Audi Q7: Refrigerant Circuit, Charging with Service Station
Note
The entire refrigerant charge can be added to either the
high or low pressure side. Refer to
→ Chapter "Refrigerant R134a Capacities, Refrigerant Oil and
Approved Refrigerant Oils".
- The work procedure is always to be performed as described in
the operating instructions for the A/C service station.
- Before pouring in refrigerant, correct the quantity of
refrigerant oil. Refer to
→ Chapter "Refrigerant R134a Capacities, Refrigerant Oil and
Approved Refrigerant Oils".
- Make sure the A/C Service Station is standing at the same
level as the vehicle (maximum difference: 50 cm) when charging
the refrigerant circuit. If a difference in height is large
enough, a difference between the amount of refrigerant displayed
on the service station and amount actually filled in the circuit
will result (depending on the version of the A/C Service
Station). The ability of the A/C Service Station to perform an
exact filling can change.
- Turn off the ignition.
- Evacuate the refrigerant circuit using the service station.
Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
Additionally on vehicles with an electric operated valves in
the refrigerant circuit, which cannot be opened without power
(for example the Audi Q7 e-tron):
Note
On vehicles with high-voltage system and additional
functions of the A/C system ("heat pump operation" or "cooling
the high-voltage battery") valves may be installed in the
refrigerant circuit which cannot be opened without power. These
valves are opened and closed for example via a step motor and
after switching off the ignition are no longer activated. To
completely drain, correctly discharge and charge the refrigerant
circuit no areas may be closed, for this reason the valves must
be opened before these procedures. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit; System Overview - Refrigerant
Circuit and using the Vehicle Diagnostic Tester in
the "Guided Fault Finding" function.
- Open the electrically activated valves, which to now open
without power using the Vehicle Diagnostic Tester in the "Guided
Fault Finding" function.
All
- Screw out handwheel at quick-release coupling adapter (to
close it).
- Allow an amount of refrigerant to flow into charging hose.
- Check the charging cylinder.
- Screw in hand wheel at the quick-release coupling adapter
(to open it) and charge with the specified quantity of
refrigerant.
- Turn off the service station.
A/C System, Operating after Charging
Note
- If the mechanically driven Air Conditioning (A/C) compressor
was removed, rotate it approximately 10 times by hand before
using it for the first time (during or after installing, for
example before installing the belt) to prevent damage caused by
liquid impact when first switched on (any oil in compressor
cylinder is forced out on rotation).
- If the electronically driven A/C compressor was removed,
activate it after filling the A/C compressor before the A/C
system on via the "basic setting, compressor cut-in" function
for the Guided Fault Finding. Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding" Function for A/C System and
Battery Regulation. This prevents the A/C compressor from being
damaged, for example, by liquid impact when it is first switched
on (any oil in the A/C compression chamber is forced out).
- The vehicle engine drives the mechanically driven A/C
compressor via a belt or shaft. The electronically driven A/C
compressor is driven via an electric motor attached directly to
the A/C compressor (for example on hybrid vehicles).
Operating an A/C System with a Mechanically Driven A/C
Compressor
- Start engine with compressor switched off (version with A/C
clutch).
- Set compressor to minimum output, for example, "Econ" or A/C
off mode (version with no A/C clutch with regulating valve).
- Wait until idle speed has stabilized.
- Switch on the compressor and operate the system for at least
two minutes at idling speed.
- If necessary, check pressures in the refrigerant circuit
using the A/C service station.
- Turn the engine off.
- Screw out the hand wheel on the quick-release coupling
adapter.
- Disconnect the charging hoses from the refrigerant circuit.
- Install the caps.
Operating an A/C System with an Electrically Driven A/C
Compressor
- Operate the A/C compressor using "basic setting, compressor
cut-in" in Guide Fault Finding. Use the Vehicle Diagnostic
Tester"Guided Fault Finding" A/C System and Battery Regulation.
Additionally on vehicles with an electric operated valves in
the refrigerant circuit, which cannot be opened without power
(for example the Audi Q7 e-tron):
- Via the Vehicle Diagnostic Tester the electrically activated
valves which do not open without power for the operation of the
A/C system enable the activation of these valves via the
respective control module (to open or close) using the Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
Note
On vehicles with high-voltage system and additional
functions of the A/C system ("heat pump operation" or "cooling
the high-voltage battery") valves may be installed in the
refrigerant circuit which cannot be opened without power. These
valves are opened and closed for example via a step motor and
after switching off the ignition are no longer activated. To
completely drain, correctly discharge and charge the refrigerant
circuit no areas may be closed, for this reason the valves must
be opened before these procedures. After finishing work on the
activation of these valves are enabled via the respective
control module. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit; System Overview - Refrigerant
Circuit and using the Vehicle Diagnostic Tester in
the "Guided Fault Finding" function.
All
- After the basic setting and If necessary, check pressures in
refrigerant circuit using A/C service station. Refer to
→ Chapter "A/C Service Station, Connecting for Measuring and
Testing".
- Screw out the hand wheel on the quick-release coupling
adapter.
- Disconnect the charging hoses from the refrigerant circuit.
- Install the caps.
Refrigerant to Service Station Reservoir (Charging Cylinder or
Reservoir Bottle), Transferring
- The work procedure is always to be performed as described in
the operating instructions for the Air Conditioning (A/C)
service station.
- A certain quantity of refrigerant is specified as charge for
each air conditioning system. To ensure that neither too much
nor too little refrigerant is added (either would reduce the
cooling output), the charging cylinder has a scale indicating
the weight.
- The volume of a refrigerant changes as a function of
pressure. The scale must therefore be set according to the
pressure in the charging cylinder.
Note
Do not completely drain the reservoir (charging cylinder or
bottle) as the liquid column boundary layer cannot be traced in
the tube during filling (outside visible range).
WARNING
Do not overfill. A completely filled reservoir
(charging cylinder or bottle) will explode when the
temperature rises.
Service Station, Draining
Note
- If it is necessary to drain the service station (for
example, due to extraction of contaminated refrigerant), all
filters and dryers must always be replaced (do not remove filter
and dryer from the air-tight packaging until immediately before
installation to minimize moisture absorption).
- Refrigerant containers filled with contaminated used
refrigerant are referred to as "Recycling containers".
- Thoroughly evacuate the recycling containers prior to
initial filling with refrigerant (if there is air in a
refrigerant container it is not to be filled with refrigerant).
- Different types of refrigerant may not be mixed together
(refrigerant mixtures cannot be recycled and are to be disposed
of). If there is any doubt about the composition of the contents
of the container, the refrigerant recycling company is to be
informed accordingly.
Caution
- When filling recycling containers (compressed-gas
containers), observe applicable regulations, technical
rules and laws.
- Recycling containers are never to be overfilled.
Overfilled containers do not have a sufficient gas
cushion to accommodate the liquid expansion caused by
the effects of heat. There is a danger of rupture.
- To ensure safety, make exclusive use of recycling
containers fitted with a safety valve.
- Recycling containers must be weighed on calibrated
scales during the filling process. The maximum
permissible capacity is 75% (charge factor 0.75) of the
charge weight indicated on the recycling container (the
possibility of refrigerant oil entering the recycling
container along with the refrigerant cannot be ruled
out).
READ NEXT:
General Information
Vehicles with a High Voltage System (Hybrid Vehicles)
Extremely Dangerous Due to High-Voltage
The high-voltage system is under high-voltage. Death or serious
bodily injury by elec
General Information
Vehicles with a High Voltage System (Hybrid Vehicles)
Extremely Dangerous Due to High-Voltage
The high-voltage system is under high-voltage. Death or serious
bodily injury by elec
Note
The arrows in the following illustrations show the direction
of refrigerant flow during flushing (refrigerant flows in
opposite direction of flow when Air Conditioning (A/C) system is
SEE MORE:
Explanation of warning symbols:
Observe all warnings - there is
a risk for injury!
Always follow the
instructions in the operating
manual.
Electrolyte fluid is highly
corrosive. Always
wear protective gloves and eye protection.
First aid: if electrolyte fluid enters the
eyes, immediatel
Overview - Front Display Control Head, "Low" or "Mid" A/C System
General Information. Refer to
→ Chapter "A/C System Control and Regulation Components in
Vehicle Interior".
Depending on vehicle equipment, there are different versions
of the A/C system for the Audi Q7. Make sure to use t