Audi Air conditioning 2003 A8 Workshop Manual page 139

testing and information system VAS 5051 (for auxiliary heat‐
er).
12.1.1 Test requirements
♦ Coolant circuit bled in specified manner: ⇒ Engine, mechan‐
ics; Rep. gr. 19
♦ All air ducts, covers and seals OK and properly fitted
♦ Air flow through dust and pollen filter not impaired by dirt
♦ Engine warm
♦ Battery -A- (vehicle battery) OK and adequately charged (to
prevent energy management control unit -J644- switching off
front operating and display unit, Climatronic control unit -J255-
during test)
♦ Fault memory of front operating and display unit, Climatronic
control unit -J255- (and rear Climatronic operating and display
unit -E265- ) interrogated and erased, basic setting performed
and encoding of front operating and display unit, Climatronic
control unit -J255- checked ⇒ "Guided fault-finding" function
of vehicle diagnostic, testing and information system VAS
5051
♦ Adaption of front operating and display unit, Climatronic con‐
trol unit -J255- (and rear Climatronic operating and display unit
-E265- ) checked ⇒ "Guided fault-finding" function of vehicle
diagnostic, testing and information system VAS 5051.
♦ Vehicle not exposed to sunlight
12.1.2 Checking
Special tools and workshop equipment required
♦ Battery charger, 60 A -VAS 5904-
– Close the front lid.
– Close the doors, windows and sun roof.
– Start the engine and let it run for a few minutes at maximum
cooling output (compressor ON, „LO" temperature setting for
left and right side).
– Switch off ignition.
– With the ignition switched off, connect up the vehicle diagnos‐
tic, testing and information system -VAS 5051 A- with the
diagnostic cable -VAS 5051/5A- to the 16-pin diagnostic sock‐
et in the vehicle and select air conditioner/heater electronics
⇒ "Guided fault-finding" function of vehicle diagnostic, testing
and information system VAS 5051.
– Switch on ignition.
The front operating and display unit starts up, the coolant circu‐
lation pump -V50- is not actuated and does not run, the left heat
regulation valve -N175- and the right heat regulation valve -N176-
are actuated and closed.
– Read out the measured value block. There must not be any
deactivation requests from the energy management control
unit -J644- ⇒ "Guided fault-finding" function of vehicle diag‐
nostic, testing and information system VAS 5051.
– Read out the measured values for the left vent temperature
sender -G150- and the right vent temperature sender -G151-
⇒ "Guided fault-finding" function of vehicle diagnostic, testing
and information system VAS 5051.
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with respect to the correctness of information in this document. Copyright by AUDI AG.
12. Checking heat output of air conditioner and operation of pump valve unit
Audi A8 2003 ➤
Air conditioning - Edition 09.2010
133