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.
– Read the measured values block with the display for the po‐
sition of the Left Temperature Door Motor -V158- . Refer to -
VAS5051B- in "Guided Fault Finding".
– Measure temperature of air flowing out of left and right instru‐
ment panel vents.
Target values:
♦ It will display that the Left Temperature Door Motor is at the
“bottom“ (“cold“).
♦ The temperature of the air coming out of the left and right in‐
strument panel vents decreases within 5 minutes to a value
that is a maximum of 15 °C higher than the previously meas‐
ured environmental temperature.
If the specified values are not reached, check the following:
♦ If the required heat output is not reached
– Ventilation of coolant circuit. Refer to⇒ Engine Mechanical;
Rep. Gr. 19 ; General Information .
– The integration of the heater core in the coolant circuit, refer
to⇒ Engine Mechanical; Rep. Gr. 19 ; General Information .
– Activation and function of Left Temperature Door Motor -V158-
using -VAS5051B- in "Guided Fault Finding".
– The foam seal on the heater core. Refer to
⇒ “5.14 Heater Core“, page 144
.
– Function of temperature doors in air distribution housing. Re‐
fer to
⇒ “2.14 Air Guide In Air Distribution Housing“, page 69
.
– Coolant regulator (engine coolant may not warm properly if
regulator is malfunctioning). Refer to⇒ Engine Mechanical;
Rep. Gr. 19 ; Description and Operation .
– The delivery of the engine coolant pump. Refer to⇒ Engine
Mechanical; Rep. Gr. 19 ; Description and Operation .
♦ If the air coming out of the vents is too warm when it is set to
“Cold“
– Activation and function of Left Temperature Door Motor -V158-
using -VAS5051B- in "Guided Fault Finding".
– Function of temperature doors in air distribution housing. Re‐
fer to
.
– The plenum chamber and seal between engine compartment
and plenum chamber.
Audi TT 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 01.2011
3. Diagnosis and Testing
15