051B in "Guided Fault Finding".

Measure temperature of air flowing out of left and right instrument panel vents.

Target values

  1. It will display that the Left Temperature Door Motor is at the "top" ("warm").
  2. 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).
  3. The temperature difference between the air coming out of the left and right instrument panel vents is less than 8 °C.

Note. The coolant flow rate through the heater core (and therefore the heat output) also depends on the engine speed.

Place Climatronic control module temperature knob -A- in "cold" position.

Read the measured values block with the display for the position of the Left Temperature Door Motor -V158-. Refer to VAS5051B in "Guided Fault Finding".

Measure temperature of air flowing out of left and right instrument panel vents.

Target values

  1. It will display that the Left Temperature Door Motor is at the "bottom" ("cold").
  2. The temperature of the air coming out of the left and right instrument panel vents decreases within 5 minutes to a value that is a maximum of 15 °C higher than the previously measured environmental temperature.

If the specified values are not reached, check the following

  1. If the required heat output is not reached

Ventilation of coolant circuit. Refer to [For engine(s) CETA, CCTA] General Information or to [For engine(s) CDMA] General Information or to [For engine(s) BPY] General Information .

The integration of the heater core in the coolant circuit, refer to [For engine(s) CETA, CCTA] General Information or to [For engine(s) CDMA] General Information or to [For engine(s) BPY] General Information .

Activation and function of Left Temperature Door Motor -V158- using VAS5051B in "Guided Fault Finding".

The foam seal on the heater core. Refer to HEATER CORE .

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

Coolant regulator (engine coolant may not warm properly if regulator is malfunctioning). Refer to [For engine(s) CETA, CCTA] Description and Operation or to [For engine(s) CDMA] Description and Operation or to [For engine(s) BPY] Description and Operation .

The delivery of the engine coolant pump. Refer to [For engine(s) CETA, CCTA] Description and Operation or to [For engine(s) CDMA] Description and Operation or to [For engine(s) BPY] Description and Operation .

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

Activation and function of Left Temperature Door Motor -V158- using VAS5051B in "Guided Fault Finding".

Function of temperature doors in air distribution housing. Refer to HEATER .

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

TEMPERATURE DOOR AND HEATER OUTPUT ACTIVATION, CHECKING

Note. On Audi TT without A/C (just heating), only one temperature door motor is installed. Both temperature doors for the left and right sides are connected in the heater air distributor housing via a shaft and moved together by the Left Temperature door Motor -V158-. Refer to HEATER ELECTRICAL ATTACHMENTS . Vehicles without A/C do not have a temperature sensor. The outflow temperature is not controlled. The Left Temperature Door Motor -V158- is placed in a position calculated according to the temperature setting on the temperature rotary switch -A- and the programmed motor stop values by the Climatronic control module -J255-.

  1. 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's side and front passenger's side.

Corrective action

Perform long road test at increased engine speed (at least 10 minutes, engine speed greater than 2500 RPM). Select a low gear during the test to prevent excessive vehicle speed.

If customer complains of poor heating performance at specific engine speeds, check incorporation of heater core of heater 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) CETA, CCTA] Description and Operation or to [For engine(s) CDMA] Description and Operation or to [For engine(s) BPY] Description and Operation .

  1. Heat output and temperature door activation, checking refer to «HEAT OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster) .

ELECTRICAL COMPONENTS CONTROLLED BY HEATING SYSTEM, CHECKING

From the Climatronic control module -J255

The vehicle electrical components that are activated by heater are identical to those on vehicles with A/C. The electrical test for the various components is therefore performed in the same way as the test for these components on vehicles with an A/C system. Refer to Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

These components are activated and function the same way on a vehicle without A/C (vehicles with a heater only). Refer to COMPONENTS ACTUATED BY A/C SYSTEM, ELECTRICAL TEST and Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

Note. Various vehicle electrical components (for example, Heated Rear Window -Z1- and heated seats) that do not belong to the heater are activated by the Climatronic control module -J255-. Check the electrical components as described in Guided Fault Finding (it is the same on both vehicle with and without A/C). Refer to COMPONENTS ACTUATED BY A/C SYSTEM, ELECTRICAL TEST and Vehicle diagnosis, testing and information system VAS5051B in the "Guided Fault Finding" function.

HEATER ELECTRICAL ATTACHMENTS

Heater, removing and installing, refer to A/C UNIT .

Note. Remove the heater the same way as removing the A/C unit. The items that affect components that are only present on the A/C system are omitted.

Scheme 234

Scheme 234: HEATER ELECTRICAL ATTACHMENTS
Scheme 234: HEATER ELECTRICAL ATTACHMENTS
  1. Wiring Harness For Heater Mark the allocation before disconnecting the connectors (connectors of same shape for different motors, risk of interchanging them). 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. Heater Unit Removing and installing, refer to «A/C UNIT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__ac-unit) (A/C unit, removing and installing). NOTE: Remove the heater the same way as removing the A/C unit. The items that affect components that are only present on the A/C system are omitted. Heater, disassembling and assembling, refer to «HEATER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__heater) . Air guide channel, disassembling and assembling, refer to «AIR GUIDE CHANNEL»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__air-guide-channel) .
  3. Auxiliary Air Heater Heating Element -Z35- Only intended for vehicles with Diesel engine.
  4. Cover For Coolant Pipes and Heater Core This illustration shows version for vehicles with Auxiliary Air Heater Heating Element -Z35-.
  5. Screw
  6. Central Air Door Motor -V70- With Central Door Motor Position Sensor -G112-. Removing and installing, refer to «CENTRAL AIR DOOR MOTOR -V70- / -V145»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__central-air-door-motor-v70) .
  7. Left Temperature Door Motor -V158- With Left Temperature Door Potentiometer/Actuator -G220-. Lever color identification: white. Removing and installing, refer to «LEFT TEMPERATURE DOOR MOTOR -V158»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__left-temperature-door-motor-v158) . NOTE: On the Audi TT with A/C (heating only), only one temperature door motor is installed. Both temperature doors for the left and right sides are connected via a shaft and moved together by the Left Temperature door Motor -V158-. Vehicles without A/C do not have a temperature sensor. The outflow temperature is not controlled. The Left Temperature Door Motor -V158- is placed in a position calculated according to the temperature setting and the programmed motor stop values by the Climatronic control module -J255-.
  8. Connecting Rod to Left Temperature Door Motor -V158- Color identification: black.
  9. Defroster Door Motor -V107- With Defroster Door Motor Position Sensor -G135-. Lever color identification: blue. Removing and Installing, refer to «DEFROSTER DOOR MOTOR -V107»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__defroster-door-motor-v107) . NOTE: This motor is fastened on the right on air distributor housing in vehicles with right-side steering.
  10. Connecting Rod to Defroster Door Motor -V107- Color identification: blue.
  11. Cover and Bracket for Air Flow Door Motor -V71- and Recirculation Door Motor -V113- Removing and installing, refer to «AIR FLOW DOOR MOTOR -V71-, FUNCTION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-flow-door-motor-v71-function) . After installing, check both control motors which must be held in position by this bracket, if they are not installed free of play, use some foam to rectify play if necessary, attaching it to inside of mounting points of bracket. Refer to «AIR FLOW DOOR MOTOR -V71-, FUNCTION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-flow-door-motor-v71-function) .
  12. Control motor Door Motor -V113- With Recirculation Door Motor Position Sensor -G143-. Removing and installing, refer to «AIR FLOW DOOR MOTOR -V71-, FUNCTION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-flow-door-motor-v71-function) .
  13. Back Pressure Door Motor -V71- With Back Pressure Door Motor Position Sensor -G113-. Removing and installing, refer to «AIR FLOW DOOR MOTOR -V71-, FUNCTION»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-flow-door-motor-v71-function) .
  14. Foam Seal For sealing heater air intake shroud to vehicle.
  15. Intake Housing With Recirculating Air and Air Flow/Fresh Air Door Do not disassemble further. Removing and installing, refer to «AIR INTAKE HOUSING WITH RECIRCULATING AND AIR FLOW/FRESH AIR DOOR»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-intake-housing-with-recirculating-and) . Can be obtained as a replacement part in various versions. Refer to «AIR INTAKE HOUSING WITH RECIRCULATING AND AIR FLOW/FRESH AIR DOOR»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-intake-housing-with-recirculating-and) .
  16. Fresh Air Blower Control Module -J126- and Fresh Air Blower -V2- Removing and installing, refer to «FRESH AIR BLOWER CONTROL MODULE -J126- AND FRESH AIR BLOWER -V2»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__fresh-air-blower-control-module-j126) . The Fresh Air Blower Control Module -J126- is installed in the Fresh Air Blower -V2-. Depending on the version, both of these components can be either replaced separately or only together.
  17. Insulation Mat
  18. Screw Clips
  19. Cable Ties
  20. Wiring Harness Bracket

HEATER

Note. Remove the heater the same way as removing the A/C unit. The items that affect components that are only present on the A/C system are omitted.

Remove heater. Refer to A/C UNIT .

Remove electrical attachments from heater. Refer to HEATER ELECTRICAL ATTACHMENTS .

Scheme 235

Scheme 235: HEATER
Scheme 235: HEATER
  1. Air Distribution Housing For Heater
  2. Screw
  3. Air Guide Channel To Left Footwell Vent "Heater" version (without an opening for installing a temperature sensor).
  4. Heater Core For Heater Unit Removing and installing, refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) .
  5. Sealing Ring Replace Coat thinly with coolant and insert on proper side. Refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) .
  6. Clip Replace Ensure it is seated correctly. Removing and installing, refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) .
  7. Screw Tightening specification 2.5 Nm
  8. Coolant Pipes Disconnect and connect from heater core. Refer to «HEATER CORE»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__heater-core) .
  9. Foam Spacer Installed between grommet and heater.
  10. Grommet Install in the back of the plenum chamber before installing the heater, refer to «A/C UNIT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__ac-unit) . Installing, refer to «A/C UNIT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__ac-unit) .
  11. Air Guide Channel Air guide channel, disassembling and assembling, refer to «AIR GUIDE CHANNEL»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#heating-ventilation-roadster__air-guide-channel) .
  12. Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__dust-and-pollen-filter) . Follow the replacement intervals.
  13. Cover For Dust and Pollen Filter Removing and installing, refer to «DUST AND POLLEN FILTER»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__dust-and-pollen-filter) .
  14. Air Guide Channel To Right Footwell Vent "Heater" version (without an opening for installing a temperature sensor).
  15. Plug Present two times in different version. Refer to «AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT»(/audi/tt/8j-2006-2010/remont/automatic-hvac-system/#air-conditioning-roadster__air-routing-and-distribution-in-passenger) .

AIR GUIDE CHANNEL

Note. Remove the heater the same way as removing the A/C unit. The items that affect components that are only present on the A/C system are omitted.

Remove heater. Refer to A/C UNIT .

Remove electrical attachments from heater. Refer to HEATER ELECTRICAL ATTACHMENTS .

Disassemble heater as far as necessary. Refer to HEATER .

Scheme 236

Scheme 236: AIR GUIDE CHANNEL
Scheme 236: AIR GUIDE CHANNEL
  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

See also:
• [For transmission(s) 02E] Removal and Installation
• CHECKING ELECTRICAL COMPONENTS
• PASSENGER COMPARTMENT FORCED AIR EXTRACTION, CHECKING
• FRESH AIR INTAKE COVER
• Removal and Installation
• [For engine(s) BPY] Description and Operation
• HEATER CORE
• PLENUM CHAMBER WATER DRAIN, CHECKING AND CLEANING
• REAR WINDOW DEFOGGER, CHECKING
• Removal and Installation
• Removal and Installation
• Removal and Installation
• INSTRUMENT PANEL VENTS
• CLIMATRONIC CONTROL MODULE -J255
• DUST AND POLLEN FILTER
• AIR GUIDE IN EVAPORATOR HOUSING
• AIR GUIDE IN AIR DISTRIBUTION HOUSING
• A/C UNIT
• DEFROSTER DOOR MOTOR -V107
• CENTRAL AIR DOOR MOTOR -V70- / -V145
• LEFT TEMPERATURE DOOR MOTOR -V158
• AIR FLOW DOOR MOTOR -V71-, FUNCTION
• RECIRCULATION DOOR MOTOR -V113
• AIR INTAKE HOUSING WITH RECIRCULATING AND AIR FLOW/FRESH AIR DOOR
• FRESH AIR BLOWER CONTROL MODULE -J126- AND FRESH AIR BLOWER -V2
• COMPONENTS ACTUATED BY A/C SYSTEM, ELECTRICAL TEST
• AIR ROUTING AND DISTRIBUTION IN PASSENGER COMPARTMENT
• CONTACT CORROSION
• PERFORMING GUIDED FAULT FINDING ON HEATING SYSTEM
• HEATING SYSTEM ELECTRICAL COMPONENTS
• ELECTRICAL COMPONENTS CONTROLLED BY HEATING SYSTEM, CHECKING
• COMPONENTS OUTSIDE PASSENGER COMPARTMENT
• HEATER COMPONENTS
• HEATER ACTIVATION AND CONTROL COMPONENTS
• HEATER
• HEATER ELECTRICAL ATTACHMENTS
• AIR GUIDE CHANNEL

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