Air Conditioning (A/C) Diagnostics - Pressure Zone B. Cadillac Seville 2003

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2003 🢒 Seville 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Conditioning (A/C) Diagnostics - Pressure Zone B

Step

Action

Yes

DEFINITION: The low side pressure is higher than normal and the high side pressure is lower than normal.

•	Malfunctioning A/C Compressor

•	Refrigerant Under Charge

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

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

•	The high side pressure is below the specified pressure range of the A/C Performance Table. 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.

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 I/P 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