Heating Output And Temperature Door Activation, Testing Requirements

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Installed on vehicles with high voltage systems (hybrid vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system, refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS and SAFETY PRECAUTIONS WHEN WORKING ON HIGH VOLTAGE VEHICLES .

If it is necessary for the following procedure to perform work in the vicinity of high voltage components, "perform a visual inspection of the high voltage components and cables for damages" and "always follow the warnings when working on the high voltage system", refer to SAFETY PRECAUTIONS WHEN WORKING ON HIGH VOLTAGE VEHICLES .

WARNING:

Risk of unintended engine start

The ignition must be turned off and the ignition key must remain outside of the vehicle when working on vehicles with a high voltage system.

WARNING:

Handling high voltage cables:

Do not stand on or place tools on high voltage cables and their components as it may damage the cable insulation.
Never bend or kink high voltage cables forcefully as it may damage the cable insulation.
The round high voltage connectors are color coded with an external color ring and are mechanically coded using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid any mechanical damage to the high voltage connector.

CAUTION:

There is a risk of electrocution from damaged high voltage components.

Observe the following when working around high voltage components and high voltage wires:

Never work around high voltage components and cables with cutting, deformed, or sharp edged tools, or heat sources such as welding or soldering tools, heated air, and thermal glue.
Inspect the high voltage components visually before beginning.
Perform a visual inspection of the Electric Drive Power and Control Electronics -JX1-, the Electro-Drive Drive Motor -V141-, the Electrical Air Conditioning (A/C) compressor -V470- and the high voltage lines when working in the engine compartment.
Perform a visual inspection of the high voltage lines and covers when working on the underbody.
Perform a visual inspection of the high voltage lines and the Electrobox with the High Voltage System Maintenance Connector -TW- when working in the luggage compartment.
Perform a visual inspection on all of the potential equalization cables.

Observe the following items when performing the visual inspection:

The components do not display any signs of external damage.
The high voltage cable insulation and the potential equalization cables are not damaged.
The high voltage cables do not display any abnormal deformations.
Every high voltage component is marked with a red warning label.

Working on a high voltage system when activated or with the ignition turned on

CAUTION:

The engine may start unexpectedly when performing work while the ignition is turned on or when the ready mode is activated and may cause poisoning in enclosed spaces. Be aware of body limbs and/or clothing when clamping or pulling.

Perform the following steps before turning on the ignition:

Move the selector lever into position P.
Activate the parking brake.
Switch off ignition.
Open the engine hood.
Connect the charging unit for example Battery Charger :VAS5095A to the battery jump start terminal for the 12V vehicle electrical system
Switch on the ignition.

-- Charge the vehicle battery, for example, using the Battery Charger:VAS5904 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active, refer to [FOR ENGINE(S) CTUB, CEJA, CGTA, CDRA, CEUA, CPNA] BATTERY, CHARGING and SAFETY PRECAUTIONS WHEN WORKING ON HIGH VOLTAGE VEHICLES .

-- Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.

NOTE:

Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active.

The ready mode is displayed in the Instrument Cluster Control Module -J285- above the "power meter", refer to the Owners Manual.

Activate and deactivate the ready mode, refer to the Owners Manual (consult the display in the Instrument Cluster Control Module -J285-).

All Vehicles

The coolant circuit is bled according to specifications, refer to COOLANT, DRAINING AND FILLING (CDTA, CDTB, CLAB, CMHA, CPNA, CTBA, CTBB, CDTC, CPNB, CTBD) , COOLANT, DRAINING AND FILLING (CEJA, CTNA) , COOLANT, DRAINING AND FILLING (CEUA, CGTA, CTFA, CTGA, CTGF, DDTA)
The engine is warm (the coolant temperature is higher than 80 °C (176 °F)).
Radiator and condenser are clean (if necessary clean).
All air ducts, covers and seals are OK and properly installed.
Air flow through dust and pollen filter not obstructed by dirt, refer to DUST AND POLLEN FILTER, REMOVING AND INSTALLING .
The air intake for the front Air Conditioning (A/C) unit (in fresh air and recirculation mode) is not impaired by contamination or subsequently installed components.
Ensure that the air outlet from the rear footwell vents (under the front seats) is not blocked by the floor mats or other objects.
The air duct for glove compartment cooling is installed in the glove compartment as specified, refer to AIR DUCT FOR GLOVE COMPARTMENT COOLING, REMOVING AND INSTALLING .
The vehicle is not exposed to sunlight.
The event memory of the front A/C display control head, the Climatronic Control Module -J255- (and the Rear A/C Display Control Head -E265- if present) was checked and erased, the basic setting was performed, and the coding of the Climatronic Control Module -J255- (and the Rear A/C Display Control Head -E265- if present) was checked see Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
The adaptation of the Climatronic Control Module -J255- (and the Rear A/C Display Control Head -E265-, if present) was checked, refer to Vehicle Diagnostic Tester in the "Guided Fault Finding " Function.
The following is set in the Multi Media Interface (MMI) via the "A/C" function in the "car" / "car systems" menu for the regulation of the A/C system: automatic recirculation "off", air flow "center" and footwell temperature "medium" (arrow pointing up).

NOTE:

The various functions for setting the A/C system in the MMI (function "A/C" in the "Car" / "Car-System" menu) differ depending on the A/C system version, on the time period of production and on the vehicle version (and may not be available for all versions), refer to the Vehicle Operating Instructions.

Certain settings for the A/C system via the MMI are no longer planned from a specific date of manufacture (for example, the "Air still" function), refer to the Vehicle Operating Instructions. Also pay attention to the coding and adaptation of the Climatronic Control Module -J255- front A/C display and control head, refer to Vehicle Diagnostic Tester in the "Guided Fault Finding " Function

All instrument panel vents, the B-pillar vents, and the vents in the rear center console are open.
The hood is closed.

Installed on Vehicles with High Voltage Systems (Hybrid Vehicles)

The ignition is turned on and the ready mode is active, the engine runs or starts only, when heated refrigerant is necessary to reach the temperature setting in the vehicle interior or for example the Traction Battery -A2- (hybrid battery) has not been charged enough.
With the ignition turned on and the temperature preset at "warm" on the Climatronic Control Module -J255- A/C display and control head (display "HI" in the A/C system display and control head), the coolant flow through the heat exchanger is maintained via the Coolant Recirculation Pump -V50-, refer to OVERVIEW - ELECTRIC COOLANT PUMP .

CAUTION:

Perform the following steps before turning on the ignition:

Move the selector lever into position P.
Activate the parking brake.
Switch off ignition.
Open the engine hood.
Connect the charging unit for example Battery Charger:VAS5095A to the battery jump start terminal for the 12V vehicle electrical system
Switch on the ignition.

When the engine is running (drive ready mode is active for vehicles with a high voltage system) and the temperature selection is on "warm" on the Climatronic Control Module -J255- A/C system display control head and the Rear A/C Display Control Head -E265- (display "HI" in the display for the A/C system control head and the Multi Media Interface).

Vehicles without A High Voltage System

Engine is running.
While the engine is running and the temperature is set at "warm" on the Climatronic Control Module -J255- (the indicator in the display is "HI" for the driver and front passenger on the Climatronic Control Module -J255- and on the Rear A/C Display Control Head -E265-, if applicable).

All Vehicles

While the engine is running (ready mode is active on vehicles with a high voltage system) and the temperature is set to "warm" (indicator "HI") on the Climatronic Control Module -J255- (and on the Rear A/C Display Control Head -E265-) and in the MMI display.

-- The Coolant Shut-Off Valve -N82- is not activated.

-- On vehicles with a regulated coolant circuit (only installed in certain engines from MY 2010), the activation and function of these components are OK (for example, a regulated coolant pump and Cylinder Head Coolant Valve -N489-), refer to[FOR ENGINE(S) CPNA] COOLANT HOSE CONNECTION DIAGRAM .

NOTE:

On vehicles with an engine with a regulated coolant circuit (for example, with a regulated coolant pump and a Cylinder Head Coolant Valve -N489-), no Coolant Shut-Off Valve -N82- is currently being installed. On an engine with a regulated coolant pump, the engine control module activates the coolant pump, and in doing so regulates the coolant circuit, refer to [FOR ENGINE(S) CPNA] COOLANT HOSE CONNECTION DIAGRAM .

-- The Heater Coolant Shut-Off Valve -N279- is not activated for vehicles with an auxiliary heater.

-- The Coolant Recirculation Pump -V50- is activated.

-- The Recirculation Pump -V55- is activated for vehicles with an auxiliary heater.

NOTE:

If in vehicles with a Coolant Shut-Off Valve -N82- (not installed in all vehicles) or with a Heater Coolant Shut-Off Valve -N279- this component is activated, the passenger compartment is not heated, refer to COOLANT SHUT-OFF VALVE -N82-, FUNCTION and see Vehicle Diagnostic Tester in the "Guided Fault Finding " function.

If the Coolant Shut-Off Valve -N82- /Heater Coolant Shut-Off Valve -N279- does not open completely in the inactivated state, there may be a complaint regarding a lack of heating output.

When testing the heating output, it is helpful to display the following measured values of the Climatronic Control Module -J255- :

The measured values of the following temperature sensors (Left Vent Temperature Sensor -G150-, Right Vent Temperature Sensor -G151-, Left Footwell Vent Temperature Sensor -G261-, Right Footwell Vent Temperature Sensor -G262-, Evaporator Vent Temperature Sensor -G263-).
The measured value of the Rear Intake Air Temperature Sensor -G639- (only for a vehicle without a rear A/C unit, with and without a Rear A/C Display Control Head -E265-)
The activation of the following components (Fresh Air Blower -V2-, Rear Fresh Air Blower -V80-, Coolant Fan -V7-, Coolant Fan 2 -V177-).
The activation of the following components (if present, depending on the equipment and engine type Coolant Recirculation Pump -V50- /Recirculation Pump -V55-, Coolant Shut-Off Valve -N82- /Heater Coolant Shut-Off Valve -N279-).
The activation of the Air Conditioning (A/C) Compressor Regulator Valve -N280- (compressor switch off controls and Air Conditioning (A/C) compressor actual current) for vehicles without a high voltage system.
The activation of the Electrical Air Conditioning (A/C) Compressor -V470- (compressor switch off controls and A/C compressor speed) for vehicles with a high voltage system.
The coolant temperature and the ambient temperature.
The measured value of the A/C Pressure/Temperature Sensor -G395- (coolant pressure).

NOTE:

For vehicles on which there is also a Rear A/C Display Control Head -E265- installed for the version with the rear air distribution housing (for example on the Audi A8 hybrid and from MY 2013 for certain markets). The air temperature and volume calculated and regulated by the Climatronic Control Module -J255- is also influenced by the setting on the Rear A/C Display Control Head -E265-. However, the temperature only is adjustable for the Rear A/C Display Control Head -E265- and there is only an AUTO button, refer to REAR A/C DISPLAY CONTROL HEAD -E265-, REMOVING AND INSTALLING .

Checking

Set the following on the front A/C display control head, the Climatronic Control Module -J255- :

"Auto" mode (the indicator lamps in both AUTO buttons illuminate).
Temperature preselect "cold" for the driver's and passenger's side (display "LO" for the driver's and passenger's die in the A/C Control Head display and in the MMI display).
A/C compressor is turned on (the indicator lamp in the AC or A/C button turns on).
Preselection for the fresh air blower (the Fresh Air Blower -V2- and the Rear Fresh Air Blower -V80-) "maximum speed" (shown in the display of the Climatronic Control Module -J255- and in the display of the Multi Media Interface (MMI) speed "10" or higher).

Set the following on the Rear A/C Display Control Head -E265- if present:

"Auto" mode (the indicator lamps in one or both AUTO buttons illuminate).
Temperature preselection "cold" (display "LO" for the left and right sides).
Preselection for the Rear Fresh Air Blower -V80- "maximum speed".

NOTE:

The indicator lamps in the AUTO buttons for the Climatronic Control Module -J255- / Rear A/C Display Control Head -E265- go out when the fresh air blower speed is changed manually.

The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)

-- Check that for vehicles with the diesel engine and for vehicles with the high voltage system (hybrid vehicles with gasoline engines), the activation and functionality of the auxiliary heater is OK.

NOTE:

The type of auxiliary heating depends on the vehicle equipment level. In vehicles with a diesel engine without a "parking heater" as optional equipment, an Auxiliary Air Heater Control Module -J604- with an Auxiliary Heater Heating Element -Z35- is installed. In vehicles with a "parking heater" as optional equipment, the Auxiliary Air Heater Control Module -J604- with the Auxiliary Heater Heating Element -Z35- is omitted and the parking heater is activated as the auxiliary heater, refer to AUXILIARY HEATER, TESTING .

For vehicles with a high voltage system (hybrid vehicles with a gasoline engine) there is an Auxiliary Air Heater Control Module -J604- with a Auxiliary Heater Heating Element -Z35- installed, refer to AUXILIARY HEATER, TESTING .

Certain A/C system functions can be switched on and off via the MMI under the "A/C system" function in the "car" / "car systems" menu. The A/C system control can also be influenced via presettings in the MMI under the "A/C system" function in the "car" / "car systems" menu. Therefore, first check the presetting in the MMI in the case of a problem with these components, refer to Infotainment/MMI Operating Instructions.

Functions While the Engine Is Running (Non-Hybrid Vehicles) / Drive Ready Mode Activated (Hybrid Vehicles):

NOTE:

On vehicles with a high voltage system (hybrid vehicles) and on vehicles with the start stop system, the engine only runs when an additional heat output is needed to reach the set temperature.

-- The coolant fan(s) (Coolant Fan -V7- and Coolant Fan 2 -V177-) run (activation and speed depend on refrigerant circuit pressure and engine temperature).

NOTE:

Depending on the version of the front A/C display control head, the Climatronic Control Module -J255-, the coolant fan(s) (Coolant Fan -V7- and Coolant Fan 2 -V177-) are only switched on starting at a certain pressure in the coolant circuit (currently starting at a pressure of approximately 9 bar (130 psi)). The activation of the coolant fan(s) is displayed in the "read measured values" function of the "Guided Fault Finding ", refer to Vehicle Diagnostic Tester in the "Guided Fault Finding " function.

-- The Fresh Air Blower -V2- runs with maximum speed ("10" or greater).

-- The Rear Fresh Air Blower -V80- runs at maximum speed.

NOTE:

The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)

-- The front A/C system switches to recirculation mode. Approximately one minute after the vehicle is started, the back pressure/fresh air door is closed and the recirculation door is opened. The Fresh Air Blower -V2- extracts the air from the passenger compartment below the instrument panel/glove compartment.

NOTE:

If one of these requirements are not fulfilled, check the Diagnostic Trouble Code (DTC) memory, perform the output diagnostic test mode and read out the relevant measured value, refer to Vehicle Diagnostic Tester.

If the above mentioned requirements are fulfilled:

For heating output and activation of the temperature doors, refer to HEAT OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING .