Audi Air conditioning 2003 A8 Workshop Manual page 137

• Measured values for left vent temperature sender -G150- and right vent temperature sender -G151-
deviate by less than 3 °C from measured value for evaporator output temperature sender -G263- ? ⇒
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
Detach the hose clamps up to dia. 40 mm -VAS
3093- or the hose clamps up to dia. 25 mm -
VAS 3094- at the two coolant hoses.
Check actuation of the heat regulation valves -
N175- , -N176- and the coolant circulation
pump -V50-
• Actuation of heat regulation valves and coolant circulation pump OK?
Connect the test box -V.A.G 1598/19- to the wiring harness to the
front operating and display unit ⇒ "Guided fault-finding" function of
vehicle diagnostic, testing and information system VAS 5051.
Perform electrical checks for left heat regulation valve -N175- , right
heat regulation valve -N176- and coolant circulation pump -V50- ⇒
"Guided fault-finding" function of vehicle diagnostic, testing and in‐
• Operation of left heat regulation valve -N175- , right heat regulation
valve -N176- and coolant circulation pump -V50- OK?
↓
yes
↓
Replace the front operat‐ –
ing and display unit
⇒ page 80 and
⇒ page 80
↓
Repeat the cooling output test
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↓
yes
↓
–
↓
–
⇒ page 131
↓
yes
↓
–
↓
–
formation system VAS 5051. .
↓
Replace the pump valve unit
.
–
Air conditioning - Edition 09.2010
Check the sender supplying the deviating measured
value for correct installation, as well as the electrical
connections for contact resistance ⇒ "Guided fault-
finding" function of vehicle diagnostic, testing and
information system VAS 5051.
– Eliminate the cause of the incorrect measured value
and replace the defective sender ⇒ "Guided fault-
finding" function of vehicle diagnostic, testing and
information system VAS 5051.
↓
no
↓
–
⇒ page 58 .
↓
⇒ page 122 .
11. Checking cooling output of air conditioner
Audi A8 2003 ➤
↓
no
↓
–
↓
⇒ page 131
↓
no
↓
– Eliminate cause of malfunction
⇒ "Guided fault-finding" func‐
tion of vehicle diagnostic, test‐
ing and information system
VAS 5051.
⇒ Current flow diagrams, Electri‐
cal fault finding and Fitting loca‐
tions
↓
Repeat the cooling output test –
⇒ page 122 .
131