Audi 1999 TT, Repair Manual

Page: 96 / 199

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4.5 Condensation Water Drain Hose,
Checking
Note
♦
Only one condensation water drain hose is installed in this ve‐
hicle.
♦
On vehicles with heating (without A/C system), a sealing plug
is installed to seal the opening on the body center tunnel (no
condensation water hose is present).
♦
There is no valve and no door at the end of the condensation
water hose -C-.
♦ For complaints of moisture in passenger compartment, check
the following as well as condensation water drain:
– Plenum chamber water drain. Refer to
⇒ “4.10 Plenum Chamber Water Drain, Checking and Clean‐
ing“, page 100 .
– Plenum chamber cover and cover for fresh air intake housing
for correct installation and damage. Refer to
⇒ “5.12 Fresh Air Intake Cover“, page 142 .
– Dust and pollen filter for soiling and correct installation. Refer
to ⇒ “5.9 Dust and Pollen Filter“, page 138 .
– Forced air extraction vents in luggage compartment. Refer to
⇒ “4.9 Passenger Compartment Forced Air Extraction, Check‐
ing“, page 98 .
– Activation and function of back pressure door. Refer to
⇒ “2.10 Air Flow Door Motor V71 , Function“, page 62 and
recirculating air door
⇒ “5.8.5 Recirculation Door Motor V113 “, page 135 and Ve‐
hicle diagnosis, testing and information system -VAS5051B-
under "Guided Fault Finding".
♦ Also, if there is a complaint about moisture in the passenger
compartment that only occurs when the is A/C compressor is
switched on and under certain environmental conditions,
check the output temperature of air from the evaporator using
Vehicle diagnosis, testing and information system -
VAS5051B- under "Guided Fault Finding".
– Guided Fault Finding, in “read measured values block“, select
the measured value for evaporator vent temperature sensor -
G263- .
– Check output temperature of air at evaporator under condi‐
tions reported by customer or at the following setting on the
Climatronic control module -J255- , “Auto“ operating mode, A/
C compressor switched on (control light in
A/C
button lights
up), temperature setting “Cold“, middle fresh air blower speed
at a voltage of approximately 7 volts on the Fresh Air Blower
-V2- , fresh air mode (indicator light “recirculation button“ does
not light up) and open instrument panel vents, the air vent
temperature at the evaporator.
– If the evaporator vent temperature sensor -G263- measured
value is too low (colder than 0 ºC for a long period of time when
the ambient temperature is above 0 °C) or too high (even
though the A/C is working correctly, for example: higher than
10 °C), correct the cause for the difference. Follow the proce‐
dure for checking the cooling output. Refer to
⇒ “4.2 A/C Unit, Checking Cooling Output“, page 79 .
Audi TT 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 01.2011
92
Rep. Gr.87 - Air Conditioning