For 1990-2009 cars

Table 1: | A/C Performance Table

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. This step determines if there is enough refrigerant in the A/C system to operate it without damage.

2. This step is to determine if the A/C compressor is operating.

3. This step measures the performance of the A/C system.

4. This step is to allow for vehicle variations as well as high ambient temperatures.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: The following test measures the A/C system operating efficiency by comparing:

• | The ambient air temperature

• | The ambient air humidity

• | The pressure at the high-pressure side of the refrigeration system

• | The pressure at the low-pressure side of the refrigeration system

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

1 |

1. Park the vehicle inside or in the shade.
2. Open the windows in order to ventilate the interior of the vehicle.
3. If the engine is at operating temperature, allow the engine to cool.
4. Ensure that the ignition key is in the OFF position.
5. Install the J 39500-B .
6. Record readings of the low and high side STATIC pressures.

The low and high side pressure readings should be almost equal to each other once the system has come to rest.

Are both the low and high side pressures above the specified value ?

345 kPa (50 psi)

Go to Step 2

Go to Leak Testing

2 |

1. Start the vehicle.
2. Turn the A/C on.
3. Visually inspect under the hood to see if the A/C compressor clutch is engaged

Does the compressor clutch engage ?

--

Go to Step 3

Go to HVAC Compressor Clutch Does Not Disengage

3 |

1. Turn the engine OFF.

Important: Record the relative humidity and the ambient temperature AT THE TIME OF THE TEST.

2. Record the ambient temperature at the vehicle.
3. Record the relative humidity, using one of the following methods:

• | Use a psychrometer

• | Consult the local weather bureau

4. Close the vehicle doors and windows.
5. Open the driver's door window 5-6 inches.
6. Set the HVAC control assembly to the following positions:

• | The A/C on

• | The blower control to the highest position

• | The HVAC control assembly to discharge air through the I/P outlets

• | The temperature control to the coldest position

7. Install a thermometer in the I/P left center air outlet.
8. Install a thermometer in the I/P right center air outlet.
9. Apply the parking brake.
10. Place the transaxle/transmission in one of the following positions:

• | PARK

• | NEUTRAL

11. Start the engine and elevate the engine RPM to 2000 and maintain.
12. Operate the A/C system for 5 minutes.
13. Record the following information:

• | The outlet air temperature

• | The low-side pressure

• | The high-side pressure

14. Compare the low and high side pressures and the output temperature to the table below (LINK).

Does all the data recorded fall within the specified ranges of the table below?

--

Go to Step 9

Go to Step 4

4 | If the pressures and temperatures recorded do not fall within the specified ranges:

1. Continue to operate the A/C system for an additional 5 minutes.
2. Record the pressures and temperatures again.
3. Compare the low and high side pressures and the output temperature to the table below.

Does all the data recorded fall within the specified ranges of the table below?

--

Go to Step 9

Go to Step 5

5 | Compare the recorded pressures to the A/C System Pressure - Zone Classification Chart below. Do both the low and high side pressures fall within Zone A on the chart ? | -- | Go to Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone A | Go to Step 6
6 | Do the pressures fall within Zone B ? | -- | Go to Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone B | Go to Step 7
7 | Do the pressures fall within Zone C ? | -- | Go to Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone C | Go to Step 8
8 | Do the pressures fall within Zone D ? | -- | Go to Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone D | Go to Step 9
9 | Operate the system in order to verify the repair. Did you correct the condition ? | -- | System OK | Go to Symptoms in HVAC System - Manual

#### A/C System Pressure -- Zone Classification

#### A/C Performance Table

Relative Humidity | Ambient Air Temperature | Low Side Pressure | Engine Speed | High Side Pressure | Center Air Outlet Temperature
--- | --- | --- | --- | --- | ---
Front | Rear
°C | °F | kPa | psi | kPa | psi | °C | °F | °C | °F
Important: Use this table in conjunction with the appropriate diagnostic tables.
20% | 27 | 80 | 186-228¹ | 27-33¹ | 2000 RPM | 1496-1538¹ | 217-223¹ | 10¹ | 50¹ | 11¹ | 51¹
32 | 90 | 200-241 | 29-35 | 1703-1744 | 247-253 | 12 | 53 | 12 | 53
38 | 100 | 241-283 | 35-41 | 2186-2227 | 317-323 | 14 | 58 | 16 | 60
30% | 20 | 70 | 186-228¹ | 27-33¹ | 2000 RPM | 1496-1538¹ | 217-223¹ | 10¹ | 50¹ | 11¹ | 51¹
27 | 80 | 221-262 | 32-38 | 1772-1813 | 257-263 | 13 | 56 | 13 | 56
32 | 90 | 241-238 | 35-41 | 2144-2186 | 311-317 | 15 | 59 | 16 | 60
38 | 100 | 290-331 | 42-48 | 2496-2537 | 362-368 | 18 | 64 | 18 | 64
40% | 21 | 70 | 186-228¹ | 27-33¹ | 2000 RPM | 1496-1538¹ | 217-223¹ | 11¹ | 51¹ | 11 | 51
27 | 80 | 248-290¹ | 36-42¹ | 2048-2089¹ | 297-303¹ | 15¹ | 59¹ | 15 | 59
32 | 90 | 276-317 | 40-46 | 2427-2468 | 352-358 | 18 | 65 | 18 | 65
38 | 100 | 338-379 | 49-55 | 2668-2710 | 387-393 | 22 | 72 | 22 | 72
50% | 21 | 70 | 207-248¹ | 30-36¹ | 2000 RPM | 1807-1848¹ | 262-268¹ | 13¹ | 55¹ | 13 | 55
27 | 80 | 269-310 | 39-45 | 2193-2234 | 318-324 | 17 | 63 | 17 | 63
32 | 90 | 290-331 | 42-48 | 2462-2503 | 357-363 | 21 | 70 | 21 | 70
38 | 100 | 352-393 | 51-57 | 2703-2744 | 392-398 | 24 | 76 | 24 | 76
60% | 21 | 70 | 221-262¹ | 32-38¹ | 2000 RPM | 1875-1917¹ | 272-278¹ | 13¹ | 55¹ | 13 | 55
27 | 80 | 269-310¹ | 39-45¹ | 2220-2262¹ | 322-328¹ | 16¹ | 60¹ | 16 | 60
32 | 90 | 297-338 | 43-49 | 2462-2503 | 357-363 | 18 | 64 | 18 | 64
38 | 100 | 359-400 | 52-58 | 2703-2744 | 392-398 | 22 | 71 | 23 | 73
70% | 21 | 70 | 228-269¹ | 33-39¹ | 2000 RPM | 1910-1951¹ | 277-283¹ | 11¹ | 51¹ | 11 | 51
27 | 80 | 276-317¹ | 40-46¹ | 2324-2365¹ | 337-343¹ | 14¹ | 58¹ | 15 | 59
32 | 90 | 310-352 | 45-51 | 2462-2503 | 357-363 | 18 | 65 | 19 | 67
38 | 100 | 359-400 | 52-58 | 2737-2779 | 397-403 | 23 | 74 | 23 | 74
80% | 21 | 70 | 290-331¹ | 42-48¹ | 2000 RPM | 1944-1986¹ | 282-288¹ | 10¹ | 50¹ | 11 | 51
27 | 80 | 310-352 | 45-51 | 2358-2400 | 342-348 | 13 | 56 | 14 | 58
32 | 90 | 338 | 49 | 2462-2503 | 357-363 | 19 | 67 | 21 | 69
90% | 21 | 70 | 241-283¹ | 35-41¹ | 2000 RPM | 1979-2020¹ | 287-293¹ | 15¹ | 59¹ | 16 | 60
27 | 80 | 317-359 | 46-52 | 2393-2434 | 347-353 | 16 | 61 | 17 | 62
¹This data reflects the performance obtained while the engine cooling fans were operating in series (low speed), rather than in parallel (high speed).