New Beetle L4-1.8L Turbo (AWV) (2005)
Expansion Valve: Testing and Inspection
Expansion Valve and Receiver (Without Internally Regulated Compressor), Checking
Expansion Valve and Receiver (Without Internally Regulated Compressor), Checking
Test requirements
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Radiator and condenser clean (clean if necessary)
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Ribbed belt for A/C compressor and generator is correctly tensioned.
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All air ducts, covers and seals OK and properly installed
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Flaps reach their end positions.
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Engine at normal operating temperature
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Evaporator and heater not drawing in secondary air at maximum fresh-air blower speed.
Note the following points when engine is running and A/C system set to maximum cooling output:
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Fresh air blower running.
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Coolant fan in operation or is switched on.
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Recirculating/fresh air door in "recirculating air" position.
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Ambient temperature greater than 15 degree C.
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A/C Evaporator Temperature Switch E33 is correctly installed and its switching temperatures are OK.
Checking
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Switch ignition off.
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Connect pressure gauge set (service station).
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Take pressure gauge reading. Two results A and B can be displayed.
Ambient temperature
Pressure in refrigerant circuit
in degrees Celsius
in bar positive pressure
+15 degree C
3.9
+20 degree C
4.7
+30 degree C
6.7
+40 degree C
9.1
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A - Pressure in refrigerant circuit is lower than indicated in the table, not enough refrigerant in circuit.
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Localize leak using leak detector.
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Pressure relief valve opened, check activation for coolant fan according to wiring diagram.
Check for constricted refrigerant pipe and hose cross-sections caused by inadequate bending radii or external damage. If no malfunction can be
found, flush refrigerant circuit.
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B - Pressure in refrigerant circuit in line with table or higher:
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Start engine.
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Set air conditioning system to maximum cooling output.
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Open doors.
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Open air vents in instrument panel.
Engine drives A/C compressor by ribbed belt via A/C Clutch.
NOTE:
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If A/C compressor is not being driven, check voltage supply for A/C Clutch N25 according to wiring diagram.
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If voltage supply is OK, repair A/C clutch.
If A/C compressor is driven, check refrigerant circuit:
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Set engine speed to 2000 RPM.
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Observe pressure gauge set:
Specified values
High pressure side:
Increasing from pressure with engine switched off up to maximum 20 bar positive pressure.
Low pressure side:
Decreasing from pressure with engine switched off up to 1.3 bar positive pressure.