Function Inspection

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Courtesy of SUBARU OF AMERICA, INC.

1. For relative humidity, when the dry bulb temperature of the wet-and-dry-bulb thermometer at the inlet opening is 25°C {77°F} and the wet bulb temperature is 19.5°C {67.1°F}, the intersection of the broken lines in the figure is the relative humidity. In this case, it is 60%.

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Criteria: The value must be within the shaded area of the diagram.

1. To obtain the cooling performance using the standard performance table, an example when the difference of temperatures between the inlet opening and the outlet opening is 17°C {30.6°F} and the relative humidity is 60% is shown below.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

1. Attach the air conditioner tool set.
2. Set the vehicle to the following conditions. [*2]

   Item	Conditions
   Engine	After warming-up
   Door	Full open
   A/C switch	ON
   RECIRC switch	Recirculation
   Setting temperature	LO
   Blower speed	HI
   Air conditioner inlet opening temperature	30 to 35°C {86 to 95°F}

3. Check the gauge value in [*2].
   1. At normal condition

      Standard value: 0.13 to 0.20 MPa (1.3 to 2.0 kgf/cm² ) (Low pressure side)

      1.47 to 1.67 MPa (15 to 17 kgf/cm² ) (High pressure side)

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      NOTE: The illustration indicates the gauge at normal charge level of refrigerant gas.
   2. In malfunction
      1. Example: During operation of the air conditioner, the pressure at the low pressure side becomes vacuum or normal.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	It becomes cold or not cold cyclically.
         Cause	Moisture in the cooling system is frozen at the cooler expansion valve. The refrigerant does not circulate temporarily. After ice is melted, normal operation is recovered.
         Diagnosis	The cooler drier is over-saturated. Moisture of the cooling system is frozen at the expansion valve and it blocks circulation of the refrigerant gas.
         Corrective action	Replace the cooler dryer. Remove moisture in the cycle by repeating air release. Inject appropriate level of new refrigerant gas.

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         NOTE: The illustration indicates the gauge condition of moisture inclusion in the cooling system.
      2. Example: Both high and low pressure sides are low.

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         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Poor cooling performance Cooling performance is not sufficient.
         Cause	A part of the cooling system has gas leak.
         Diagnosis	Refrigerant gas is insufficient. Leak of refrigerant gas
         Corrective action	Check for gas leak. Repair it if necessary. Inject appropriate level of new refrigerant gas. If the pressure value is close to 0 when connected to the gauge, check for the leak area. After repair, perform vacuuming.

         NOTE: The illustration indicates the gauge condition of poor cooling.
      3. Example: The pressures at both low and high pressure sides are low and the pipe connected from the cooler condenser ASSY to the air conditioner unit has condensation.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Poor cooling performance
         Cause	Dust in the cooler condenser core blocks flow of refrigerant.
         Diagnosis	Clogged cooler condenser core
         Corrective action	Replace the cooler condenser ASSY.

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         NOTE: The illustration indicates the gauge condition of poor refrigerant gas performance.
      4. Example: Pressures at both low and high pressure sides are low and the pipe before and after the cooler condenser core and the cooler expansion valve has fogging or condensation.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Poor cooling (it may work in cases)
         Cause	Flow of the refrigerant gas is blocked by moisture or dust of the cooling system. Flow of the refrigerant gas is blocked by leak of the refrigerant gas from the cooler expansion valve.
         Diagnosis	Refrigerant gas does not circulate.
         Corrective action	Check the cooler expansion valve. Remove dust in the cooler expansion valve with an air gun. Replace the cooler condenser ASSY. After vacuuming, inject new refrigerant gas to the appropriate level. If leak of the refrigerant gas from the cooler expansion valve is found, replace the cooler expansion valve.

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         NOTE: The illustration indicates the gauge for no circulation of the refrigerant gas.
      5. Example: Both high and low pressure sides are too high.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Poor cooling performance
         Cause	Flow of the refrigerant gas is blocked by moisture or dust of the cooling system. Flow of the refrigerant gas is blocked by leak of the refrigerant gas from the cooler expansion valve.
         Diagnosis	Excessive refrigerant Cooling of the cooler condenser core is insufficient.
         Corrective action	Clean the cooler condenser core fin. Check operation of the cooling fan. Check the refrigerant level and inject the refrigerant to the appropriate level.

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         NOTE: The illustration indicates the gauge condition of excess refrigerant gas or insufficient cooling of the cooler condenser core.
      6. Example: Pressures at both low and high pressure sides are high and the low pressure pipe is too hot to be touched.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Air conditioner does not function.
         Cause	Air inside the cooling system
         Diagnosis	Air is included inside the cooling system. Insufficient vacuuming
         Corrective action	Check if the compressor oil is contaminated or insufficient. After vacuuming, inject new refrigerant gas.

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         NOTE:

         • CAUTION: The gauge indicates a value when the cooling system is opened without vacuuming for injection of the refrigerant.
         • The illustration indicates the gauge condition of air inclusion in the cooling system.
      7. Example: Pressures at both low and high pressure sides are high and the low pressure side has fogging or condensation.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Poor cooling performance
         Cause	Problems on cooler expansion valve
         Diagnosis	Excessive refrigerant of low pressure pipe Excessive opening of cooler expansion valve
         Corrective action	Replace the cooler expansion valve.

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         NOTE: The illustration indicates the gauge of improper cooler expansion valve.
      8. Example: Pressure at the low pressure side is high and pressure at the high pressure side is low.
         SYMPTOM DESCRIPTION - MEASUREMENT RESULT
         
         

         Symptoms	Air conditioner does not function.
         Cause	Compression leak in cooler compressor ASSY
         Diagnosis	Poor compression Leak from valve or damage to sliding part
         Corrective action	Repair or replace the cooler compressor ASSY.

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         NOTE: The illustration indicates the gauge of poor compression of the cooler compressor ASSY.