Were you sent here from the A/C System Performance Test?

Go to Step 2

Go to Air Conditioning (A/C) System Performance Test

Refer to the air outlet temperatures recorded

Is there a 2° - 3° difference in the discharge air temperature between the right and left center I/P outlets?

Go to Step 7

Go to Step 3

Did the customer concern mention that the A/C system output temperatures are good at first, but then turn warm during extended drives?

Go to Step 4

Go to Step 5

Increase engine speed to 2000 RPM.

During extended operation of the A/C system, does the low side pressure decrease (possibly accompanied by heavy frost on the liquid line between the expansion device and the evaporator)?

Go to Air Conditioning (A/C) Diagnostics - Pressure Zone D

Go to Step 5

Refer to the low and high side pressures recorded.

Inspect for the following conditions:

Caution: Refer to Moving Parts and Hot Surfaces Caution in the Preface section.

Do the listed conditions exist?

Go to Step 7

Go to Step 6

Refer to the low and high side pressures recorded.

Inspect for the following conditions:

Do the listed conditions exist?

Go to Step 8

Go to Too Hot in Vehicle in HVAC Systems - Manual or Too Hot in Vehicle in HVAC Systems - Automatic

The A/C system is undercharged, but not enough to show a difference in low or high side pressures.

1. Leak test A/C system. Refer to Leak Testing
2. Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

Go to Step 14

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The A/C system may be contaminated.

Check the J 43600 information screen for detection of foreign gases in A/C system.

Do foreign gases exist?

Go to Step 9

Go to Step 10

1. Evacuate A/C system to a scavenging tank then recharge the system to specifications.

Refer to Refrigerant Recovery and Recharging .

2. Leak test the A/C system. Refer to Leak Testing .

Is the repair complete?

Go to Step 14

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The A/C system may contain too much moisture or air.

1. Evacuate and recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .
2. Leak test the A/C system. Refer to Leak Testing .
3. Operate the A/C system and check the outlet air temperatures.

Are the outlet temperatures within the specified ranges of the A/C Performance Test Table? Refer to Air Conditioning (A/C) System Performance Test .

Go to Step 14

Go to Step 11

The A/C system may contain too much refrigerant oil.

1. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging .
2. Remove the accumulator. Refer to Air Conditioning Accumulator Replacement .
3. Drain the refrigerant oil from the accumulator and measure the amount.

Is there more than 5 oz. of refrigerant oil in the accumulator?

Go to Step 12

Go to Step 13

1. Reinstall the Accumulator. Refer to Air Conditioning Accumulator Replacement .
2. Add the specified amount of refrigerant oil to the A/C system. Refer to Refrigerant System Capacities .
3. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
4. Leak test the A/C system. Refer to Leak Testing .

Are the repairs complete?

Go to Step 14

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1. Add the specified amount of refrigerant oil to the A/C system. Refer to Refrigerant System Capacities .
2. Install the accumulator. Refer to Air Conditioning Accumulator Replacement .
3. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
4. Leak Test the A/C system. Refer to Leak Testing .

Are the repairs complete?

Go to Step 14

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Take readings of the low and high side pressures as well as the IP outlet air temperature.

Compare the outlet temperatures to those listed in the A/C System Performance Chart. Refer to Air Conditioning (A/C) System Performance Test .

Are the high and low side pressures and outlet temperatures within specifications?

Go to Step 15

Go to Air Conditioning (A/C) System Performance Test

Operate the system in order to verify the repair.

Did you correct the condition ?

System OK

Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic