Audi Q7: Heating Output and Temperature Control Door Activation, Checking
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 "Low" A/C system, there is no air
distribution housing and no rear heater and A/C unit installed.
- For vehicles with a "Mid" or "Mix" A/C system, a rear air
distribution housing is installed (but no rear heater and A/C
unit).
- For vehicles with a "High" A/C system, a rear heater and A/C
unit is installed.
- Close the engine hood.
- Close the doors, the engine hood, the windows, the sliding
sunroof and the rear lid.
- Open all instrument panel vents and the vents in the rear
center console.
- Open the vents in the left and right B-pillars.
- Close the vent for glove compartment cooling (in the glove
compartment).
- Turn on the ignition and activate the ready mode. The engine
starts automatically as needed (on vehicles with a Start/Stop
System).
- Start the engine.
Set the following on the Front A/C Display Control Head
-E87-:
Note
By selecting the "SYNC" function on the Front A/C Display
Control Head -E87- (only on version -B-),
the settings on the front driver side are applied to the front
passenger side and also to the Rear A/C Display Control Head
-E265-.
- Select the SYNC function on the
Front A/C Display Control Head -E87-.
- Select "Auto" mode for the driver side (and the front
passenger side) (the indicator lamp in the
AUTO button(s) illuminate).
- Temperature on the driver and front passenger side set to
"cold" ("LO" in the Front A/C Display Control Head -E87- and MMI
display).
- The A/C compressor is on (the indicator lamp in the
A/C MAX button comes on).
- Fresh air blower (front and rear) set to "maximum speed"
(shown in the Front A/C Display Control Head -E87- and MMI
display).
- Set the airflow direction on the driver and front passenger
side to "footwell" and "instrument panel vent" using the knob or
buttons on the Front A/C Display Control Head -E87- (shown in
the display or the buttons for the Front A/C Display Control
Head -E87-).
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".
- Set the air flow direction via the dials on the Rear A/C
Display Control Head -E265- for the left and right side to
"footwell" and "B-pillar vents" (shown in the display of the
Rear A/C Display Control Head -E265-).
Note
- The indicator lamps in the AUTO
-buttons turn off when performing manual changes for the airflow
direction and/or the fresh air blower speed.
- The maximum possible fresh air blower speed depends on
several conditions (coolant temperature, vehicle voltage, etc.)
- The instrument panel vents, the B-pillar vents, and the
vents in the rear center console are open.
- Initiate Guided Fault Finding for the front A/C system and
select the "Read measured values" function. Refer to Vehicle
Diagnostic Tester.
- Let the A/C system run a few minutes at maximum cooling
output (A/C compressor is switched on, indicator lamp in the
A/C MAX button comes on).
- Compare the measured value for the Evaporator Vent
Temperature Sensor -G263- with the measured values from the Left
Front Upper Body Vent Temperature Sensor -G385-, the Right Front
Upper Body Vent Temperature Sensor -G386-, the Left Footwell
Vent Temperature Sensor -G261-, the Right Footwell Vent
Temperature Sensor -G262- (and the Rear Upper Body Vent
Temperature Sensor -G537-, which is only on a "Low", "Mid" or
"Mix" A/C system).
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 Rear Upper Body Vent Temperature Sensor -G537- is only
installed on vehicles without a rear heater and A/C unit (with a
"Low", "Mid" or "Mix" A/C system, with or without a Rear A/C
Display Control Head -E265- version -A-).
Specified Values
- After five minutes, the temperature sensor measured values
(downstream of the heater core) for the 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 the
Rear Upper Body Vent Temperature Sensor -G537-) may be greater
than the value for the Evaporator Vent Temperature Sensor -G263-
by a maximum of 10 ºC (50 ºF).
Note
Due to the design of the heater and A/C unit and the air
routing in the vehicle, there is always a certain increase in
air temperature.
If the required values are not reached, perform a fault finding at a
temperature increase on the evaporator.
Note
- If the measured value in one or two temperature sensors
deviates from the measured values of the other temperature
sensors, check this temperature sensor and the control motor
which activates the temperature control door upstream from this
temperature sensor. Refer to Vehicle Diagnostic Tester in the
"Guided Fault Finding" function.
- 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.
Then additionally in vehicles with a "High" A/C system (with
a rear heater and A/C unit and a Rear A/C Display Control Head
-E265- version -B-).
- Initiate Guided Fault Finding of the rear A/C system and
select the "read measured values" function. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
- Compare the measured value of the Evaporator Vent
Temperature Sensor -G263- with the measured value of the Left
Rear Upper Body Vent Temperature Sensor -G635-, the Right Rear
Upper Body Vent Temperature Sensor -G636-, the Left Rear
Footwell Vent Temperature Sensor -G637- and the Right Rear
Footwell Vent Temperature Sensor -G638-.
Specified Values
- The displayed measured values may be a maximum of 10 ºC (50
ºF) greater than the displayed measured value of the Evaporator
Vent Temperature Sensor -G263-.
If the required values are not reached. Refer to
→ Chapter "Malfunction Determination if Cooling Output of Front
A/C System is OK but Required Values not Achieved in Rear".
Continuation for All Vehicles
- Set the temperature on the driver and front passenger side
to "warm" using the knobs on the Front A/C Display Control Head
-E87- ("Hi" in the displays for the Head Front A/C Display
Control -E87-).
- For a vehicle with a "Mid" or "Mix" A/C system, set the
temperature to "warm" using the buttons on the Rear A/C Display
Control Head -E265- ("Hi" in the display for the Rear A/C
Display Control Head -E265-).
- For a vehicle with a "High" A/C system, set the temperature
on the driver and front passenger side to "warm" using the
buttons on the Rear A/C Display Control Head -E265- ("Hi" in the
displays for the Rear A/C Display Control Head -E265-).
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 Front A/C Display Control Head -E87-
version -B-, the settings on the
front driver side are applied to the front passenger side and
also to the Rear A/C Display Control Head -E265- by selecting
the "SYNC" function.
The display for the preselected temperature changes for all
vents (the driver and front passenger side, for the left and
right rear) from "LO" to "HI".
- Check the measured values for the 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 Rear
Upper Body Vent Temperature Sensor -G537-, only on a "Low",
"Mid" or "Mix" A/C system) that are displayed in the "Read
measured values" function of Guided Fault Finding for the Front
A/C Display Control Head -E87-. Refer to Vehicle Diagnostic
Tester in the "Guided Fault Finding" function.
Note
The Rear Upper Body Vent Temperature Sensor -G537- is only
installed on vehicles with a "Low", "Mid" or "Mix" A/C system
(with or without a rear air distribution housing, as well as
with or without a Rear A/C Display Control Head -E265- version
-A-.
Specified Values
- The measured temperature for all temperature sensors
increases to above 50 ℃ (122 ºF) (depending on the engine
temperature at the time).
Note
- For vehicles with a Start/Stop System, the Coolant
Recirculation Pump -V50- maintains the coolant flow through the
heater core for the heater in the heater and A/C unit when the
engine is not running.
- The Coolant Recirculation Pump -V50- can be installed in
different locations. In most vehicles, it is installed in the
engine compartment (on a 6-cylinder TDI engine, for example, it
is under the right fender).
- The activation of the Coolant Recirculation Pump -V50-
varies. In most vehicles, it is activated by the respective
Engine Control Module -J623- at the request of the Front A/C
Display Control Head -E87-. Refer to Vehicle Diagnostic Tester
in the "Guided Fault Finding" function and refer to
→ Wiring diagrams, Troubleshooting & Component locations.
The required values are achieved at all temperature sensors:
- Continuation of testing for vehicles with a "Low", "Mid" or "Mix" A/C
system (without a rear heater and A/C unit, with or without a Rear A/C
Display Control Head -E265- version -A-).
- Continuation of testing for vehicles with a "High" A/C system (with a
rear heater and A/C unit and a Rear A/C Display Control Head -E265- version
-B-).
Note
- For vehicles with a "Low" A/C system, there is no Rear A/C
Display Control Head -E265-, no air distribution housing and no
rear heater and A/C unit installed.
- For vehicles with a "Mid" or "Mix" A/C system, a Rear A/C
Display Control Head -E265- version -A-
and a rear air distribution housing is installed (but no rear
heater and A/C unit). Refer to
→ Chapter "Rear A/C Display Control Head -E265-, Removing and
Installing, High A/C System".
- For vehicles with a "High" A/C system, a Rear A/C Display
Control Head -E265- version -B- and
a rear heater and A/C unit are installed. Refer to
→ Chapter "Rear A/C Display Control Head -E265-, Removing and
Installing, High A/C System".
- If the required values are not reached on any of the
temperature sensors:
- Check the activation and function of the Coolant Pump -V50-
(of the Recirculation Pump -V55-) and of the Coolant Shut-Off
Valve -N82- (of the Heater Coolant Shut-Off Valve -N279-). Refer
to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
- Check the incorporation of the A/C system into the coolant
circuit. Refer to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit".
- Check the coolant circuit bleeding. Refer to
→ Rep. Gr.19; Coolant System/Coolant; Coolant, Draining and
Filling
- Check the heating output of the A/C system at an engine
speed of approximately 1500 to 2000 RPM (repeat the test at a
higher engine speed). If the required heating output is reached
at this engine speed, the malfunction is not in the heater and
A/C unit, but rather in the coolant circuit (incorporation of
the A/C system into the coolant circuit, engine coolant pump
delivery rate, the coolant flowing through heater core in the
front heater and A/C unit, incorporation of the Coolant
Recirculation Pump -V50- into the coolant circuit, etc.). Refer
to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit" and
→ Rep. Gr.19; Coolant System/Coolant; Connection Diagram -
Coolant Hoses.
- Check that the engine coolant pump is functioning correctly
(if a coolant pump is faulty or a Coolant Recirculation Pump
-V50- is incorporated incorrectly, there may not be enough
coolant flowing through the heater core for the heater in the
front and rear heater and A/C unit). Refer to
→ Rep. Gr.19; Coolant Pump/Coolant Thermostat; Overview -
Electric Coolant Pump.
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 circulation.
If the required values are not reached at only one or two
temperature sensors:
- Check the activation and function of the various actuators
for the temperature control doors in the front heater and A/C
unit. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
- Check the measured values of the various temperature
sensors. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
- Perform fault finding in the case of an increase in temperature after
the evaporator.
- Check the foam seal on the heat core for the heater for the front
heater and A/C unit.
- On vehicles with an Auxiliary Heater Control Module -J604-
(and an Auxiliary Heater Heating Element -Z35-) check the
separation between the left and the right side in the front
heater and A/C unit via the installation slot for the Auxiliary
Heater Heating Element -Z35-. Refer to
→ Chapter "Auxiliary Heater Control Module -J604- (with
Auxiliary Heater Heating Element -Z35-) Checking, Removing and
Installing".
- Check the coolant circuit bleeding. Refer to
→ Rep. Gr.19; Coolant System/Coolant; Coolant, Draining and
Filling
Additional check for vehicles with a
"High" A/C system (with a rear heater and A/C unit) check the
heating output of the rear heater and A/C unit.
Note
- Continuation of the heat output test and the activation of
the temperature control doors on a vehicle with a rear heater
and A/C unit (with a "High" A/C system).
- 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 heating output and activation of the temperature doors
of the front A/C system were tested and are OK. Refer to
→ Chapter "Heat Output and Temperature Door Activation, Checking"
- Read the "measured values" of the Rear A/C Display Control
Head -E265- the displayed measured values for the various
temperature sensors: left vent temperature sensor -G635-,
-G636-, -G637- and -G638-. Refer to Vehicle Diagnostic Tester in
the function "Guided Fault Finding".
Note
A commercially available thermometer can also be used to
measure the temperature of the air coming out of the vents in
the rear center console (left and right).
Specified Values
- The measured temperature for all temperature sensors
increases to above 50 ℃ (122 ºF) (depending on the engine
temperature at the time).
The required values are achieved at all temperature sensors:
- Continuation of the test.
If the required values are not reached on any of the
temperature sensors:
- Check the activation and function of the Coolant Pump -V50-
(of the Recirculation Pump -V55-) and of the Coolant Shut-Off
Valve -N82- (of the Heater Coolant Shut-Off Valve -N279-). Refer
to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
- Check the incorporation of the rear A/C system into the
coolant circuit. Refer to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit".
- Check the coolant circuit bleeding. Refer to
→ Rep. Gr.19; Coolant System/Coolant; Coolant, Draining and
Filling
- Check the heating output at an engine speed of approximately
1500 to 2000 RPM (repeat the test at a higher engine speed). If
the required heating output is not reached at this engine speed,
the malfunction is not in the heater and A/C unit but rather in
the coolant circuit (check the incorporation of the A/C system
in the coolant circuit, engine coolant pump delivery, the
coolant flowing through the heater core in the rear heater and
A/C unit, etc.). Refer to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit" and
→ Rep. Gr.19; Coolant System/Coolant; Connection Diagram -
Coolant Hoses.
- Check the regulator for the coolant temperature in the
engine (the engine coolant may not heat properly if the
regulator is malfunctioning). Refer to
→ Rep. Gr.19; Coolant Pump/Coolant Regulation; Coolant
Regulator, Checking .
- Check that the engine coolant pump is functioning correctly
(if a coolant pump is faulty or a Coolant Recirculation Pump
-V50- is incorporated incorrectly, there may not be enough
coolant flowing through the heater core for the heater in the
front and rear heater and A/C unit). Refer to
→ Rep. Gr.19; Coolant Pump/Coolant Regulation; Overview -
Coolant Pump.
- Check the foam seal on the heat core for the heater for the
rear heater and A/C unit. Refer to
→ Chapter "Heater Core, Removing and Installing".
If the required values are not reached at only one or two
temperature sensors:
- Check the activation and function of the various actuators
for the temperature control doors in the rear heater and A/C
unit. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
- Check the measured values of the various temperature sensors
in the rear air ducts. Refer to Vehicle Diagnostic Tester in the
"Guided Fault Finding" function.
Continuation of the heating output test
of the front heater and A/C units (check the separation for the
temperature control between the left and right side in the
heater and A/C unit).
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.
- Using the knob on the Front A/C Display Control Head -E87-
adjust the temperature setting for the front passenger side to
"cold" ("LO" is displayed) in the display of the Front A/C
Display Control Head -E87- for the front passenger side.
- On vehicles with a "High" A/C system using the knob on the
Rear A/C Display Control Head -E265- (version
-B-) adjust the temperature setting
for the passenger side rear to "cold" ("LO" is displayed) in the
display of the Rear A/C Display Control Head -E265- for the rear
passenger side.
- The temperature setting for the driver side (front and rear)
remains on "warm" ("HI" is displayed) in the display of the
Front A/C Display Control Head -E87- (on a "Mix" or "High" A/C
system and the Rear A/C Display Control Head -E265- on a "Mid",
"Mix" or "High" A/C system).
Note
- On a vehicle with a "Mid" or "Mix" A/C system the
temperature setting for the (front) driver side remains on
"warm" ("HI" is displayed) in the display of the Front A/C
Display Control Head -E87-. The adjustment on the Rear A/C
Display Control Head -E265- for the rear remains on "warm" ("HI"
is displayed in the display).
- On a vehicle with a "High" A/C system the temperature
setting for the driver side (front and rear) remains on "warm"
("HI" is displayed) in the display of the Front A/C Display
Control Head -E87- and the Rear A/C Display Control Head -E265-.
- Initiate Guided Fault Finding of the front A/C system and
select the "read measured values" function. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
- Let the A/C system run for a few minutes with this setting
(the A/C compressor is switched on, the indicator lamp in the
A/C MAX button illuminates).
- Compare the measured value for the Evaporator Vent
Temperature Sensor -G263- with the measured values from the Left
Front Upper Body Vent Temperature Sensor -G385-, the Right Front
Upper Body Vent Temperature Sensor -G386-, the Left Footwell
Vent Temperature Sensor -G261-, the Right Footwell Vent
Temperature Sensor -G262- (and the Rear Upper Body Vent
Temperature Sensor -G537-, which is only on a "Low", "Mid" or
"Mix" A/C system).
Note
- The Rear Upper Body Vent Temperature Sensor -G537- is only
installed on vehicles with a "Low", "Mid" or "Mix" A/C system
with or without a rear air distribution housing, (with or
without a Rear A/C Display Control Head -E265- version
-A-).
- At the temperature setting "warm" for one side (the driver
or front passenger side), the target outflow temperature at the
evaporator in the front heater and A/C unit is regulated by the
Climatronic Control Module -J255- to a higher value (up to
approximately 10 ºC (50 ºF) ).
- On a vehicle with a "Low" A/C system (without a Rear A/C
Display Control Head -E265-, without an air distribution housing
and 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.
- On a vehicle with a "Mid" or "Mix" A/C system (with a
version -A-Rear A/C Display Control
Head -E265-, and an air distribution housing but without 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 air distribution
housing 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 adjustment for the
left and right side on the Front A/C Display Control Head -E87-
and the adjustment Rear A/C Display Control Head -E265- 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 depending on the adjustment on the Rear A/C Display
Control Head -E265- the air for the vents in the front area is
maximally heated or cooled.
Specified values on a vehicle with a "Low"Mid" or "Mix" A/C
system:
- A temperature which corresponds approximately to the
temperature on the warmer side is set on the Rear Upper Body
Vent Temperature Sensor -G537- (ignore the measured value).
Specified values on a vehicle with a "High" A/C system:
- On the Left Front Upper Body Vent Temperature Sensor -G385-
and Left Footwell Vent Temperature Sensor -G261-, the
temperature remains above 50 ºC (122 ºF) (depending on the
current engine temperature).
- On the Right Front Upper Body Vent Temperature Sensor -G386-
and Right Footwell Vent Temperature Sensor -G262-, the
temperature drops to a value which may be a maximum of 15 ºC (59
ºF) higher than the measured value of the Evaporator Vent
Temperature Sensor -G263- within 5 minutes.
- The temperatures of the temperature sensors on one side
(Left Front Upper Body Vent Temperature Sensor -G385- and Left
Footwell Vent Temperature Sensor -G261-) and ( Right Front Upper
Body Vent Temperature Sensor -G386- and Right Footwell Vent
Temperature Sensor -G262-) displayed in the "read measured
values" function of the Guided Fault Finding equalize within 5
minutes (the particular temperature difference is less than 9 ºC
(48.2 ºF) ).
Note
- For vehicles with a Start/Stop System, the Coolant
Recirculation Pump -V50- maintains the coolant flow through the
heater core for the heater in the heater and A/C unit when the
engine is not running.
- The Coolant Recirculation Pump -V50- can be installed in
different locations. In most vehicles, it is installed in the
engine compartment (on a 6-cylinder TDI engine, for example, it
is under the right fender). Refer to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit".
- The activation of the Coolant Recirculation Pump -V50-
varies. In most vehicles, it is activated by the respective
Engine Control Module -J623- at the request of the Front A/C
Display Control Head -E87-. Refer to Vehicle Diagnostic Tester
in the "Guided Fault Finding" function and refer to
→ Wiring diagrams, Troubleshooting & Component locations.
- On a vehicle with a "Low"Mid" or "Mix" A/C system (without
a rear heater and A/C unit) with and without a rear air
distribution housing and Rear A/C Display Control Head -E265-
(version -A-) adjust the
temperature setting for the front passenger side to 18 ºC (64.4
ºF) and for the driver side to 28 ºC (82.4 ºF).
- A temperature between the values for the left and right is
set on the Rear Upper Body Vent Temperature Sensor -G537- (the
air for the left and right side from the front heater and A/C
unit mixes in the rear air distribution housing).
- On vehicles with a "High" A/C system initiate the Guided
Fault Finding of the rear A/C system (with a rear heater and A/C
unit and a Rear A/C Display Control Head -E265- (version
-B-) select the function "Read
measured values". Refer to Vehicle Diagnostic Tester.
- Compare the measured value of the Evaporator Vent
Temperature Sensor -G263- to the measured values of the Left
Rear Upper Body Vent Temperature Sensor -G635-, the Right Rear
Upper Body Vent Temperature Sensor -G636-, the Left Rear
Footwell Vent Temperature Sensor -G637- and the Right Rear
Footwell Vent Temperature Sensor -G638-.
Specified values on a vehicle with a "High" A/C system:
- The temperature on the Left Rear Upper Body Vent Temperature
Sensor -G635- and Left Rear Footwell Vent Temperature Sensor
-G637- remains higher than 50 ºC (122 ºF) (depending on the
current engine temperature).
- On the Right Rear Upper Body Vent Temperature Sensor -G636-
and Right Rear Footwell Vent Temperature Sensor -G638-, the
temperature drops to a value which is a maximum of 15 ºC (59 ºF)
higher than the measured value of the Evaporator Vent
Temperature Sensor -G263- within five minutes.
- The temperatures of the temperature sensors on one side
(-G635- and -G637-) and (-G636-, -G638- and -G262-) ) displayed
in the "read measured values" function of the Guided Fault
Finding equalize within five minutes (the particular temperature
difference is less than 9 ºC (48.2 ºF) ).
If the target values are reached, the test is complete.
Note
If the temperature for the driver side is set to "LO" and
the temperature for the front passenger side is set to "HI",
this test can be performed again using opposite measured values.
If the specified values are not reached, check the
following:
- Check the activation and functionality of the various
adjustment motors for the temperature doors in the front or rear
heater and A/C unit (depending on where the target values were
not reached). Refer to Vehicle Diagnostic Tester in the "Guided
Fault Finding" function.
- Check the foam seal on the heat core for the heater of the
front or rear heater and A/C unit (depending on where the target
values were not reached). Refer to
→ Chapter "Heater Core, Removing and Installing" and
→ Chapter "Heater Core, Removing and Installing".
- Check the coolant circuit bleeding. Refer to
→ Rep. Gr.19; Coolant System/Coolant; Coolant, Draining and
Filling.
- In vehicles with an Auxiliary Heater Heating Element -Z35-,
check the separation between the left and right side in the
front heater and A/C unit via the installation shaft for the
Auxiliary Heater Heating Element -Z35- (only if the values are
not reached in the front heater and A/C unit). Refer to
→ Chapter "Auxiliary Heater Control Module -J604- (with
Auxiliary Heater Heating Element -Z35-) Checking, Removing and
Installing".
- Check the activation and function of the Coolant Pump -V50-
(of the Recirculation Pump -V55-) and of the Coolant Shut-Off
Valve -N82- (of the Heater Coolant Shut-Off Valve -N279-). Refer
to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
- Check that the engine coolant pump is functioning correctly
(if a coolant pump is faulty or a Coolant Recirculation Pump
-V50- is incorporated incorrectly, there may not be enough
coolant flowing through the heater core for the heater in the
front and rear heater and A/C unit). Refer to
→ Rep. Gr.19; Coolant System/Coolant; Connection Diagram -
Coolant Hoses.
- Check the incorporation of the A/C system into the coolant
circuit. Refer to
→ Chapter "Incorporating the Heating and A/C System in the
Coolant Circuit".
Fault finding in the case of a
temperature increase downstream from the evaporator (in the
front heater and A/C unit)
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.
- Clamp off both coolant hoses to the front heater and A/C unit heater core,
for example using Hose Clamps - Up To 40mm -3093-.
- Repeat the test for heating output and temperature door activation.
- Compare the measured value of the Evaporator Vent Temperature Sensor -G263-
with the measured value of the Left Rear Upper Body Vent Temperature Sensor
-G635-, the Right Rear Upper Body Vent Temperature Sensor -G636-, the Left Rear
Footwell Vent Temperature Sensor -G637- and the Right Rear Footwell Vent
Temperature Sensor -G638- (as well as the Rear Upper Body Vent Temperature
Sensor -G537- on a "Low""Mid" or "Mix" A/C system).
- Do the measured values of the temperature sensors match when the coolant
hoses are clamped off, and are the required values reached?
- Remove Hose Clamps - Up To 40mm -3093- from both coolant hoses.
- Check the activation and function of the Left Temperature Control Door
Motor -V158-, the Right Temperature Control Door Motor -V159-, and the Rear
Temperature Control Door Motor -V137- and the activation of each temperature
door.
- Check the sensor with the deviating measured value for correct installation
and check its electrical connections for contact resistance. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" Function and
→ Wiring diagrams, Troubleshooting & Component locations.
- Correct the cause for the incorrect measured value, and if necessary,
replace the defective sensor.
- Are the temperature flap activation and functionality OK?
- Check the function of the temperature door that increases the temperature.
- Repeat the heat output test and temperature door activation.
- Correct the cause of the malfunction. Refer to Vehicle Diagnostic Tester in
the "Guided Fault Finding" function and
→ Wiring diagrams, Troubleshooting & Component locations.
- Repeat the heat output test and temperature door activation.
READ NEXT:
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
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
SEE MORE:
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.
1 - Instrum
General Information - Multifunction Steering Wheel
Buttons are integrated in the steering wheel for easier
operation of Infotainment, telephone and the navigation system.
On vehicles with Tiptronic, rocker switches are also installed
on the left and right.
The Multifunction Steering Wheel Control