Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Note
♦
If the required values are not reached, compare the displayed
measured values for the left footwell vent temperature sensor
and right footwell vent temperature sensor with each other:
♦
If the measured value from the left footwell vent temperature
sensor or the right footwell vent temperature sensor is OK,
check the actuation and the function of the left temperature
door motor -V158- and the right temperature door motor -
V159- . Refer to
⇒ “4.2.4 Temperature Increase Downstream from Evaporator,
Determining Malfunction“, page 88
⇒ “4.6 Heating Performance Of A/C System, Checking“, page
and -VAS5051B- in "Guided Fault Finding."
♦
If the measured value from the left footwell vent temperature
sensor and/or from the right footwell vent temperature sensor
is lower than the measured value from the evaporator vent
temperature sensor -G263- . Make sure the evaporator vent
temperature sensor, left footwell vent temperature sensor and
right footwell vent temperature sensor are installed correctly
and check their electrical connectors for contact resistance.
Replace the faulty sensor if necessary. Refer to -VAS5051B-
in "Guided Fault Finding."
♦
If there is no fault found on the left footwell vent temperature
sensor -G261- , right footwell vent temperature sensor -G262-
and evaporator vent temperature sensor -G263- as well as on
the left temperature door motor -V158- and right temperature
door motor -V159- , then determine the malfunction with tem‐
perature increase downstream of the evaporator. Refer to
⇒ “4.2.4 Temperature Increase Downstream from Evaporator,
Determining Malfunction“, page 88
♦
The air temperature flowing out of the “center“ instrument pan‐
el vents. A commercially available thermometer can also be
used.
♦
If there is a complaint of a different temperature of air from
vents in A/C system regulated mode as at the same setting in
regulated mode, the causes for this may be temperature doors
in the heating and A/C unit is not opening or closing complete‐
ly, or is not quite reaching its end position). Refer to
⇒ “2.1 Air Routing and Distribution in Passenger Compart‐
and -VAS5051B- in "Guided Fault Finding."
There is air in the heater core (fluctuating flow through heater
core and heat is not distributed uniformly). Refer to
⇒ “4.6 Heating Performance Of A/C System, Checking“, page
. A foam seal has loosened during installation of heater
core and air may flow past at heater core. The A/C system
refrigerant circuit is not filled with the correct quantity of refrig‐
erant.
4.2.3
Determining Malfunction if Specified
Values Are Not Obtained
The required cooling output is not reached during the cooling out‐
⇒ “4.2.2 Cooling Output, Checking“, page 81
.
Audi TT 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 01.2011
4. Diagnosis and Testing
85