Diagnosis of Malfunction in Automotive Refrigeration Cycle
1.Importance of checking pressure
Checking the refrigerant pressure while the air conditioning is functioning allows you to assume the trouble area or the cause. Therefore, it is important to confirm the appropriate value and to diagnose the trouble.
2.Trouble seeking by using manifold gauge
When performing the trouble diagnosis by using a manifold gauge, follow the conditions below.
Engine coolant temperature: After warm-up
All doors: Fully opened
Airflow selector: “FACE”
Air inlet selector: “RECIRC”
Engine speed: 1,500 rpm (R-134a), 2,000 rpm (R-12)
Blower speed selector: HI
Temperature selector: MAX. COOL
A/C switch: ON
A/C inlet temperature: 30 to 35°C (86 to 95°F)
NOTICE:
For the vehicle with EPR, since the low-pressure side is controlled with EPR, abnormal values may not be indicated directly on the gauge pressure.
