Air Conditioning (A/C) Diagnostics - Pressure Zone B. Cadillac DeVille 2002

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2002 🢒 DeVille 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Conditioning (A/C) Diagnostics - Pressure Zone B

Step

Action

Yes

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

Go to Step 2

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

After performing the A/C System Performance Test, did both the high and low side pressures fall within zone B on the A/C Pressure-Zone Classification but after continued operation of the A/C system.

Did the low and high side pressures equalize or become static?

Go to Step 5

Go to Step 3

Refer to the recorded pressures. Inspect for the following conditions:

Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury.

•	The low side pressure equal to or above the specified pressure range of the A/C Performance. Refer to Air Conditioning (A/C) System Performance Test .

•	The high side pressure is below the specified pressure range of the A/C Performance. Refer to Air Conditioning (A/C) System Performance Test .

•	The low side refrigerant line at the compressor feels cool-to-warm.

•	The high side refrigerant line at the compressor feels warm-to-hot.

Do the listed conditions exist?

Go to Step 6

Go to Step 4

Inspect for the following conditions:

•	The low side pressure is above the specified pressure range of the A/C Performance. Refer to Air Conditioning (A/C) System Performance Test .

•	The high side pressure is below the specified pressure range of the A/C Performance. Refer to Air Conditioning (A/C) System Performance Test .

•	The low side refrigerant line at the compressor feels warm.

•	The high side refrigerant line at the compressor feels warm to hot.

Refer to Air Conditioning (A/C) System Performance Test .

Do the listed conditions exist?

Go to Step 5

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

The A/C compressor is malfunctioning. Replace the compressor. Refer to Air Conditioning Compressor Replacement .

Is the repair complete?

Go to Step 7

The A/C system has a low refrigerant charge. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

Go to Step 7

Take readings of the low and high side pressures as well as the IP outlet air temperature after repairs are performed.
Compare the pressures and 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?

Go to Step 8

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 - Automatic