Heating Output And Temperature Door Activation, Testing Requirements

On Vehicles with A High Voltage System (hybrid vehicles) 

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system, refer to appropriate 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 appropriate HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS.) and "always follow the warnings when working on the high voltage system" .

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

-- Charge the vehicle battery, for example, using the Battery Charger VAS 5904 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, PREPARING FOR SUPPORT MODE .

-- 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.

All Vehicles 

• The coolant circuit is bled according to specifications, refer to FOR ENGINE(S) CTUA & CGXB - COOLANT, DRAINING AND FILLING , FOR ENGINE(S) CPNB - COOLANT, DRAINING AND FILLING or FOR ENGINE(S) CEUC & CRDB - COOLANT, DRAINING AND FILLING
• 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).

• 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.

On Vehicles with A High Voltage System (hybrid vehicles) 

• 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.
• When the ignition is turned on and the temperature preset is "warm" on the Climatronic Control Module -J255- A/C control head ("HI" is displayed in the A/C control head and the Multi Media Interface display).

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" in the display for the A/C system control head and the Multi Media Interface).

For Vehicles without A High Voltage System 

• Engine is running.
• When the engine is running and the temperature selection is set at "warm" on the Climatronic Control Module -J255- (for example, "HI" is displayed on the "Comfort" version of the A/C system for the driver and passenger side in the Climatronic Control Module -J255- and on the Rear A/C Display Control Head -E265- in the display).

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" in the display for the A/C system control head and the Multi Media Interface).

-- 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.

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-.
• 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 A/C Pressure/Temperature Sensor -G395- (refrigerant pressure).

Checking 

Fig 1: 'Basic' Version Of Climatronic Control Module -J255- Control Head

Courtesy of AUDI OF AMERICA, LLC

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.

Fig 2: Rear Temperature Selection Potentiometer

Courtesy of AUDI OF AMERICA, LLC

Set the following on the Climatronic Control Module -J255- control head for the "Comfort" version:

Fig 3: "Comfort" Version Of Climatronic Control Module -J255- Control Head

Courtesy of AUDI OF AMERICA, LLC

• "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:

Fig 4: Rear Temperature Selection Potentiometer -E265-

Courtesy of AUDI OF AMERICA, LLC

• "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.

-- On vehicles with a TDI engine and on vehicles with a high voltage system (hybrid vehicles with gasoline engines), check if the activation and functionality of the auxiliary heater is OK.

Functions when the Engine Is Running (non-hybrid vehicles) / Activated Ready Mode (hybrid vehicles) 

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

-- The fresh air blower runs at maximum speed.

-- 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 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, "Basis" VERSION ; for the "Comfort" version, refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Convenience" VERSION .