Audi Q3: Cooling Output, Checking, Manual Climate Control System
Procedure
- The requirements for testing the cooling capacity are
fulfilled. Refer to
→ Chapter "A/C Cooling Output, Testing Requirements".
- Measure the ambient temperature (must be warmer than 15 ºC
(59 ºF) ).
- Close the doors, the engine hood, the windows, the sunroof
and the rear lid.
- Open all instrument panel vents.
- Start the engine.
- Switch off the A/C compressor. The indicator lamp in the
AC or A/C
button -2- does not illuminate.
- "Read measured values", Air Conditioning (A/C) system using
the Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
Checking
- Read the actuation of the A/C Compressor Regulator Valve
-N280-.
- The activation of the A/C compressor is switched off and 0%
is displayed.
- Read the measured value for the High Pressure Sensor -G65-.
- The pressure in the refrigerant circuit is same as the
measured outside temperature or greater than the value in the
chart.
Note
- At absolute pressure, 0 bar corresponds to absolute vacuum.
Normal ambient pressure equals approximately 1.0 bar (14.5 psi)
absolute pressure and 0 bar pressure. On the scales of most
pressure gauges, 0 bar pressure corresponds to an absolute
pressure of one bar (can be seen from -1 mark below 0).
- Depending on the version of the A/C Control Module -J301-,
only integer values may be displayed as measured values. If the
measured pressure is between two values, the display alternates
between the two values.
- Pressure in refrigerant circuit is governed by ambient
temperature. On account of heat given off by components (for
example, the radiator), pressure displayed with warm engine will
be slightly higher than that given for the respective ambient
temperature.
If pressure displayed is below that indicated in table:
- Check the signal of the High Pressure Sensor -G65-. Refer to
Vehicle Diagnostic Tester in the "Guided Fault Finding" and
→ Chapter "High Pressure Sensor -G65-, Checking Pressure Signal".
- If no fault can be determined at the High Pressure Sensor
-G65-, then there is not enough refrigerant in the circuit.
Bring the vehicle to a workshop that has the necessary tools and
in which the work can be performed accordingly by qualified
personnel. Refer to
→ Refrigerant R134a Servicing; Rep. Gr.87; A/C System, General
Information (Refrigerant R134a, Servicing; A/C
System, General Information).
If the Refrigerant Circuit Pressure is OK.
Adjust the following settings on the A/C Control Module
-J301- control head:
- Turn the temperature knob -1-
to the "cold" stop.
- Turn the air distribution knob -4-
to the "instrument panel vent" stop.
- The A/C compressor is on - the indicator lamp in the
AC or A/C
button -2- illuminates.
- The recirculating air mode is on - the indicator lamp in the
recirculation button
-3- illuminates.
- Turn the knob -5- for the fresh
air blower to level "4".
- "Read measured values", A/C system using the Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
- Check the display in the display fields:
- The current calculated by the A/C Control Module -J301-,
which flows via the A/C Compressor Regulator Valve -N280- is
greater than 0.3 Amps (the A/C compressor is switched on)
- The displayed pressure increases above the value when the
compressor is switched off.
Note
- If the pressure displayed does not change and yet the A/C
compressor activation is OK, make sure the calculated current is
actually flowing via the A/C Compressor Regulator Valve -N280-
and that the A/C compressor is actually being driven. There is a
fault in the refrigerant circuit If the current is flowing via
the A/C Compressor Regulator Valve A/C Compressor Regulator
Valve -N280- and the A/C compressor is being driven. Bring the
vehicle to a workshop that has the necessary tools and in which
the work can be performed accordingly by qualified personnel.
Refer to
→ Refrigerant R134a, Servicing; Rep. Gr.87; A/C System, General
Information (Refrigerant R134a, Servicing; A/C
System, General Information). If the A/C compressor control is
not OK, then inform the workshop of the problem at hand.
- The A/C Control Module -J301- actuates the A/C Compressor
Regulator Valve -N280- so that the air temperature reaches the
specified value downstream of the evaporator (approximately 2º
to 5 ºC (36º to 41 ºF) ).
- After vehicle start, a value greater than 0.55 A is
displayed for the activation of the A/C Compressor Regulator
Valve -N280- depending on the measured temperature, the engine
speed and the vehicle voltage. As soon as the temperature
measured by the Evaporator Vent Temperature Sensor -G263- nears
the specified value, the activation, and thus the compressor
output, is reduced.
- Under certain operating conditions, moisture in the
refrigerant circuit can lead to ice build-up on the A/C
Compressor Regulator Valve -N280- (and on the expansion valve).
A/C compressor regulation is reduced by this ice build-up. The
evaporator is cooled too intensely and freezes. The ice on the
evaporator may cause various customer concerns. Refer to
→ Chapter "Ice Formation on Evaporator, Localizing Malfunction".
- If no or very little current is displayed in the measured
values for the A/C Compressor Regulator Valve -N280- actuation,
check the actuation of the A/C Compressor Regulator Valve
-N280-. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
- Certain functions on the A/C Compressor Regulator Valve
-N280- (for example, a stuck valve or a disruption in the coil)
can lead to a complaint regarding the A/C compressor (A/C system
doesn't cool, the evaporator ices over, etc.). If the cause is
with the A/C Compressor Regulator Valve -N280- (and not the A/C
compressor itself), the A/C compressor can be serviced by
replacing the A/C Compressor Regulator Valve -N280-. Refer to
→ Refrigerant R134a Servicing; Rep. Gr.87; Refrigerant Circuit
Components, Replacing (Refrigerant R134a, Servicing;
Refrigerant Circuit Components, Replacing).
- The A/C Compressor Regulator Valve -N280- is not available
as a replacement part for all A/C compressors. If the A/C
Compressor Regulator Valve -N280- is not available as an
individual A/C compressor part (different versions), then the
entire A/C compressor must be replaced. Refer to the Parts
Catalog.
READ NEXT:
Procedure
The requirements for testing the cooling capacity are
fulfilled. Refer to
→ Chapter "A/C Cooling Output, Testing Requirements".
- Measure the ambient temperature (must
Refrigerant is never to be allowed to escape into the
atmosphere, but rather it is to be extracted from the
refrigerant circuit using an Air Conditioning (A/C) service
station. The drained refri
Actuator Information
Caution
A/C system (heater) malfunctions
A/C system malfunctions can occur if the actuator
and/or the corresponding connectors are switched.
A/C system (heater
SEE MORE:
Special tools and workshop equipment
required
Hose Clamps - Up To 25mm -3094-
Engine Bung Set -VAS6122-
Compressed air gun, commercially available
Removing
WARNING
There is a risk of scalding from hot steam and
coolant.
The coolant system is under pressure when the eng
WARNING
Risk of injury. Follow all warning messages and
safety precautions. Refer to
→ Chapter "Warnings and Safety Precautions".
WARNING
Do not check or charge a Battery -A- when the visual
indicator has "no color or is
bright yellow". Jump starting must not be