Audi Q5: Refrigerant Cut-Off Valve
Note
- There are different versions of the shut-off valve with
different functions and with different names. The following
illustrated Hybrid Battery Refrigerant Shut-Off Valve 1 -N516-
is for example installed on an Audi Q7 hybrid. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit; System Overview - Refrigerant
Circuit.
- There are various designations, depending on the function
and the vehicle. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit; System Overview - Refrigerant
Circuit.
Shut-Off Valve with Two Switching States (Open Or Closed)
- Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- (for
example the Audi Q5 Hybrid)
- Heater and A/C Unit Refrigerant Shut-Off Valve -N541- (for
example on Audi A3 e-tron)
- High-Voltage Battery Heater Core Refrigerant Shut-Off Valve
-N542- (for example on Audi A3 e-tron)
- Refrigerant Shut-Off Valve -V424- (for example on Audi Q7
e-tron)
- If the shut-off -A- is not
activated by the electronics, it is open and lets the
refrigerant flow through to the evaporator in the A/C unit.
- The shut-off valve -A- is
installed on vehicles with the battery cooling module. It is
activated in hybrid mode when no A/C system operation is desired
for the passenger compartment or for the Hybrid Battery Unit
-AX1-, but is necessary for battery cooling.
- Observe the arrow -B- attached
to the shut-off valve -A-, which
shows the flow direction of the refrigerant (from the condenser
to the evaporator in the A/C unit)
- The solenoid coil -C- attached
to the shut-off valve is activated for example from the Battery
Regulation Control Module -J840-
→ Wiring diagrams, Troubleshooting & Component locations.
Use the Vehicle Diagnostic Tester in the "Guided Fault Finding"
Function for the A/C System and the Battery Regulation.
- On a vehicle with two evaporators (one in the A/C unit and
one for example on the Audi Q5 Hybrid) in the battery cooling
module, if the measured temperature on one of the evaporators
corresponds to the target value or the target value falls short,
but does not reach the required target value on the other
evaporator, the following adjustment is performed: the relevant
control module (for example the Battery Regulation Control
Module -J840- n the Audi Q5 hybrid) activates the electric A/C
compressor with increased speed (thereby increasing the A/C
cooling output and decreasing the pressure on the low pressure
side as well as the evaporator temperature) via the A/C
Compressor Control Module -J842-. If the target value falls
short for the temperature of one of the evaporators, the
relevant control module (for example the Battery Regulation
Control Module -J840- on the Audi Q5 Hybrid the Hybrid Battery
Refrigerant Shut-Off Valve 1 -N516- or the Hybrid Battery
Refrigerant Shut-Off Valve 2 -N517-) activates so that the
evaporator which is too cold is no longer supplied with
refrigerant. Use the Vehicle Diagnostic Tester in the "Guided
Fault Finding" Function for the A/C System and
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (for the specific
vehicle).
Shut-Off Valve, which is Regulated via the Characteristic
Curve
- Refrigerant Shut-Off Valve 2 -N640- through Refrigerant
Shut-Off Valve 5 -N643- (for example on Audi Q7 e-tron)
- Refrigerant Expansion Valve 1 -N636- (for example on Audi Q7
e-tron)
- The shut-off valve -A- is activated via a
step motor -B- from the respective control
module via the characteristic curve (opened or closed).
- If the shut-off valve works as a regulator valve (for example on the
Audi Q7 as Refrigerant Expansion Valve 1 -N636-) it is only open until the
temperature for the heat exchanger is reached. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; Refrigerant
Circuit; System Overview - Refrigerant Circuit.
- Shut-off valves activated via the step motor do not have a specified
resting position. For this reason before performing procedures on the
refrigerant circuit it must be set to a specified position (open or closed).
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; Refrigerant
Circuit; System Overview - Refrigerant Circuit.
- Depending on the design of the refrigerant circuit multiple shut-off
valves can be combined in one valve block (for example on the Audi Q7 e-tron).
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; Refrigerant
Circuit; System Overview - Refrigerant Circuit.
- The step motor is adapted and activated via the data wires (LIN Bus)
from the respective control module according to its component location.
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; Refrigerant
Circuit; System Overview - Refrigerant Circuit. Use the Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
Refrigerant Line with Inner Heat Exchanger
In this refrigerant pipe, the flowing fluid warm refrigerant
on the high pressure side is delivered into the low pressure
side as flowing, vapor, cold refrigerant to increase the
efficiency of the A/C system.
Note
This illustration shows a refrigerant pipe with an inner
heat exchanger that is installed in the Audi A4 from MY 2008 and
on the Audi A5 Coupe from MY 2008. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
A - Refrigerant line with inner heat exchanger
B - Channel inside the refrigerant pipe through with the warm
fluid refrigerant flows to the evaporator (refrigerant circuit
high pressure side)
C - Channel inside the refrigerant pipe in which the vapor of
cold refrigerant flow to the A/C compressor (refrigerant circuit
low pressure side)
Quick-Release Connections on Refrigerant Lines
WARNING
The quick-release coupling connectors may be
unlocked and opened only if the refrigerant circuit is
empty.
Note
- This illustration shows the quick-coupling connection with a
refrigerant pipe with an inner heat exchanger that is installed
in the Audi A4 from MY 2008 and on the Audi A5 Coupe from MY
2008. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- The retaining ring -A- must be
opened using, for example, the Air Conditioner Couplings Release
Tool -T40149- in order to remove the refrigerant line
-D-. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- The quick-release coupling connectors
-B- and -G- are to be
replaced after removing the refrigerant line with the respective
support ring -E- or
-H- and O-ring
-F- or -J-.
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual) and the Parts Catalog).
A - Retaining ring (inside the quick-release coupling connector,
high pressure side)
B - Quick-release coupling connector with retaining ring "high
pressure side"
C - Refrigerant line with an inner heat exchanger
D - Refrigerant line "high pressure side"
E - Support ring "high pressure side"
F - O-ring "high pressure side"
G - Quick-release coupling connector with retaining ring "low
pressure side"
H - Support ring "low pressure side"
J - O-ring "low pressure side"
Note
- There are different quick-release coupling versions
-A- and -D-.
The refrigerant lines -C-, for
example, can unlocked and removed using the Air Conditioner
Couplings Release Tool -T40149/1- in the same manner for both
versions of the quick-release couplings.
- The check pins on the -B-
quick-release couplings -A-
installed at SOP are visible -C-,
when the locked refrigerant line -C-
is pulled in the direction of arrow.
- Beginning with MY 2010, as a running change, the
quick-release coupling -D- and the
refrigerant line -C- are being
installed in the same manner as the quick-release coupling
-A-. If the refrigerant line
-C- is pulled in the direction of
arrow after assembling, the ring -E-
will come out of the quick-release coupling
-D- installed and will show that
the retaining ring -F- is
completely latched to the refrigerant line
-C-. Then the ring -E- can
be removed from the refrigerant line -C-.
READ NEXT:
These rings seal off the connection points between
individual components of the refrigerant circuit.
Only O-rings that are resistant to refrigerant R134a and
refrigerant oil must be installed. Make
Refrigerant Circuit with Expansion Valve and Evaporator
The following illustration shows only the principle of a
refrigerant circuit, the design of the refrigerant circuit in
the respective vehicle
General Information
Only valves and connections that are resistant to
refrigerant R134a and refrigerant oil must be installed.
Different connections (outer diameter) for high pressure and
low pre
SEE MORE:
Overview - Bumper Cover, Audi Q5
Caution
If the vehicle has lane change assistance, the lane change
assistance control module -J769-/-J770- must be recalibrated.
Refer to
→ Electrical Equipment; Rep. Gr.96; Lane Change Assistance; Lane
Change Assistance, Calibrating.
1
General Information
Caution
When handling refrigerant oil, pay attention to
local regulations.
Refrigerant oil mixes with the refrigerant (about 20-40%,
depending on compressor type and amount of refrigerant) and
circulates constantly in the system, lubricating the moving
parts.
Special