Heating and Air Conditioning: Service Precautions
A/C System CautionCAUTION:
The air conditioning system of this vehicle uses refrigerant HFC-134a (R-134a).
None of refrigerant, compressor oil and component parts is interchangeable between two types of A/C: one using refrigerant CFC-12 (R-12) and the other using refrigerant HFC-134a (R-134a).
Be sure to check which refrigerant is used before any service work including inspection and maintenance. For identification between these two types, refer to A/C Refrigerant Type Description.
When replenishing or changing refrigerant and compressor oil and when replacing parts, make sure that the material or the part to be used is appropriate to the A/C installed in the vehicle being serviced. Use of incorrect one will result in leakage of refrigerant, damage in parts or other faulty condition.
Precautions on Servicing A/C System
WARNING:
Should refrigerant HFC-134a (R-134a) strike your eye(s), consult a doctor immediately.
- DO NOT USE YOUR HAND TO RUB AFFECTED EYE(S).
Instead, use quantities of fresh cold water to splash it over affected area to thus gradually raise its temperature above the freezing point.
- Obtain proper treatment as soon as possible from a doctor or eye specialist.
Should liquid refrigerant HFC-134a (R-134a) get on your skin, such affected part should be treated in the same manner as when skin is frostbitten or frozen.
CAUTION: None of refrigerant, compressor oil and component parts is interchangeable between two types of A/C: one using CFC-12 (R-12) and the other using HFC-134a (R-134a).
For identification between these 2 types, refer to A/C Refrigerant Type Description.
When replenishing or changing refrigerant and compressor oil and when replacing parts, make sure that the material or the part to be used is appropriate to the A/C installed in the vehicle being serviced.
Use of incorrect one will result in leakage of refrigerant, damage in parts or other faulty condition.
When servicing air conditioning system, the following rules must be observed.
Piping
For H25 Engine Model:
For H27 Engine Model:
- When connecting hoses and pipes, apply a few drops of compressor oil (refrigerant oil) to seats of coupling nuts and O-ring.
- Never use heat for bending pipes. When bending a pipe, try to make its bending radius as slight as possible.
- Keep internal parts of air conditioning free from moisture and dirt. When disconnecting any line from system, install a blind plug or cap to the fitting immediately.
- When tightening or loosening a fitting, use two wrenches, one for turning and the other for support.
- Tighten flared nuts to specified torque.
Tightening torque
8 mm (0.31 in.) pipe 15 N.m (1.5 kg.m, 11.0 lb.ft)
16 mm (0.63 in.) pipe 25 N.m (2.5 kg.m, 18.0 lb.ft)
- Route drain hose so that drained water does not make any contact to vehicle components.
Handling Refrigerant HFC-134a (R-134a)
- When handling refrigerant, always wear goggles to protect your eyes.
- Avoid you direct contact to liquid refrigerant.
- Do not heat refrigerant container higher than 40 °C (104 °F).
- Do not discharge refrigerant into atmosphere.
- Do not allow liquid refrigerant to touch bright metals. Refrigerant combined with moisture is corrosive and will tarnish surfaces of bright metals including chrome.
- After recovering refrigerant from system, the amount of compressor oil removed must be measured and the same amount added to the system.
Refrigerant Recovery
When discharging refrigerant out of A/C system, always recover it by using refrigerant recovery and recycling equipment. Discharging refrigerant HFC-134a (R-134a) into atmosphere would cause adverse effect to environments.
NOTE: When handling recovery and recycling equipment, be sure to follow the instruction manual for the equipment.
Refrigerant Charge
Charge a proper amount of refrigerant to A/C system according to charging procedure described in recovery, evacuation and charging.
: Refrigerant 95794-50G00
CAUTION: Do not perform an additional refrigerant charging to A/C system. This cause it to overcharge.
Replenishing Compressor Oil
CAUTION: Be sure to use HFC-134a (R-134a) compressor oil.
When replacing air conditioning parts with new ones, it is necessary to replenish oil by the amount supposedly remaining in each part.
When changing gas only
When it is unavoidable to change gas without replacing any component part for engine removal and installation or for some other reason, replenish 20 cu.cm (20 cc) oil. When replenishing gas only, oil replenishment is not necessary.
When replacing compressor
Compressor oil is sealed in each new compressor (1) by the amount required for air conditioner cycle. Therefore, when using a new compressor for replacement, drain oil from it by the amount calculated as follows.
"C" = "A" - "B"
"C": Amount of oil to be drained
"A": Amount of oil sealed in a new compressor
"B": Amount of oil remaining in removed compressor
NOTE: Compressor assembly supplied from factory is filled up with the following amount of oil.
: Oil 99000-27080 (H25 engine model)
: Oil 99000-99022-00E (H27 engine model)
Amount of oil in new compressor
H25 engine model: 100 cu.cm (100 cc)
H27 engine model with dual A/C: 200 cu.cm (200 cc)
H27 engine model with single A/C: 150 cu.cm (150 cc)
Amount of compressor oil to be replenished after part replacement
Evaporator: 50 cu.cm (50 cc)
Rear evaporator for H27 engine model with dual A/C: 50 cu.cm (50 cc)
Condenser for H25 engine model: 15 cu.cm (15 cc)
Condenser for H27 engine model: 30 cu.cm (30 cc)
Receiver/dryer for H25 engine model: 20 cu.cm (20 cc)
Receiver/dryer for H27 engine model: 10 cu.cm (10 cc)
Hoses: 10 cu.cm (10 cc)
Pipes: 10 cu.cm (10 cc)
Precautions on Servicing Compressor Assembly
CAUTION:
None of refrigerant, compressor oil and component parts is interchangeable between two types of A/C: one using CFC-12 (R-12) and the other using HFC-134a (R-134a).
For identification between these two types, refer to A/C Refrigerant Type Description.
When replenishing or changing refrigerant and compressor oil and when replacing parts, make sure that the material or the part to be used is appropriate to the A/C installed in the vehicle being serviced. Use of incorrect refrigerant or compressor oil will result in leakage of refrigerant, damage in parts or other faulty condition.
When servicing the compressor, keep dirt or foreign material away from getting on or into the compressor parts and system. Clean tools and a clean work area are important for proper service.
The compressor connection and the outside of the compressor should be cleaned before any On-vehicle repair or before removal of the compressor. The parts must be kept clean at all times and any parts to be reassembled should be cleaned with trichloromethane, naphtha, kerosene or equivalent solvent and dried with dry air.
Use only lint free cloths to wipe parts.
The operations described are based on bench overhaul with compressor removed from the vehicle, except as noted. They have been prepared in order of accessibility of the components.
When compressor is removed from the vehicle for servicing, the oil remaining in the compressor should be discarded and new refrigerant oil added to the compressor.
Minor repair procedures may be done on the vehicle without discharging the system. Major repair procedures require that the system be discharged of refrigerant.
Precautions in Diagnosing Trouble
- Do not disconnect connector from HVAC control module, battery cable from battery, or main fuse before reading diagnostic information stored in HVAC control module memory.
- When diagnosing vehicle with automatic air conditioning system indoors, sunload sensor has to be lighted over vertically with an incandescent lamp. Otherwise, DTC B1504 (No.4) is detected even if sunload sensor is normal.
- Each DTC has priority. Only DTC having the highest priority is indicated. Therefore, after troubleshooting the malfunction, diagnosis should be performed again to see if any other DTC(s) having the lower priority is detected. Refer to DTC Table to see the order of priority.
- Both the A/C indicator lamp and the REC (recirculation) indicator lamp have to be pushed simultaneously to read history DTC. If the A/C indicator lamp and the REC (recirculation) indicator lamp are pushed again simultaneously, current DTC can be read.
- During indication of DTC, rear window defogger switch is OFF. However, rear window defogger switch is ON during indication of history DTC.
- After troubleshooting some trouble, DTC can be stored in HVAC control module memory as history DTC.