Audi Q7 2007 Repair Manual page 224

Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
Note
Depending on the version of the Climatronic Control Module -
J255- front A/C control head, it is possible to recognize if "Econ"
is on if the indicator lamp in the
button off.
– Start the engine.
– Initiate Guided Fault Finding of the Climatronic Control Module
- J255- front A/C control head of A/C system. Use the Vehicle
Diagnostic Tester via the "Guided Fault Finding" function.
– Select "Read measuring value block" function and read out
values in the following display groups and use the Vehicle Di‐
agnostic Tester via the "Guided Fault Finding" function.
♦ The compressor activation via the A/C Compressor Regulator
Valve - N280- is switched off (the compressor is switched off
and 0% is shown in the display field).
♦ The pressure in the refrigerant circuit determined by the High
Pressure Sensor - G65- is the same or greater than the value
in the table at the measured ambient temperature.
Ambient Temperature
15° C (59 °F)
20° C (68 °F)
25° C (77 °F)
30° C (86 °F)
35° C (95 °F)
Note
In terms of absolute pressure, 0 bar corresponds to an abso‐
♦
lute vacuum. Normal ambient pressure equals approximately
1 bar absolute pressure. On the scales of most pressure
gauges, 0 bar corresponds to an absolute pressure of one bar
(can be seen from -1 mark below 0).
At this time, only integer values are displayed for this vehicle
♦
in the measuring value block, if the pressure measured lies
between two values the display alternates between the two
values.
♦ Pressure in refrigerant circuit is governed by ambient temper‐
ature. On account of heat given off by components (such as
the radiator), pressure displayed with warm engine will be
slightly higher than that given for the respective ambient tem‐
perature.
If the pressure displayed is lower than specified in the table,
♦
check the High Pressure Sensor - G65- signal. Refer to
⇒ "3.4 High Pressure Sensor G65 , Checking Pressure Sig‐
nal", page 19 . If no malfunction can be detected at the High
Pressure Sensor - G65- , there is insufficient refrigerant in the
circuit, bring 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 pressure in refrigerant circuit is OK:
– Turn on the compressor, to do this select operating mode "Au‐
to" on the Climatronic Control Module - J255- front A/C control
218
Rep. Gr.87 - Air Conditioning
button is on and in the
Econ
Pressure Display
4.0 bar (43.5 psi)
5.0 bar (58 psi)
6.0 bar (72.5 psi)
7.0 bar (87 psi)
8.0 bar (101.5 psi)
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with respect to the correctness of information in this document. Copyright by AUDI AG.
AC