Audi A2 2001 - Page 173

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Possible Deviation From Specifi‐
cation
Possible Cause Of Fault Corrective Action
• High pressure normal or too
high
• Low pressure too high (see
graph)
• Required cooling output is not
attained.
• A/C compressor noise (partic‐
ularly after switch-on).
♦ To much refrigerant in the cir‐
cuit.
♦ Expansion valve or A/C com‐
pressor faulty.
– Extract refrigerant from refrigerant
circuit
• If quantity of refrigerant extracted
roughly corresponds to specified
capacity:
– Replace expansion valve
– Charge the refrigerant circuit
– Repeat test
• If quantity of refrigerant extracted
is substantially greater than speci‐
fied capacity:
– Charge the refrigerant circuit
– Repeat test
Note
If air conditioner operation is not OK when test is repeated, install
old expansion valve, clean refrigerant circuit (flush using refrig‐
erant R134a, refer to
⇒ “1.4.13 Refrigerant Circuit Flushing With Refrigerant R134a“,
page 32 or blow through using compressed air and nitrogen, refer
to
⇒ “1.4.12 Refrigerant Circuit Flushing With Compressed Air and
Nitrogen “, page 29 ). Then replace A/C compressor and reser‐
voir.
Possible Deviation From Specifi‐
cation
Possible Cause Of Fault Corrective Action
• High pressure only increases
slightly above pressure with
engine stopped
• Low pressure drops only slight‐
ly
• Required cooling output is not
attained
A/C compressor faulty. – Clean refrigerant circuit (flush with
refrigerant R134a, refer to
⇒ “1.4.13 Refrigerant Circuit
Flushing With Refrigerant R134a“,
page 32 or blow through with com‐
pressed air and nitrogen, refer to
⇒ “1.4.12 Refrigerant Circuit
Flushing With Compressed Air
and Nitrogen “, page 29 ).
– Replace A/C compressor and res‐
ervoir.
Possible Deviation From Specifica‐
tion
Possible Cause Of Fault Corrective Action
• High pressure normal
• Low pressure too low (see
graph)
• The required cooling perform‐
ance is obtained
Expansion valve or A/C compres‐
sor faulty.
– Replace expansion valve
– Charge the refrigerant circuit
– Repeat test
Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A2 2001 ➤ , A ...
Refrigerant R134a Servicing - Edition 01.2011
4. Diagnosis and Testing 169