Volkswagen Polo Service & Repair Manual: Pressures, Checking
Note
Check cooling performance. The A/C system is functioning
correctly when the air flowing from the instrument panel vents
has a temperature of 70C or lower. |
Setting on Climatronic “LO”. |
Setting on A/C system “AC” on; “max”; “cold”. |
Connections with valve and service connections for measuring
and checking. |
– |
Connecting service station. Refer to
→ Chapter „Connecting Service Station“. |
– |
Take pressure gauge readings (two possible results). |
|
|
|
Ambient
Temperature in °C (°F) |
Pressure in
Refrigerant Circuit in bar (psi) Positive Pressure |
15 (59) |
3.9 (56.57) |
20 (68) |
4.7 (68.17) |
25 (77) |
5.6 (81.22) |
30 (86) |
6.7 (97.18) |
35 (95) |
7.8 (113.13) |
40 (104)
|
9.1 (131.98) |
45 (113) |
10.5 (152.28) |
Note
Temperature of refrigerant circuit components should be
equal to ambient temperature. |
Pressure will deviate from values in table if individual
components of refrigerant circuit are warmer or colder. |
At absolute pressure, 0 bar/psi corresponds to absolute
vacuum. Normal ambient pressure (positive pressure) corresponds
to 1 bar (14.5 psi) absolute pressure. 0 bar/psi pressure
corresponds to an absolute pressure of 1 bar (14.5 psi) on most
pressure gauges (indicated by 1 bar (14.5 psi) below 0). |
On vehicles with High Pressure Sensor -G65- with which the
measured pressure is displayed in the measured value block, the
measured pressure should correspond to the values in the table. |
The refrigerant circuit pressure is lower than indicated in
table |
Not enough refrigerant in refrigerant circuit |
– |
Determine refrigerant circuit leaks. Refer to
→ Chapter „Refrigerant Circuit, Tracing Leaks, with Electronic
Leak Detector -VAG1796-“. |
– |
Check the pressure relief valve. |
If pressure relief valve has responded: |
– |
Check the coolant fan activation. |
– |
Check refrigerant lines and hoses for cross-section
constrictions caused by inadequate bending radii. |
– |
Check refrigerant pipes and hoses for external damage. |
– |
If no malfunction is found, flush refrigerant circuit with
compressed air and nitrogen. |
The refrigerant circuit pressure is in line with table or is
higher |
– |
For vehicles with an electrically-driven A/C compressor,
switch on the ignition. |
WARNING
Hybrid vehicles have a high voltage system. Danger
of electrical shock! Inspect the high voltage components
visually before beginning. Follow the General Warnings.
Refer to
→ Hybrid Electric Equipment; Rep. Gr.93. |
|
– |
Set the A/C system to maximum cooling output. |
Note
If the low pressure switch was removed to connect the
service station, bridge the electrical connections in the
corresponding connector for the pressure measurement. |
A/C compressor is driven by the engine via A/C Clutch -N25-. |
The A/C Compressor Regulator Valve -N280- is activated by
the Climatronic Control Module -J255-. |
If A/C compressor is not driven with the engine running or
regulating valve is not actuated: |
– |
Determine and eliminate cause e.g. by checking air
conditioner DTC memory. |
– |
Observe test conditions. |
– |
Check the A/C Clutch -N25- voltage supply. If it is OK,
repair the A/C clutch. |
– |
Check activation of A/C Compressor Regulator Valve -N280-. |
|
Note
Check cooling performance. The A/C system is functioning
correctly when the air flowing from the instrument panel vents
has a temperature of ...
Note
Check cooling performance. The A/C system is functioning
correctly when the air flowing from the instrument panel vents
has a temperature of ...
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