Follow the next table and perform trouble diagnosis if there is a compressor unit malfunction (internal noise, insufficient cooling).

Symptom | Inspection method | Check list | Result | Action
Noise from compressor unit When A/C is ON. (rattling or rolling sound) | Cooker system internal pressure | Check with manifold gauge | Both high‐ and low‐pressure sides are high.*2 | Recharge with proper amount of refrigerant.
High/low‐pressures hunt.*2 | Replace compressor only.
Check compressor oil condition. | Sample compressor oil and judge. | Refer to the criteria shown in compressor lubricant. | Judgment result 1: Replace compressor only. Judgment result 2: Replace compressor and liquid tank.
Insufficient cooling*1 | Compressor body | Check rotation of compressor. If sized or stuck, sample compressor oil and judge.
Cooler system internal pressure | Check with a manifold gauge. Sample compressor oil and judge if the difference between high‐pressure and low‐pressure is small or if they are almost the same.
Outlet air temperature rises temporarily while driving.*2 | — | — | — | Replace compressor only.

*1: First conduct inspection according to trouble diagnosis for each malfunction.
*2: Applicable to variable capacity compressor only.