GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Aveo 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 HVAC Preliminary Checks

If you suspect a problem in the refrigerant system, inspect for the following conditions:

  1. Inspect the outer surfaces of the radiator and the condenser cores to be sure that the airflow is not blocked by dirt, leaves, or other foreign material. Inspect between the condenser and the radiator, as well as all outer surfaces.
  2. Inspect for restrictions or kinks in the condenser core, the hoses, and the tubes.
  3. Inspect the operation of the blower fan.
  4. Inspect all the air ducts for leaks or restrictions. A low airflow rate may indicate a restricted evaporator core.
  5. Inspect for slippage of the compressor clutch.
  6. Inspect the tension on the serpentine accessory drive belt.

Insufficient Cooling - Quick Check Procedure

Perform the following hand-feel procedure to get a quick idea of whether the air conditioning (A/C) system has the proper charge of Refrigerant-134a. The air temperature must be above 21°C (70°F) for most models.

  1. Warm up engine. Run the engine at idle.
  2. Open the hood and all the doors.
  3. Turn the A/C switch ON.
  4. Set the temperature control to the full cold position.
  5. Set the blower speed switch on 4.
  6. Hand-feel the temperature of the evaporator outlet pipe. The pipe should be cold.
  7. Inspect for other problems. Refer to HVAC Preliminary Checks .
  8. Leak check the system. Refer to Leak Testing . If you find a leak, discharge the system and repair the leak as required. After completing the repair, evacuate and charge the system.
  9. If there is no leak, refer to Too Hot in Vehicle .

Pressure Temperature Relationship of R-134A

°C

°F

kPa

psi

°C

°F

kPa

psi

*All values rounded to 2 decimal places.

EVAPORATOR RANGE: From -6.67 to +7.22°C (20-45°F), the temperatures represent the gas temperatures inside the coil and not on the coil surfaces. Add 1.67-5.56°C (3-10°F) to the temperature for coil and air-off temperatures.

CONDENSER RANGE: From 43-71°C (110-160°F), temperatures are not ambient. Add 19.4-22.2°C (35-40°F) for proper heat transfer, then refer to the pressure chart.

Example: 32°C (90°F) ambient temperature +22°C (40°F) = 54°C (130°F). Condenser temperature = 1 379 kPa (200 psi), based on 48.3 km/h (30 mph) airflow.

-8.89

16

105.70

15.33

37.78

100

856.84

124.27

-7.78

18

114.87

16.66

38.89

102

886.56

128.58

-6.67

20

124.32

18.03

40

104

916.35

132.98

-5.56

22

134.11

19.45

41.11

106

947.92

137.48

-4.44

24

144.24

20.92

42.22

108

979.64

142.08

-3.33

26

154.65

22.43

43.33

110

1012.11

146.79

-2.22

28

165.48

24

44.44

112

1045.21

151.59

-1.11

30

176.65

25.62

45.56

114

1079.14

156.51

0

32

188.16

27.29

46.67

116

1113.75

161.53

1.11

34

200.02

29.01

47.78

118

1149.12

166.66

2.22

36

212.30

30.79

48.89

120

1185.18

171.89

3.33

38

224.98

32.63

50

122

1222.07

177.24

4.44

40

238.08

34.53

51.11

124

1259.72

182.70

7.22

45

272.49

39.52

52.22

126

1298.12

188.27

10

50

309.58

44.9

53.33

128

1337.35

193.96

12.77

55

349.51

50.69

54.44

130

1377.35

199.76

15.56

60

392.33

56.9

57.22

135

1480.91

214.78

18.33

65

438.18

63.55

60

140

1589.57

230.54

21.11

70

487.27

70.67

62.78

145

1703.62

247.08

23.89

75

539.67

78.27

65.56

150

1823.04

264.4

26.67

80

609.38

88.38

68.33

155

1948.04

272.53

29.44

85

655.09

95.01

71.11

160

2078.77

301.49

32.22

90

718.39

104.19

73.89

165

2215.29

321.29

35

95

785.61

113.94

76.67

170

2357.81

341.96