Heating Output And Temperature Door Activation, Testing Requirements
For vehicles with a high-voltage system (hybrid vehicles and Audi A6 e-tron)
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 .
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" (Refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS .) and "always follow the warnings when working on the high voltage system." .
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.
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 the high voltage connector.
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 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
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 BATTERY, CHARGING and Warnings And Safety Precautions .
-- 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.
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 appropriate service/repair/system information.
Activate and deactivate the ready mode. Refer to the appropriate service/repair/system information. (consult the display in the Instrument Cluster Control Module -J285-).
Also for the Audi A6 e-tron
-- The DTC memory for the Thermal Management Control Module -J1024- was checked and erased using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
There are other components installed in the engine coolant circuit on the Audi A6 e-tron (High-Voltage Heater (PTC) -Z115-, Thermal Management Coolant Pump 2 -V618- etc.). These components (that are activated and monitored by the Thermal Management Control Module -J1024-) ensure that there is also a sufficient amount of heat available for heating the vehicle interior in electric drive mode. Refer to A/C SYSTEM, INTEGRATING INTO HIGH-VOLTAGE SYSTEM COOLANT CIRCUIT (ONLY AUDI A6 E-TRON) .
All Vehicles
- The coolant circuit is bled according to specifications.
- 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 apparatus for the A/C unit (in fresh air and recirculating air mode) is not impaired by soiling or components installed as retrofit.
- Ensure that the air outlet from the rear footwell vents (under the front seats) is not blocked by floor mats or other objects.
- The air duct to the glove compartment cooling is installed according to specification on the "Comfort" A/C system version. Refer to AIR GUIDE FOR GLOVE COMPARTMENT COOLING, REMOVING AND INSTALLING (for A/C systems with the "Basic" version, the connection for the glove compartment cooling is sealed).
- The vehicle is not exposed to sunlight.
- The Diagnostic Trouble Code (DTC) memory for the Climatronic Control Module -J255- control head (and for the Rear A/C Display Control Head -E265-) are checked and erased, the basic setting is performed and the coding for the Climatronic Control Module -J255- (and if equipped the Rear A/C Display Control Head -E265-) are checked. Use the 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.
- For vehicles with the "Basic" A/C system version: The following is set in the MMI (Multi Media Interface) via the "A/C" function in the "car" / "car systems" menu for the regulation of the A/C system (if possible): Air flow "center".
- For vehicles with the "Comfort" A/C system version: The following is set in the MMI (Multi Media Interface) 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).
The various functions for the adjustment of the A/C system in the MMI (Multi Media Interface) (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 (not available for all versions). Refer to the Vehicle Operating Instructions.
Currently no setting via the MMI is intended for vehicles in the USA version with the "Basic" A/C system. Refer to the Vehicle Operating Instructions.
- Open all instrument panel vents and the vents in the rear center console.
- Open the vents in the B-pillars on the "Comfort" version.
- The hood is closed.
For Vehicles With A High-Voltage System (Hybrid Vehicles And Audi A6 E-Tron)
- The ignition is turned on and the ready mode is active, the engine starts or only runs when warmer coolant is necessary to reach the temperature setting in the passenger compartment or, for example, the Traction Battery -A2- (hybrid battery) has not been charged enough.
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.
When the ignition is turned on and the temperature preset is "warm" on the Climatronic Control Module -J255- A/C system control head ("HI" is displayed in the A/C system control head and the MMI), the following components (if equipped) are activated. Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, TESTING REQUIREMENTS .
Vehicles without High-Voltage System
- Engine is running.
- With the engine running and the temperature preset at "warm" on the Climatronic Control Module -J255- (for example, "HI" is displayed for an "Convenience" A/C system version for the driver and front passenger side on the Climatronic Control Module -J255- and the Rear A/C Display Control Head -E265-), the following components (if equipped) are activated. Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, TESTING REQUIREMENTS .
All Vehicles
- 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 A/C system Climatronic Control Module -J255- control head (display "HI" is displayed in the A/C system control head and the MMI), the following components (if equipped) are activated.
-- The Coolant Shut-Off Valve -N82- is not activated.
-- 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.
Also For The Audi A6 E-Tron
-- The Thermal Management Coolant Pump 2 -V618- is activated.
-- Depending on the coolant and ambient temperature, the High-Voltage Heater (PTC) -Z115- is activated.
-- Depending on the coolant and ambient temperature, the Coolant Change-Over Valve 3 -N634- is activated.
The function of the High-Voltage Heater (PTC) -Z115-, the Coolant Change-Over Valve 3 -N634- and the Thermal Management Coolant Pump 2 -V618- can be checked, for example, by activating via the Thermal Management Control Module -J1024- and checking the Thermal Management Coolant Temperature Sensor 2 - G903- and Thermal Management Coolant Temperature Sensor 7 -G908- using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
The Coolant Change-Over Valve 3 -N634- is activated when the coolant temperature in the engine is less than a specific value. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
The Coolant Change-Over Valve 3 -N634- is the equivalent to the Heater Coolant Shut-Off Valve -N279- in design and function for vehicles with a parking heater.
If the Coolant Change-Over Valve 3 -N634- does not close completely when it is activated, there may be a complaint regarding a lack of heating output.
All Vehicles
If the Coolant Shut-Off Valve -N82- / Heater Coolant Shut-Off Valve -N279- is activated, the heating of the vehicle interior does not take place. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function. Refer to Coolant Shut-Off Valve -N82-, FUNCTION (Coolant Shut-Off Valve -N82-). Refer to Heater Coolant Shut-Off Valve -N279-, FUNCTION (Heater Coolant Shut-Off Valve -N279-).
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.
The Rear Temperature Selection Potentiometer -G538- is set to "warm", if applicable. The Rear Temperature Selection Potentiometer -G538- is installed only for vehicles with the "Basic" A/C system version in market specific versions in the rear center console.
When testing the heating output, it is helpful to display the following measured values of the Climatronic Control Module -J255- :
- Measured values for 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 activation of the following components Fresh Air Blower -V2-, Coolant Fan -V7-, and Coolant Fan 2 -V177-.
- Activation of the following components, if applicable: Coolant Recirculation Pump -V50-, Coolant Shut-Off Valve -N82-.
- On the Audi A6 e-tron, the activation and measured values of the following components: Thermal Management Coolant Pump 2 -V618-, High-Voltage Heater (PTC) -Z115-, Thermal Management Coolant Temperature Sensor 2 -G903-, Thermal Management Coolant Temperature Sensor 7 -G908- (always in the Thermal Management Control Module -J1024-). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Activation of the following components on vehicles with a parking heater: Recirculation Pump -V55-, Heater Coolant Shut-Off Valve -N279-.
- The activation of the A/C Compressor Regulator Valve -N280- (compressor switch off controls and A/C compressor actual current) for vehicles without a high voltage system.
- The activation of the Electrical A/C Compressor -V470- (compressor switch off controls and A/C compressor speed) for vehicles with a high voltage system.
- Coolant temperature and the outside air temperature.
- Measured value for the refrigerant pressure sensor (A/C Pressure/Temperature Sensor -G395- / High Pressure Sensor -G65-).
There are different designations, depending on the vehicle. The A/C Pressure/Temperature Sensor -G395- is designated as High Pressure Sensor -G65- on the Audi A6 e-tron. It exchanges the data with the Thermal Management Control Module -J1024- on this vehicle. On all other vehicles (except for the Audi A6 e-tron), the sensor is designated as the A/C Pressure/Temperature Sensor -G395-. For these vehicles, it exchanges data with the Climatronic Control Module -J255- control head. Refer to the Appropriate Wiring Diagram.
Checking
Set the following on the Climatronic Control Module -J255- control head for the "Basic" version:
- "Auto" operating mode - the indicator lamp in the AUTO button -1- illuminates.
- Temperature preset "Cold" - both dials -2 and 5- set at stop "cold".
- A/C compressor turned on - The indicator lamp in the AC -button -6- illuminates.
- Preset for the fresh air blower -4- "maximum speed".
The Rear Temperature Selection Potentiometer -G538- -1- is all the way on "cold", if applicable.
The Rear Temperature Selection Potentiometer -G538- is installed only for vehicles with the "Basic" A/C system version in market specific versions in the rear center console.
Set The Following On The Climatronic Control Module -J255- Control Head For The "Comfort" Version:
- "Auto" mode - the indicator lamps in both AUTO buttons -2 and 4- illuminate.
- Temperature preset "cold" via the dials -1 and 5- - "LO" appears for the driver and front passenger side in the display -3- for the Climatronic Control Module -J255- and in the Multi Media Interface display.
- A/C compressor turned on - The indicator lamp in the AC -button -9- illuminates.
- Preselect for the fresh air blower -8- "maximum speed" - in the Climatronic Control Module -J255- display and the Multi Media Interface display, level "10" or greater.
If Equipped, Set The Rear Temperature Selection Potentiometer -E265- To The Following:
- "Auto" mode - the indicator lamps in both of the AUTO -buttons -3 and 6- illuminate.
- Temperature preselect "cold" via the dials -2 and 7- - "LO" for the left and right side in the display -1-.
- Preselect for the fresh air blower -5- "maximum speed" - in the display level "5" or higher.
The indicator lamps in the AUTO buttons go out when the fresh air blower speed is changed manually.
The maximum possible fresh air blower speed depends on several conditions (vehicle voltage, etc.)
-- The activation and function of the auxiliary heater is OK on vehicles with a TDI engine and on vehicles with a high-voltage system (hybrid vehicles and Audi A6 e-tron with a gasoline engine).
The type of auxiliary heating depends on the vehicle equipment level. For vehicles with a TDI engine without the optional "parking heater" equipment and vehicles with a high-voltage system (hybrid vehicles with a gasoline engine), an Auxiliary Heater Heating Element -Z35- (for the Audi A6 Hybrid) or a High-Voltage Heater (PTC) -Z115- (for the Audi A6 e-tron) is installed. On vehicles with the optional "parking heater" and on which the parking heater is activated like the auxiliary heater, the auxiliary heater heating element -Z35- is currently being discontinued and the parking heater is activated like the auxiliary heater. Refer to Auxiliary Heater Heating Element -Z35-, REMOVING AND INSTALLING .
Certain A/C system functions can be switched on and off via the MMI (Multi Media Interface) 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 (Multi Media Interface) 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.
For vehicles with a high-voltage system (hybrid vehicles) and a gasoline engine, an Auxiliary Heater Heating Element -Z35- (for the Audi A6 Hybrid) or a High-Voltage Heater (PTC) -Z115- (for the Audi A6 e-tron) is also currently installed. Refer to ELECTRICAL AUXILIARY HEATER ACTIVATION, CHECKING .
Functions with the engine running (not hybrid vehicles)/active ready mode (vehicles with a high-voltage system):
For vehicles with a high-voltage system (hybrid vehicles or Audi A6 e-tron) and for vehicles with the Start/Stop System, the engine only runs when 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).
Depending on the version of the Climatronic Control Module -J255- control head (or the Thermal Management Control Module -J1024- on the Audi A6 e-tron), the radiator fan(s) (Radiator Fan -V7- and Radiator Fan 2 -V177-) is/are only switched on from a certain refrigerant circuit pressure (currently from a pressure of approximately 9 bar (130 psi)).. The activation of the coolant fan(s) is displayed in the "read measured value" function Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
-- The fresh air blower runs at maximum speed.
The maximum possible fresh air blower speed depends on several conditions (vehicle voltage, etc.)
-- The 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.
If one of these requirements is not met, read out the event memory, perform the output diagnostic test mode and read out the relevant measured value. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
If the requirements above are fulfilled, check the heating output and the activation of the temperature door: for the "Basic" version. Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Basic" VERSION ; for the "Comfort" version. Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Convenience" VERSION .