Audi Q7: Cooling Output Test Notes
Note
- A start-stop system is available for certain engines of this
vehicle as optional equipment. Depending on the setting on the
Front A/C Display Control Head -E87- (and if present at the Rear
A/C Display Control Head -E265-) it can prevent the stop
function. If, for example, the "defrost" mode is selected on the
Front A/C Display Control Head -E87-, the stop function is not
possible or will be interrupted and the engine will start as
soon as this operating mode is selected. The same also applies
if the difference between the selected specified temperature and
the measured actual temperature exceeds a certain value in
heating and cooling mode. Refer to Vehicle Diagnostic Tester in
the "Guided Fault Finding" function.
- On this vehicle the Coolant Recirculation Pump -V50- is
activated not only by an active "Stop function" but also with
the engine running for example at the temperature preset "warm"
on the Front A/C Display Control Head -E87- ("HI" is displayed
in the Front A/C Display Control Head -E87- display). In this
vehicle, the Coolant Recirculation Pump -V50- is also activated
to support the coolant pump of the motor. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
- On a vehicle with a "Low" A/C system (without a Rear A/C
Display Control Head -E265-, and without an air distribution
housing or a rear heater and A/C unit) the temperature of the
air which flows from the front heater and A/C unit to the rear
vent is regulated from the Front A/C Display Control Head -E87-
so that the air out of the vent for the front area has an
average temperature. The target temperature for the air from the
vents in the front area is calculated via the setting for the
left and right side on the Front A/C Display Control Head -E87-
from the Front A/C Display Control Head -E87-. However, if a
setting which no longer regulates the temperature (for example,
"HI" for maximum heating or "LO" for maximum cooling) is present
on the Front A/C Display Control Head -E87-, the temperature of
the air from the vents in the front area is no longer regulated.
If, for example, maximum heating "HI" is set on the Front A/C
Display Control Head -E87- for one side and maximum cooling "LO"
for the other side, the air for the vents in the front area is
maximally heated.
- For vehicles with a "Mid" or "Mix" A/C system (with a rear
air distribution housing but 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- version -A-. 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- version -B-.
Refer to
→ Chapter "Rear A/C Display Control Head -E265-, Removing and
Installing, High A/C System".
- 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.
A/C Cooling Output, Testing Requirements
- The ambient temperature is greater than 15 ºC (59 ºF).
- Radiator and condenser are clean (if necessary, clean).
- If a vehicle has electric radiator shutters, their function
is OK.
- The ribbed belt, which drives the A/C compressor, is OK and
is tensioned correctly. The belt pulley is actually driving the
A/C compressor. Refer to
→ Chapter "Overview - Belt Pulley".
- All air ducts, covers and seals are OK and properly
installed.
- Air flow through dust and pollen filter not obstructed by
dirt. Refer to
→ Chapter "Dust and Pollen Filter, Removing and Installing".
- The air intake apparatus (in fresh air and recirculating air
mode) is not impaired by soiling or components installed as
retrofit.
- 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 engine is warm (the coolant temperature is higher than
80 ºC (176 ºF) ).
- 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 a vehicle 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.
- All instrument panel vents and the vents in the rear center
console and in the B-pillar are open.
- The vent for glove compartment cooling (in the glove
compartment) is closed.
- Ensure that the air outlet from the rear footwell vents
(under the front seat) is not blocked by floor mats or other
objects.
- The hood is closed.
- The engine is running.
On the Front A/C Display Control Head -E87- the following is
adjusted:
- "Auto" mode (the indicator lamps in both
AUTO buttons illuminate).
- Temperature preselection "cold" for the driver and front
passenger side (display "LO" for the driver and front passenger
side in the Front A/C Display Control Head -E87- display and in
the Multi Media Interface display).
- The A/C compressor is on (the indicator lamp in the
A/C MAX button of the Front A/C
Display Control Head -E87- comes on).
- Preset for the Fresh Air Blower -V2-"maximum speed" (shown
in the display of the Front A/C Display Control Head -E87-).
For vehicles with a "Mid" or "Mix" A/C system, the following
is set on the Rear A/C Display Control Head -E265-:
- Temperature preset "cool" (display "LO" ).
For vehicles with a "High" A/C system, the following is set
on the Rear A/C Display Control Head -E265-:
- "Auto" mode (the indicator lamps in 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 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.)
Functions with Engine Running
- 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 request to switch the radiator fan (the Radiator
Fan -V7- under Radiator Fan 2 -V177-) is sent first from a
specific refrigerant circuit pressure to the respective Engine
Control Module -J623- (currently at a pressure of approximately
9 bar (130.52 psi) ). The radiator fan is then switched on by the
Engine Control Module -J623-. The activation of the radiator fan
is displayed in the "read measured value" function in the Guided
Fault Finding. Refer to Vehicle Diagnostic Tester.
- The Fresh Air Blower -V2- runs at maximum speed.
- The Rear Fresh Air Blower -V80- (for vehicles with a "Mid",
"Mix" or "High" A/C system) runs at maximum speed.
Note
- On vehicles with a "Low" A/C system no Rear Fresh Air Blower
-V80- is installed.
- The maximum possible fresh air blower speed depends on
several conditions (coolant temperature, vehicle voltage, etc.)
- The front A/C system goes in recirculating air mode
(approximately one minute after starting the engine, the back
pressure/fresh air door is closed and the air recirculation door
is opened. The Fresh Air Blower -V2- extracts the air from
passenger compartment below instrument panel / behind the glove
compartment).
Note
When one of these requirements is not fulfilled, call up the
DTC memory 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) perform the output diagnostic test mode and read out
the measured values. Refer to Vehicle Diagnostic Tester in the
"Guided Fault Finding" function.
READ NEXT:
Special tools and workshop equipment
required
Vehicle Diagnostic Tester with the "Guided Fault Finding"
function and the corresponding connection lines. Refer to
Workshop Equipment.
A standard t
- In the "read measured values" function, select the display
group with the measured values for the A/C compressor activation
and the refrigerant circuit pressure. Refer to Vehicle
Diagnostic
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
co
SEE MORE:
Fresh Air Door Motor -V438-, Removing and Installing
Note
Therefore, perform the basic setting for the A/C system
after installation of the adjustment motor. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
Using the "output diagnostic test mode" and "basic set
Winter tires significantly improve the vehicle's
handling when driving in winter conditions. Because
of their construction (width, compound,
tread pattern), summer tires provide less traction
on ice and snow.
Use winter tires on all four wheels.
Only use winter tires that are approved for your
v