Handling Insufficient Refrigerant Level
If an insufficient refrigerant level is detected at troubleshooting, do not charge (add) the refrigerant. Because an accurate amount of refrigerant cannot be determined from the pressure indicated on the manifold gauge, never charge the refrigerant. If there is too much or too little refrigerant from the refilling, there may be secondary problems such as damage to the refrigerant cycle parts, or a decrease of cooling performance. Therefore, if it is determined that the refrigerant level is insufficient, completely remove refrigerant from the refrigerant cycle and refill with refrigerant to the specified amount.
Handling Compressor Oil
Use only the following specified compressor oil for this vehicle. Using compressor oil (PAG oil) other than specified compressor oil can damage the A/C compressor.
FD46XG
Do not spill compressor oil on the vehicle. A drop of compressor oil on the vehicle surface can eat away at the paint. If oil gets on the vehicle, wipe it off immediately.
Compressor oil (PAG oil) has a higher moisture absorption efficiency than the previously used mineral oil. If moisture mixes with the compressor oil, the refrigerant system could be damaged. Therefore, install caps immediately after using the compressor oil or removing refrigerant system parts to prevent moisture absorption.
If the refrigerant gas is completely discharged from the system for reasons such as a malfunction during A/C operation, repair or replace the malfunctioning part, charge the refrigerant to the specified amount and always add 60 ml {60 cc, 2.0 fl oz} of compressor. If the compressor oil is not adequately replenished, the A/C compressor may quickly deteriorate, abnormal noise may develop, cooling performance may be affected or, in the worst case, the A/C compressor may seize.

Refrigerant Pressure Sensor [Manual Air Conditioner]
Refrigerant System Service WarningsAir Fuel Ratio (A/F) Sensor
Purpose/Function
Detects the oxygen concentration (all-range air/fuel ratio) in the exhaust
gas as basic information for mainly determining the fuel injection amount.
Detects the oxygen concentration (all-range air/fuel ratio) in the exhaust
gas and inputs it to the PCM as an ox ...
DSC Related Parts Sensor Initialization Procedure
WARNING:
If the initialization procedure is not completed, the DSC will not operate
properly and it might cause an unexpected accident. Therefore, after replacing
or removing the DSC HU/CM or SAS control module, make sure to perform the initialization
procedure to insure proper DSC ...
Heater Core Inspection
1. Inspect the heater core for damage, cracks, and water leakage.
If there is any malfunction, replace the heater core.
2. Visually inspect the fins for bending.
If there is any bending, use the end of a flathead screwdriver to straighten
the fins.
3. Visually inspect ...