Volkswagen Amarok 2011 Workshop Manual page 163

Amarok 2011 ➤ , Beetle 2012 ➤ , Bora 1999 ➤ , CC 2010 ➤ , CC 2012 ➤ , ...
Note
If the defect is in the air conditioner compressor regulating
♦
valve - N280- (the regulating valve is not activated, but the air
conditioner compressor still runs), it is not necessary to blow
through the refrigerant circuit. If this fault occurs, it is sufficient
to renew the air conditioner compressor (check the refrigerant
oil quantity in the air conditioner compressor).
Overfilling with refrigerant oil can occur if the refrigerant oil
♦
level was not checked after the air conditioner compressor
was renewed.
If the air conditioner compressor is not to be replaced, drain
♦
refrigerant oil from air conditioner compressor via the drain
plug. From the total amount of refrigerant oil, fill 50 g direct into
air conditioner compressor and fill remainder in refrigerant cir‐
cuit according to ⇒ vehicle-specific workshop manual .
If the expansion valve is defective (always closed or not open‐
♦
ing wide enough) the air conditioner compressor regulating
valve - N280- will be set to maximum power and the low-pres‐
sure value will fall to the diagram value or less (the air condi‐
tioner compressor is drawing the refrigerant out of the low-
pressure side). However, since no refrigerant can flow through
the expansion valve, the required cooling power is not deliv‐
ered, and it can be that the high-pressure value does not rise
at all or not enough, since no energy exchange is occurring.
Possible deviation from specifi‐
cation
• High pressure and low pres‐
sure are normal.
• The required cooling output is
not delivered.
• High pressure and low pres‐
sure are normal.
• The air conditioner compres‐
sor is noisy (especially imme‐
diately after being switched
on).
• The cooling power required is
delivered.
Air conditioning system with refrigerant R134a - Edition 10.2014
Possible cause of fault
♦ Actuation of air conditioner compressor reg‐
ulating valve - N280- is defective.
♦ Too much refrigerant oil in circuit.
♦ Too much refrigerant oil in circuit.
♦ Expansion valve defective.
Rectifying fault
– Check actuation of
air conditioner com‐
pressor regulating
valve - N280- .
– Purge (clean) refrig‐
erant circuit
⇒ page 67
– Drain refrigerant cir‐
cuit.
– Purge (clean) refrig‐
erant circuit
⇒ page 67
– Recharge refrigerant
circuit.
– Repeat check.
– Renew expansion
valve.
10. Checking pressures on vehicles
.
.
157