DEFINITION: The low and the high side pressures are both higher than normal.

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

Go to Step 2

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

1. Start the engine.
2. Turn ON the A/C.
3. Inspect for proper cooling fan operation. Refer to Cooling System Description and Operation in Engine Cooling.

Are the cooling fans ON and operating properly?

Go to Step 3

Go to Step 5

Visually inspect for the following conditions:

Do any of these conditions exist?

Go to Step 4

Go to Step 6

Repair the air flow restriction.

Is the action complete?

Go to Step 9

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Repair the fault to the cooling fan operation. Refer to Cooling Fan Inoperative in Engine Cooling.

Is the repair complete?

Go to Step 9

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

Feel the liquid line on both sides of the expansion device.

Are the temperatures on both sides of the expansion device similar?

Go to Step 7

Go to Step 8

Replace the damaged or faulty thermal expansion valve. Refer to Thermal Expansion Valve Replacement .

Is the action complete?

Go to Step 9

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1. Air is in the refrigerant system, or the system is overcharged. Refer to the view screen on J 43600 for foreign gas content in the refrigerant.
2. Recover and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the action complete?

Go to Step 9

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1. Record the low and high side pressures and the IP panel outlet air temperature after you have performed the repairs.
2. Compare the pressures and the panel outlet temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test .

Are the readings within the specified ranges listed in the A/C Performance Chart?

Go to Step 10

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

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Symptoms - HVAC Systems - Manual