Audi Q7: Heating Output and Temperature Door Activation, Testing Requirements
- The coolant circuit is bled according to specifications. Refer to → Rep. Gr.19; Coolant System/Coolant; Coolant, Draining and Filling
- The engine is warm (the coolant temperature is higher than 80 ºC (176 ºF) ).
- Radiator and condenser are clean (if necessary, clean).
- All air ducts, covers and seals are OK and properly installed.
- If a vehicle has electric radiator shutters, their function is OK.
- Air flow through dust and pollen filter not obstructed by dirt. Refer to → Chapter "Dust and Pollen Filter, Removing and Installing".
- The air intake for the front heater and A/C unit (in fresh air and recirculating air mode) is not impaired by contamination or retrofitted 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 → Chapter "Air Guide for Glove Compartment Cooling, Removing and Installing".
- The vehicle is not exposed to sunlight.
- The DTC memory for the Front A/C Display Control Head -E87- (and the Rear A/C Display Control Head -E265- on vehicles with a "High" A/C system) was checked and erased, the basic setting was performed and the coding for the Front A/C Display Control Head -E87- (and the Rear A/C Display Control Head -E265- on vehicles with a "High" A/C system) was checked. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- The adaptation of the Front A/C Display Control Head -E87- (and the Rear A/C Display Control Head -E265- on vehicles with a "High" A/C system) was checked. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- The following is set in the MMI (Multi Media Interface) via the "A/C" function in the "Car"/"Vehicle" menu for the regulation of the A/C system: automatic recirculation "off" and "medium" footwell temperature (arrow pointing upward).
Note
- Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
- The various functions for setting the A/C system in the MMI (Multi Media Interface) ("A/C" function in the "Car" / "Vehicle" menu) differ depending on the A/C system version, the vehicle date of manufacture and the vehicle version (and may not be available for all versions). Refer to Vehicle Operating Instructions.
- On USA market vehicles, certain settings for the A/C system via the MMI are no longer available from a specific date of manufacture. Refer to the Owner's Manual. Also pay attention to the coding and adaptation of the Front A/C Display Control Head -E87-. 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.
- The engine is running and the temperature is set to "warm" ("HI" display) on the Front A/C Display Control Head -E87- (and the Rear A/C Display Control Head -E265- if present) and in the MMI display.
- The Coolant Shut-Off Valve -N82- is not activated.
- For vehicles with a regulated coolant circuit (only installed in certain engines), the activation and function of these components are OK (for example, a regulated coolant pump and Cylinder Head Coolant Valve -N489-). Refer to → Rep. Gr.19; Coolant System/Coolant; Connection Diagram - Coolant Hoses.
Note
For vehicles with an engine with a regulated coolant circuit (for example, with a regulated coolant pump and a Cylinder Head Coolant Valve -N489-), there is currently no Coolant Shut-Off Valve -N82- 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 → Rep. Gr.19; Coolant System/Coolant; Connection Diagram - Coolant Hoses.
- The Heater Coolant Shut-Off Valve -N279- is not activated for vehicles with a parking heater.
- The Coolant Recirculation Pump -V50- is activated.
- Depending on the engine, the Recirculation Pump -V55- is activated on vehicles with a parking heater.
Note
- If this component is activated on vehicles with a Coolant Shut-Off Valve -N82- (not installed on all vehicles) or with a Heater Coolant Shut-Off Valve -N279-, the vehicle interior is not heated. Refer to 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 Front A/C Display Control Head -E87-:
- The measured values of the following temperature sensors (Left Front Upper Body Vent Temperature Sensor -G385-, Right Front Upper Body Vent Temperature Sensor -G386-, Left Footwell Vent Temperature Sensor -G261-, Right Footwell Vent Temperature Sensor -G262- and Evaporator Vent Temperature Sensor -G263-).
- The measured value for the Rear Upper Body Vent Temperature Sensor -G537- (only on a vehicle with a "Low", "Mid" and "Mix" A/C system without and with a rear air distribution housing, without a rear heater and A/C unit).
- The activation of the following components (Fresh Air Blower -V2-, Rear Fresh Air Blower -V80- only on a vehicle with a "Mid", "Mix" or "High" A/C system with air distribution housing or rear heater and A/C unit and with a Rear A/C Display Control Head -E265-)
- The activation of the following components (Radiator Fan -V7-, Radiator Fan 2 -V177-).
- The activation of the following components (if equipped, 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 A/C Compressor Regulator Valve -N280- (compressor shutoff conditions and actual compressor current)
- The coolant temperature and the ambient temperature.
- The measured value for the High Pressure Sensor -G65- (refrigerant pressure).
Note
- Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
- For vehicles with a rear air distribution housing (on a "Mid" or "Mix" A/C system without a rear heater and A/C unit), the air temperature and amount of air that is calculated and regulated by the Front A/C Display Control Head -E87- are also influenced by the setting on the Rear A/C Display Control Head -E265-. However, only the temperature can be adjusted on this Rear A/C Display Control Head -E265-. Refer to → Chapter "Rear A/C Display Control Head -E265-, Removing and Installing, High A/C System".
- For vehicles with a rear heater and A/C unit (on a "High" A/C system), the air temperature and amount of air that is calculated and regulated by the Front A/C Display Control Head -E87- are also influenced by the setting on the Rear A/C Display Control Head -E265-. The temperature for the left and right sides can be adjusted separately on this Rear A/C Display Control Head -E265-. Refer to → Chapter "Rear A/C Display Control Head -E265-, Removing and Installing, High A/C System".
Checking
The following is set on the Front A/C Display Control Head -E87-:
- "Auto" mode (indicator lamp in the AUTO button lights up).
- "Cold" temperature setting for the driver and front passenger side ("LO" for the driver and front passenger side).
- A/C compressor is switched on and maximum cooling output is selected (the indicator lamp in the A/C MAX button lights up).
- Fresh air blower (the Fresh Air Blower -V2- and the Rear Fresh Air Blower -V80-) set to "maximum speed" (the display for the Front A/C Display Control Head -E87- and "4 bar (58.01 psi)" display or higher).
For a "Mid" or "Mix" A/C system, the following is set on the Rear A/C Display Control Head -E265-:
- "Cold" temperature setting ("LO").
Note
- Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
- For vehicles with a "Mid" or "Mix" A/C system, the air temperature and amount of air that is calculated and regulated by the Front A/C Display Control Head -E87- are also influenced by the setting on the Rear A/C Display Control Head -E265-. However, only the temperature can be adjusted on this Rear A/C Display Control Head -E265-. Refer to → Chapter "Rear A/C Display Control Head -E265-, Removing and Installing, High A/C System".
For a "High" A/C system, the following is set on the Rear A/C Display Control Head -E265-:
- "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 Front A/C Display Control Head -E87- and the 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.)
- The activation and function of the auxiliary heater is OK on vehicles with a diesel engine and on vehicles with a high-voltage system (hybrid vehicles with a gasoline or diesel engine).
Note
- The type of auxiliary heating depends on the vehicle equipment level. For vehicles with a diesel engine without "parking heater" optional equipment, an Auxiliary Heater Control Module -J604- with an Auxiliary Heater Heating Element -Z35- is installed. For vehicles with "parking heater" optional equipment, there is no Auxiliary Heater Control Module -J604- with Auxiliary Heater Heating Element -Z35- installed, depending on the vehicle version and the parking heater is activated as an auxiliary heater. Refer to → Chapter "Auxiliary Heater, Testing".
- Certain A/C system functions can be switched on and off via the MMI (Multi Media Interface) in the "A/C system" function under the "Car"/"Vehicle" menu. The A/C system control can also be influenced via the presets in the MMI (Multi Media Interface) under the "A/C system" function in the "Car"/"Vehicle" menu. Therefore, check the preset in the MMI first in the case there is a problem with these components. Refer to Infotainment/MMI Operating Instructions.
Functions with Engine Running:
Note
On vehicles with the Start/Stop System, the engine only runs when an additional heat output is needed to reach the set temperature.
- The radiator fan(s) (Radiator Fan -V7- and Radiator 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 -E87-, the radiator fan(s) (Radiator Fan -V7- and Radiator Fan 2 -V177-) are only switched on at a certain refrigerant circuit pressure (currently at a pressure of approximately 9 bar (130.52 psi) ). The activation of the radiator fan(s) is displayed in the "read measured values" function of the Guided Fault Finding. Refer to Vehicle Diagnostic Testerin the "Guided Fault Finding" function.
- The Fresh Air Blower -V2- runs at maximum speed ("4 bars (58.01 psi)" or higher).
- The Rear Fresh Air Blower -V80- (for vehicles with a "Mid", "Mix" or "High" A/C system) 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 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:
- Heating output and activation of the temperature doors. Refer to → Chapter "Heat Output and Temperature Door Activation, Checking".
Heat Output and Temperature Door Activation, Checking
Test requirements are met. Refer to → Chapter "Heating Output and Temperature Door Activation, Testing Requirements".
- Heating output and activation of the temperature doors. Refer to → Chapter "Heating Output and Temperature Control Door Activation, Checking ".
