System Description

System Description




The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the system as shown.

This vehicle uses HFC-134a (R-134a) refrigerant which does not contain chlorofluorocarbons. Pay attention to the following service items:
- Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are not compatible.
- Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (DENSO ND-OIL8) designed for the R-134a compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in compressor failure.
- All A/C system parts (compressor, discharge line, suction line, evaporator, condenser, receiver/dryer, expansion valve, O-rings for joints) have to be designed for refrigerant R-134a. Do not exchange with R-12 parts.
- Use a halogen gas leak detector designed for refrigerant R-134a.
- R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a Recovery/Recycling/Charging System that is U.L. - listed and is certified to meet the requirements of SAE J2210 to service R-134a air conditioning system.
- Always recover the refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any A/C fitting.

A/C Pressure Switch

The A/C pressure switch consists of a High-Low pressure switch (A/C pressure switch A) and a Middle pressure switch (A/C pressure switch B).




- High-Low pressure switch
If the refrigerant pressure becomes too high (due to blockage), or too low (due to leakage), the A/C pressure switch sends a signal to the PCM to prevent the compressor from operating.




- Middle pressure switch
If the refrigerant pressure goes above or below 1,520 kPa (15.5 kgf/sq.cm, 220 psi), the A/C pressure switch sends a signal to the heater control panel or the climate control unit to change the speed of the condenser fan and radiator fan (High-Low).