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with respect to the correctness of information in this document. Copyright by AUDI AG.
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 (e.g.
radiator), pressure displayed with warm engine will be slightly
higher than that given for the respective ambient temperature.
♦
If pressure displayed is lower than specified in the table, check
the high pressure sensor signal. Refer to
⇒ “4.8 High Pressure Sensor G65 , Checking Pressure Sig‐
. If there is no fault on the high pressure sensor,
then there is not enough 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. In‐
form the workshop of the fault (insufficient refrigerant in the
circuit. Refer to ⇒ Refrigerant R134a Servicing; Rep. Gr. 00 ;
General Information .
Refrigerant circuit pressure OK
– Switch the A/C compressor on by selecting “Auto“ on the Cli‐
matronic control module -J255- (indicator lights in
AUTO
button
and
AC
button light up).
– Turn the Climatronic control module temperature rotary switch
to “cold“.
– Adjust air output direction via the air distribution rotary switch
on the Climatronic control module to “Instrument panel vents“.
– In “read measured values“ select the display group with the
measured values for controlling the A/C compressor regulator
valve -N280- and the measured value for the high pressure
sensor using -VAS5051B- under "Guided Fault Finding."
– Check display in display zones:
♦ A duty cycle greater than 30% is displayed (the A/C compres‐
sor regulator valve -N280- is controlled, A/C compressor is
switched on).
♦ A current greater than 0.3 A is displayed (current flows via A/
C compressor regulator valve, compressor is switched on)
Note
If no or very little current is displayed in display field, check ac‐
tuation of A/C compressor regulator valve. Refer to
⇒ “4.1 A/C Compressor Regulator Valve N280 , Checking Switch-
.
– The displayed refrigerant circuit pressure increases above the
value when the A/C compressor is switched off.
Audi TT 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 01.2011
82
Rep. Gr.87 - Air Conditioning