Heating Output And Temperature Control Door Activation, Checking, Vehicles With Manual Climate Control System

WARNING: This page is about a different variant/trim than selected.

Refer to HEAT OUTPUT TEST INFORMATION AND TOOLS REQUIRED

Test Requirements

Coolant circuit bled according to specifications. Refer to COOLANT, DRAINING AND FILLING [DAZA] / COOLANT, DRAINING AND FILLING [CNTC, CYFB] .
All air ducts, covers and seals are OK and properly installed.
Seal between engine compartment, hood and plenum chamber is OK and installed correctly. Refer to Bulkhead ; (Overview - Plenum Chamber Cover) to check.
If installed: After-Run Coolant Pump -V51- and Coolant Shut-Off Valve -N82- function is OK.
The airflow through the dust and pollen filter is not obstructed by dirt. Refer to DUST AND POLLEN FILTER, REMOVING AND INSTALLING to check.
The air intake of the heater and A/C unit (in fresh air and recirculating air modes) is not obstructed by dirt or retrofitted components.
The vehicle is not exposed to sunlight.
The A/C system cooling output was checked and is OK. Refer to COOLING OUTPUT, CHECKING, VEHICLES WITH MANUAL CLIMATE CONTROL SYSTEM .
Engine is warm: Coolant temperature is greater than 80 °C (176 °F).
The DTC memory for the Climatronic Control Module -J255- was checked and erased and the basic setting was performed using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.
The coding and adaptation of the Climatronic Control Module -J255- was checked using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.
Vehicles with TDI engine: Activation and function of the Auxiliary Heater Heating Element -Z35- is OK. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Engine Control Module -J623-).
Vehicles with a gasoline engine and an Auxiliary Heater Heating Element -Z35- (introduction not yet finalized): Activation and function of the Auxiliary Heater Heating Element -Z35- is OK. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.

Checking

-- Close the hood, doors, windows and sliding sunroof.

-- Open all instrument panel vents.

-- Start the engine and adjust the following settings on the control heads:

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NOTE:

This illustration shows the layout of the regulators -1, 2 and 3- and the buttons -4 and 5- on a left-hand drive vehicle. The layout may be different on right-hand drive vehicles.

Turn the regulator -1- (Front A/C Display Control Head 2 -E775-) for the fresh air blower to the maximum speed.
Turn the regulator -2- (Front A/C Display Control Head 3 -E776-) for the temperature setting to the "cold" stop.
Turn the regulator -3- (Front A/C Display Control Head 4 -E777-) for air distribution to "instrument panel vent".
A/C compressor on: The indicator lamp in the A/C button (in regulator -2-) illuminates.
Recirculating air mode off: The indicator lamp in the Fresh Air and Recirculating Air Mode Button -E781- -4- does not come on.

-- Let the A/C system run for several minutes at maximum cooling output with the engine running.

-- Measure the temperature of the air coming out of the left and right instrument panel vents with a thermometer.

-- Compare the measured values with the displayed measured value for the Evaporator Vent Temperature Sensor -G263-. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Climatronic Control Module -J255-).

Specified Values:

The measured values for the air temperature from the left and right vents must not be lower than the measured value of the Evaporator Vent Temperature Sensor -G263- and also not greater than a maximum of 7 °C (45 °F) after five minutes. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.
The deviation of the measured air temperatures from the left and right vents is less than 8 °C (46 °F).

If the specified values are not reached, check the following:

Activation and function of the Temperature Control Door Motor -V68- using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Climatronic Control Module -J255-).
Function of the temperature control door in the heater and A/C unit. Refer to AIR DISTRIBUTION HOUSING, REMOVING AND INSTALLING .
Foam seal on the heater core for the heater. Refer to HEATER CORE, REMOVING AND INSTALLING .

-- Set the highest possible temperature.

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Turn the regulator -2- (Front A/C Display Control Head 3 -E776-) for the temperature setting to the "warm" stop.

-- Measure the temperature of the air coming out of the left -1- and right -2- instrument panel vents with a thermometer.

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Specified values with an engine temperature of approximately 90 °C (194 °F):

The temperature of the air from the instrument panel vents goes above 55 °C (131 °F).
The temperature deviation between the left and right side is less than 8 °C (46 °F).

If the specified values are not reached, check the following:

Coolant circuit bleeding. Refer to COOLANT, DRAINING AND FILLING [DAZA] / COOLANT, DRAINING AND FILLING [CNTC, CYFB] .
Incorporation of the heater core for the heater in the coolant circuit. Refer to COOLANT SYSTEM/COOLANT [DAZA] / COOLANT SYSTEM/COOLANT [CNTC, CYFB] (Connection Diagram for Coolant Hoses).
Foam seal on the heater core for the heater. Refer to HEATER CORE, REMOVING AND INSTALLING .
Activation and function of the Temperature Control Door Motor -V68- using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Climatronic Control Module -J255-).
Function of the temperature control door in the heater and A/C unit. Refer to AIR DISTRIBUTION HOUSING, REMOVING AND INSTALLING .
Engine coolant thermostat. The engine coolant may not heat properly if the coolant thermostat is faulty. Refer to COOLANT PUMP/COOLANT THERMOSTAT [DAZA] / COOLANT PUMP/COOLANT THERMOSTAT [CNTC, CYFB] (Coolant Thermostat, Checking).
Engine coolant pump. Refer to COOLANT PUMP/COOLANT THERMOSTAT [DAZA] / COOLANT PUMP/COOLANT THERMOSTAT [CNTC, CYFB] (Overview - Coolant Pump).
If installed: Check the function of the After-Run Coolant Pump -V51- and the Coolant Shut-Off Valve -N82-. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Engine Control Module -J623-).

NOTE:

For vehicles without an After-Run Coolant Pump -V51-, set the engine speed to approximately 2000 RPM and repeat the test if necessary. If the air temperature goes above 55 °C (131 °F) when repeating the test at a higher engine speed, this indicates that there is too little coolant flowing through the heater core for the heater. Cause: The delivery quantity of the engine coolant pump is too low at idle speed, or the incorporation of the heater core for the heater in the coolant circuit is not according to the specification. Refer to COOLANT SYSTEM/COOLANT [DAZA] / COOLANT SYSTEM/COOLANT [CNTC, CYFB] (Connection Diagram for Coolant Hoses).

If too little warmed up coolant flows through the heater core for the heater, the required heat output is not reached.

-- Set the lowest possible temperature.

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Turn the regulator -2- (Front A/C Display Control Head 3 -E776-) for the temperature setting to the "cold" stop.

-- Measure the temperature of the air coming out of the left -1- and right -2- instrument panel vents with a thermometer.

Courtesy of AUDI OF AMERICA, LLC

Specified Values:

The measured values must not be smaller than the measured value of the Evaporator Vent Temperature Sensor -G263- and also not greater than a maximum of 7 °C (45 °F) after five minutes. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.
The deviation of the measured air temperatures from the left and right vents is less than 8 °C (46 °F).

If the specified values are not reached, check the following:

Activation and function of the Temperature Control Door Motor -V68- using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function (for the Climatronic Control Module -J255-).
Function of the temperature control door in the heater and A/C unit. Refer to AIR DISTRIBUTION HOUSING, REMOVING AND INSTALLING .
Foam seal on the heater core for the heater. Refer to HEATER CORE, REMOVING AND INSTALLING .