Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone A. Chevrolet Lumina 2000

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Lumina 🢒 Engine 🢒 Engine Controls - 3.1L (LG8) 🢒 Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone A

Step

Action

Value(s)

Yes

Were you sent here from the Cooling Insufficient, A/C System diagnostic table?

Go to Step 2

Go to Cooling Insufficient - Air Conditioning (A/C) System

Refer to the recorded IP air outlet temperatures.

Is there a difference in discharge temperature between the left and right center IP outlets?

Go to Step 9

Go to Step 3

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

Go to Step 4

Go to Step 5

Start the engine and elevate the engine RPM to 2000 and maintain.

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 orifice and the evaporator)?

Go to Cooling Insufficient - Air Conditioning (A/C) System - Pressure Zone D

Go to Step 5

Refer to the low and high side pressures recorded.

Inspect for the following conditions:

•	The high side pressure slightly above the specified pressure ranges but still within zone A on the A/C System Pressure - Zone Classification .

•	The discharge line is hot

•	The suction line is cool

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:

•	The low side pressure slightly lower than the specified ranges but still within the zone A on the A/C System Pressure - Zone Classification .

•	The discharge line is warm to hot

•	The suction line is cool to warm

Do the listed conditions exist?

Go to Step 8

Go to Symptoms in HVAC Systems - Manual

The A/C system has contamination in it.
Evacuate the A/C system. Refer to Refrigerant Recovery and Recharging .
Check the amount of refrigerant oil removed from the system.
Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .
Leak test the A/C system. Refer to Leak Testing .

Are the operations completed?

Go to Step 10

The A/C system may contain too much moisture.
Evacuate the A/C system. Refer to Refrigerant Recovery and Recharging .

Important: Pay attention to the sight glass on the ACR4 looking for indication of moisture contamination.

If moisture is indicated by the ACR4, replace the accumulator. Refer to Air Conditioning Accumulator Replacement .
Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .
Leak test the A/C system. Refer to Leak Testing

Are the operations completed?

Go to Step 10

The A/C system is under charged but not enough to show a difference in the low and high side pressures.

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

Is the repair complete?

Go to Step 10

Take readings of the low and high side pressures as well as the IP outlet air temperature.
Compare the readings to those listed in the A/C System Performance Table. Refer to Cooling Insufficient - Air Conditioning (A/C) System .

Are the low and high side pressures and outlet air temperature within specifications?

Go to Step 11

Go to Cooling Insufficient - Air Conditioning (A/C) System

Operate the system in order to verify the repair.

Did you correct the condition ?

Go to Step 12

Go to Symptoms in HVAC Systems -Manual

Disconnect the J 39500-B .
Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.

Is the action complete?

System OK