Audi Q7 2007 Repair Manual page 243

Note
Depending on version of Instrument Cluster Control Module -
♦
J285- , a coolant temperature of, for example, 90° C (194° F)
is always displayed in instrument cluster within a certain tem‐
perature range of coolant temperature (engine temperature),
the temperature displayed can therefore deviate from the ac‐
tual coolant temperature.
If engine temperature deviation is greater than 20° C (68° F)
♦
or greater than 10° C (50° F) between measured values at left
and right sides, check ventilation of heater core (refer to
⇒ "7 Coolant Circuit, Bleeding", page 78
cuit) and activation and function of temperature door control
motors. Refer to
⇒ "9.9 Retaining plate with Left Footwell Door Motor V108 and
Left Temperature Door Motor V158 , Removing and Installing",
page 114 ,
⇒ "9.23 Retaining Plate with Control Motors V158 ( V159 ) and
V109 ( V108 ), Removing and Installing", page 153
the Vehicle Diagnostic Tester via the "Guided Fault Finding"
function.
– Increase engine speed up to approximately 3,000 RPM in
several stages.
– Observe the display in the display fields with the measured
values from the left -G385- and right -G386- front upper body
vent temperature sensors, or, measure of air flowing out of
instrument panel vents on left and right sides in alternation
using a thermometer. The displayed or measured temperature
must not change significantly (or must rise or fall along with
engine temperature).
Note
If the displayed or measured temperature changes by more than
approximately 10° C (50° F) or is lower in one speed range, check
incorporation of A/C system into cooling circuit (refer to
⇒ "6 Incorporation of the A/C System in Vehicle Coolant Circuit",
page 66 ) and incorporation and activation of Coolant Recircula‐
tion Pump - V50- ( Water Pump - V36- ). Use the Vehicle Diag‐
nostic Tester via the "Guided Fault Finding" function.
– Switch engine off and then ignition on again.
– Set an intermediate fresh air blower speed on the Climatronic
Control Module - J255- front A/C control head.
Note
At maximum fresh air blower speed, the delivery rate of Coolant
Recirculation Pump - V50- ( Water Pump - V36- ) is no longer
sufficient and the outlet temperature sinks relatively quickly to a
value of approximately 40° C (104° F).
– Perform Guided Fault Finding on the A/C system and read the
display in the measured values block display group with the
measured values from the left -G385- and right -G386- front
upper body vent temperature sensors or measure temperature
of air flowing out of instrument panel vents on left and right
sides.
– While doing this, observe the display fields with the measured
values from the left -G385- and right -G386- front upper body
vent temperature sensors, or the alternating measured values
Heating, Ventilation and Air Conditioning - Edition 04.2013
) (bleed cooling cir‐
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and use
14. Heating Performance of A/C System, Checking
Audi Q7 2007 ➤
237