Air Conditioning System: Overview Hyundai Veloster I

Scheme 1

1. R-134a liquid refrigerant is highly volatile. A drop on the skin of your hand could result in localized frostbite. When handling the refrigerant, be sure to wear gloves.
2. It is standard practice to wear goggles or glasses to protect your eyes, and gloves to protect your hands. If the refrigerant splashes into your eyes, wash them with clean water immediately.
3. The R-134a container is highly pressurized. Never leave it in a hot place, and check storage temperature is below 52°C (126°F).
4. An electronic leak detector should be used to check the system for refrigerant leakage. Bear in mind that the R-134a, upon coming into contact with flame, produces phosgene, a highly toxic gas.
5. Use only recommended lubricant for R-134a systems. If lubricants other than the recommended one used, system failure may occur.
6. PAG lubricant absorbs moisture from the atmosphere at a rapid rate, therefore the following precautions must be observed: When removing refrigerant components from a vehicle, cap the components immediately to prevent entry of moisture. When installing refrigerant components to a vehicle, do not remove the cap until just before connecting the components. Complete the connection of all refrigerant tubes and hoses without delay to prevent the A/C system from taking on moisture. Use the recommended lubricant from a sealed container only.
7. If an accidental discharge in the system occurs, ventilate the work area before resume of service.

Scheme 2

1. Never open or loosen a connection before discharging the system.
2. Seal the open fittings of components with a cap or plug immediately to prevent intrusion of moisture or dust.
3. Do not remove the sealing caps from a Replacement component until it is ready to be installed.
4. Before connecting an open fitting, always install a new sealing ring. Coat the fitting and seal with refrigerant oil before making the connection.

Oil Return Operation

There is close affinity between the oil and the refrigerant.

During normal operation, part of the oil recirculation with the refrigerant in the system. When checking the amount of oil in the system, or replacing any component of the system, the compressor must be run in advance for oil return operation. The procedure is as follows

1. Open all the doors and the engine hood.
2. Start the engine and air conditioning switch to "ON" and set the blower motor control knob at its highest position.
3. Run the compressor for more than 20 minutes between 800 and 1, 000 RPM in order to operate the system.
4. Stop the engine.

Description

A/C pressure transducer convert the pressure value of high pressure line into voltage value after measure it. By converted voltage value, engine ECU controls cooling fan by operating it high speed or low speed. Engine ECU stop the operation of compressor when the temperature of refrigerant line is so high or so low irregularly to optimize air conditioning system.

Scheme 3

1. Measure the pressure of high pressure line by measuring voltage output between NO. 1 and NO. 2 terminals.
2. Inspect the voltage value whether it is sufficient to be regular value or not. Voltage = 0.00878835 * Pressure + 0.5
3. If the measured voltage value is not specification, replace the A/C pressure transducer.

Scheme 4

1. Disconnect the negative (-) battery terminal.
2. Recover the refrigerant with a recovery/charging station.
3. Remove the A/C pressure transducer (B) after disconnecting the connector (A). Tightening torque: 10~12 N.m (1.02~1.22 kgf.m, 7.4~8.8 lb-ft) CAUTION: Take care that liquid & suction pipe are not bent.
4. Installation is the reverse order of removal.

The evaporator temperature sensor will detect the evaporator core temperature and interrupt compressor relay power in order to prevent evaporator freezing by excessive cooling

Scheme 5

1. Ignition "OFF".
2. Remove the evaporator temperature sensor after disconnecting the connector.
3. Using the multi-tester, measure resistance between terminal "+" and "-" of evaporator temperature sensor. VOLTAGE SPECIFICATION Evaporator core temperature [°C (°F)] Resistance [kohms] Voltage [V] -20 (-4) 13.59 2.88 -10 (14) 6.273 1.927 0 (32) 3.129 1.192 10 (50) 1.668 0.715 20 (68) 0.942 0.431 30 (86) 0.56 0.265 40 (104) 0.347 0.168 50 (122) 0.224 0.11

Scheme 6

1. Disconnect the negative (-) battery terminal.
2. Disconnect the evaporator temperature sensor connector.
3. Remove the evaporator temperature sensor (A), by pulling it after rotating 90° in a counterclockwise direction.
4. Installation is the reverse order of removal.

1. The ambient temperature sensor is located at the front of the condenser and detects ambient air temperature. It is a negative type thermistor; resistance will increase with lower temperature, and decrease with higher temperatures.
2. The sensor output will be displayed on the AVN.

Scheme 7

1. Ignition "OFF"
2. Disconnect ambient temperature sensor.
3. Check the resistance of ambient temperature sensor between terminal "+" and "-" whether it is changed by changing of the ambient temperature. AMBIENT TEMPERATURE SPECIFICATION Ambient temperature [°C (°F)] Resistance [kohms] -30(-22) 507± 3% -20(-4) 284.5 ± 3% -10(14) 164.2 ± 3% 0 (32) 97.5 ± 3% 10 (50) 59.6 ± 3% 20 (68) 37.46 ± 3% 30(86) 24.18 ± 3% 40(104) 16 ± 3% 50(122) 10.83 ± 3%
4. If the measured resistance is not specification, substitute with a known-good ambient temperature sensor and check for proper operation.
5. If the problem is corrected, replace the ambient temperature sensor.

Scheme 8

Scheme 9

1. Disconnect the negative (-) battery terminal.
2. Remove the engine room under cover (A).
3. Disconnect the connector and then remove the ambient temperature sensor (A).
4. Installation is the reverse order of removal.