Determining Malfunction During Temperature Increase Downstream Of Evaporator In Front A/C Unit - Audi Q7 2007 Repair Manual

13.2.5 Determining Malfunction during Tem‐
perature Increase Downstream of Evap‐
orator in Front A/C Unit
– Clamp off both coolant hoses from engine to A/C unit (for ex‐
ample, Hose clamps up to 25 mm Diameter - 3094- in left front
wheel housing). Refer to
⇒ "6 Incorporation of the A/C System in Vehicle Coolant Cir‐
cuit", page 66 .
– Repeat cooling performance test. Refer to
⇒ "13 A/C Unit, Checking Cooling Output", page 215
♦ The measured value from both the left -G385- and right -G386- front upper body vent temperature sensor
(or the temperature of the air coming out of the vents in the instrument panel measured with a thermom‐
eter) differs less than 5° C from the measured value from the Evaporator Vent Temperature Sensor -
G263- . Use the Vehicle Diagnostic Tester via the "Guided Fault Finding" function.
Remove the hose clamps using the Hose Clamps - Up To 25
mm - 3094- at both coolant hoses.
Check the activation of the Left Temperature Door Motor -
V158- and of the Right Temperature Door Motor - V159- .
♦ Is the activation of Left Temperature Door Motor - V158- and of
Right Temperature Door Motor - V159- OK?
↓
No
↓
Repair the cause of malfunction. –
Use the Vehicle Diagnostic
Tester via the "Guided Fault
Finding" function.
Refer to Wiring diagrams, Trouble‐
shooting & Component locations.
↓
Repeat cooling performance –
test. Refer to
⇒ "13 A/C Unit, Checking Cool‐
ing Output", page 215
Heating, Ventilation and Air Conditioning - Edition 04.2013
↓
Yes
↓
–
↓
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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.
–
↓
Yes
↓
Check the operation of Left Temperature Door Motor - V158-
⇒ "9.9 Retaining plate with Left Footwell Door Motor V108 and Left
Temperature Door Motor V158 , Removing and Installing",
page 114 and of Right Temperature Door Motor - V159- . Refer to
⇒ "9.23 Retaining Plate with Control Motors V158 ( V159 ) and V109
( V108 ), Removing and Installing", page 153
Is the functionality of the Left Temperature door Motor - V158- and
of Right Temperature door Motor - V159- and door operation OK?
↓
Yes
↓
. Check function of respec‐ –
tive temperature door in
the A/C unit, for example
with the control motor re‐
moved.
↓
Repeat cooling performance test. Refer to
⇒ "13 A/C Unit, Checking Cooling Output", page 215
.
Check the correct installation of
sender with measured value devia‐
tion, as well as checking electrical
connections for contact resistance.
♦ On vehicles with "Basic" version A/C
system, only the measured value of
Evaporator Vent Temperature Sen‐
sor - G263- can be checked.
Eliminate cause of incorrect meas‐
ured value, replace defective send‐
–
↓
–
Repair the door actuation mecha‐
–
13. A/C Unit, Checking Cooling Output
Audi Q7 2007 ➤
↓
No
↓
–
↓
↓
–
er.
.
↓
No
↓
–
nism.
Refer to
.
↓
.
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