Low pressure gauge
A/C SYSTEM INSPECTION CHART - LOW PRESSURE GAUGE
| Condition | Possible Cause | Correction |
|---|---|---|
| Pressure is higher than acceptable range ("C" area) | Expansion valve malfunction (valve opens too wide) | Check expansion valve. |
| Compressor malfunction (Insufficient compression) | Check compressor. | |
| Pressure is lower than acceptable range ("D" area) | Insufficient refrigerant (Insufficient charge or leakage) | Check for leakage, repair if necessary and recharge. |
| Expansion valve malfunction (valve opens too narrow) | Check expansion valve. | |
| Clogged refrigerant passage (crashed pipe) | Repair or replace. |
- 11) Check inlet port temperature-to-outlet port temperature relationship using graph. For example, if A/C evaporator inlet port temperature is 30°C (86°F) and center ventilation louver temperature is 16°C (60.8°F), their crossing point is within acceptable range as shown in the graph in this case, cooling performance is satisfactory and proper.
- 12) If crossing point is out of acceptable range, diagnose trouble referring to the following table.