Trouble Diagnosis for Abnormal Pressure
WARNING: This page is about a different car, the 2010 Suzuki Kizashi. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Normal pressure values on high side and low side in the following table are measured when the ambient temperature is about 30 °C (86 °F). As normal pressure values on high side and low side vary depending on the ambient temperature, be sure to perform the following steps first when diagnosing troubles.
- Measure the ambient temperature and using that value, read the normal value from the graph given in Step 9 of A/C System Performance Inspection.
- Put that value in place of the normal pressure in the following table.
TROUBLE DIAGNOSIS CHART
| Condition | Possible cause | Correction | ||
|---|---|---|---|---|
| Manifold gauge kPa (kgf/cm2 ) (psi) | Detail | |||
| Lo | Hi | |||
| 261 - 382 (2.7 - 3.9) (37.8 - 55.4) |
1300 - 1580 (13.2 - 16.1) (188 - 229) |
Normal condition | - | - |
| Negative pressure | 500 - 600 (5.1 - 6.1) (72.5 - 87.0) |
The low pressure side reads a negative pressure, and the high pressure side reads an extremely low pressure. Presence of frost around tubing to and from condenser assembly and expansion valve. | Dust particles or water droplets are either stuck or frozen inside expansion valve, preventing the refrigerant from flowing. | Replace expansion valve. Replace condenser assembly. Evacuate the A/C system and recharge with fresh refrigerant. |
| Normal: 261 - 382 (2.7 - 3.9) (37.8 - 55.4) ↑ ↓ Abnormal: Negative pressure |
Normal: 1300 - 1580 (13.2 - 16.1) (188 - 229) ↑ ↓ Abnormal: 700 - 1000 (7.1 - 10.2) (102 - 145) |
During A/C operation, the low pressure side sometimes indicates negative pressure, and sometimes normal pressure. Also high pressure side reading fluctuates between the abnormal and normal pressure. | Expansion valve is frozen due to moisture in the system, and temporarily shuts off the refrigeration cycle. | Replace expansion valve. Replace condenser assembly. Evacuate A/C system and recharge with fresh refrigerant. |
| 50 - 150 (0.5 - 1.5) (7.25 - 21.8) |
700 - 1000 (7.1 - 10.2) (102 - 145) |
Both low and high pressure sides indicate low readings. Output air is slightly cold. |
Insufficient refrigerant in system (Refrigerant leaking). | Using leak detector, check for leaks and repair if necessary. Recharge refrigerant to a specified amount. If the pressure reading is almost 0 when the manifold gauges are attached, check for any leaks, repair them, and evacuate the system. |
| 400 - 600 (4.1 - 6.1) (58.0 - 87.0) |
Pressure on low pressure side is high. Pressure on high pressure side is low. Both pressures become equal, right after A/C is turned OFF. |
Internal leak in A/C compressor. | Inspect A/C compressor and repair or replace if necessary. | |
| 400 - 450 (4.1 - 4.6) (58.0 - 65.3) |
2000 - 2500 (20.4 - 25.5) (290 - 363) | High pressure reading on both low and high pressure sides. | Overcharged A/C system. | Adjust refrigerant to specified amount. |
| Faulty condenser cooling operation. | Clean condenser. | |||
| Faulty condenser cooling fan operation. | Inspect and repair condenser cooling fan. | |||
| High pressure reading on both low and high pressure sides. Low pressure side tubing is not cold when touched. |
Presence of air in A/C system (Improperly evacuated). | Replace condenser. Inspect quantity of compressor oil and presence of contaminants in oil. Evacuate system and recharge with fresh refrigerant. | ||
| 450 - 550 (4.6 - 5.6) (65.3 - 79.8) | High pressure reading on both low and high pressure sides. Large amount of frost or dew on the low pressure side tubing. | Faulty expansion valve. Refrigerant flow is not regulated properly. |
Replace expansion valve. | |