For 1990-2009 cars

Table 1: | System Performance Table

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: The performance test measures the air conditioning system operating efficiency. The test measures and compares the following areas:

• | The pressures at the high-pressure and low-pressure sides of the refrigeration system

• | The temperature of the air being discharged into the passenger compartment

• | The evaporator temperature

1 | Perform a functional check in order to ensure that the air distribution system valves are functioning properly. When functioning properly the valves route all of the air that passes through the evaporator to the outlets. Refer to Functional Check .

Are the valves functioning properly?

--

Go to Step 2

--

2 |

1. Rotate the temperature knob from full COLD to full HOT and back to full COLD.
2. Listen for the temperature valve to seat in both the full HOT and full COLD position. A thud noise indicates that the valve is seated.

Does the temperature valve seat in both positions?

--

Go to Step 3

Go to Step 9

3 |

1. Park the vehicle indoors.
2. Close the doors and the windows.
3. Select the full COLD, MAX A/C mode.
4. Select the HIGH blower motor speed.
5. Place the vehicle in park (automatic transmission).
6. Set the parking brake (manual or automatic transmission).
7. Start the engine.

Does the compressor engage?

--

Go to Step 4

Go to Step 5

4 |

1. Install the scan tool with the powertrain cartridge.
2. Select the field service mode.
3. Use the scan tool to energize the cooling fans.
4. Inspect the cooling fan operation.

Are both cooling fans operating?

--

Go to Step 7

Go to Step 6

5 | Refer to Engine Controls for A/C Compressor Diagnosis. | -- | -- | --
6 | Repair the cooling fan circuit. Refer to Engine Controls. Is the repair complete? | -- | System OK | --
7 |

1. Install the J 39183-C or the J 39500-B onto the vehicle.
2. Install the J 6742-03 or the equivalent into the center instrument panel outlet.
3. Run the vehicle at the following settings:

• | MAX A/C mode

• | Full COLD

• | HIGH blower speed

4. Continue to run the vehicle at these settings for 2 minutes . Record the following information:

• | The A/C system high and low side pressure

• | The ambient temperature and humidity

5. Compare these measurements with the air conditioning performance chart. Refer to the performance chart which follows this test.

Is the vehicle A/C performance within specifications?

--

System OK

Go to Step 8

8 | Refer to the VDOT A/C system diagnostic charts within this section. | -- | -- | --
9 |

1. Disconnect the temperature cable at the heater and evaporator module.
2. Rotate the temperature lever from full HOT to full COLD while watching the cable end.

Does the cable end rotate when the temperature lever is rotated?

--

Go to Step 11

Go to Step 10

10 | Repair or replace the temperature cable as necessary. Is the repair complete? | -- | System OK | --
11 | Manually rotate the temperature valve by hand. Does the temperature valve rotate easily to both the full HOT and full COLD position with approximately 50 degrees of travel? | -- | Go to Step 12 | Go to Step 13
12 | Adjust or replace the temperature cable. Is the repair complete? | -- | System OK | --
13 | Repair or replace the heater and evaporator module. Is the repair complete? | -- | System OK | --

#### System Performance Table

Temperature | Humidity | Low Gauge Pressure | High Gauge Pressure | Center Outlet Temperature
--- | --- | --- | --- | ---
21°-27°C (70°- 80°F) | Less than 50% | 165-234 kPa (24- 34 psi) | 793-1310 kPa (115-190 psi) | 3°-9-C (38°-34°F)
More than 50% | 172-255 kPa (25- 37 psi) | 793-1379 kPa (115-200 psi) | 4°-13°C (40°- 55°F)
27°-33°C (80°- 90°F) | Less than 50% | 193-262 kPa (28- 38 psi) | 965-1482 kPa (140-215 psi) | 3°-13°C (38°- 55°F)
More than 50% | 207-276 kPa (30- 40 psi) | 1034-1620 kPa (150-235 psi) | 7°-18°C (45°- 65°F)
33°-38°C (90°- 100°F) | Less than 40% | 234-296 kPa (34- 43 psi) | 1138-1793 kPa (165-260 psi) | 7°-17°C (45°- 63°F)
More than 40% | 251-331 kPa (36- 48 psi) | 1276-1862 kPa (185-270 psi) | 13°-20°C (55°- 68°F)
38°-44°C (100°- 110°F) | Less than 20% | 276-338 kPa (40- 49 psi) | 1448-2000 kPa (210-290 psi) | 12°-18°C (53°- 64°F)
More than 20% | 296-359 kPa (43- 52 psi) | 1517-2137 kPa (220-310 psi) | 14°-21°C (58°- 70°F)