Skoda Citigo 2012 Workshop Manual page 91

Possible deviation from the specified value Possible cause of fault
• High pressure and low pressure is nor‐
mal at first, after a certain period of op‐
erating time:
– the high pressure increases above the
specified value,
– the low pressure drops to diagram value
or lower,
– the required cooling capacity is no lon‐
ger reached.
• High pressure and low pressure is nor‐
mal at first, after a longer period of op‐
erating time:
– if the low pressure drops below the
specified value (evaporator ices up).
Note
If problems arise due to humidity in the refrigerant circuit only
♦
after a longer operating time or only occasionally (the low
pressure drops below the specified value and the evaporator
ices up), it is adequate to replace the dessicator (the volume
of refrigerant oil must be adapted
⇒ "10.5 Replace catch pan and throttle/fluid reservoir",
page 94 ). Subsequently the refrigerant circuit must be evac‐
uated for at least 3 hours.
First of all, it is not required to clean the refrigerant circuit for
♦
this complaint (to flush with refrigerant R134a or to blow
through with compressed air and nitrogen), as normally only
a small amount of humidity is present in the system which can
be removed through a longer period of evacuation.
If this fault occurs, it can happen that the evaporator ices up
♦
although the volume of refrigerant in the circuit is O.K.
Due to a fault on the evaporator vent temperature sender -
♦
G263- the refrigerant circuit can also ice up. For this complaint,
also observe the measured value of this sender ⇒ Vehicle di‐
agnostic tester
Citigo 2012 ➤ , Fabia 2000 ➤ , Fabia II 2007 ➤ , Fabia II 2009 ➤ , Fab ...
Air conditioning system with refrigerant R134a - Edition 10.2014
♦ The actuation of the regu‐
lating valve for compressor
of air conditioning system -
N280- is incorrect.
♦ Humidity in the refrigerant
circuit.
9. Check the pressure in the refrigerant circuit (with the A/C service station)
Rectifying fault
– Check the actuation of the
regulating valve for com‐
pressor of air conditioning
system - N280- .
– Check expansion valve for
dirt or corrosion, replace if
necessary.
– Replace fluid reservoir with
dessicator or only dessica‐
tor (specifically designed
for vehicles) see notes.
– Evacuate the refrigerant cir‐
cuit for at least 3 hours.
– Repeat the test after refill‐
ing the circuit.
87