GM Service Manual Online
For 1990-2009 cars only
Table 1: High Pressure is Abnormally High
Table 2: A/C Component Checks

High Pressure is Abnormally High

Problem

Action

The A/C condenser is clogged or dirty.

Clean the A/C condenser fins.

The cooling fan is not operating properly.

Check system for malfunction.

A/C Component Checks

Problem

Action

The A/C compressor belt is loose or broken.

Adjust or replace the drive belt.

Refer to Engine Mechanical.

The armature friction face is glazed.

Clean or replace the magnetic armature face.

The clearance between the magnetic drive plate and the pulley is incorrect.

Adjust the clearance.

Refer to Compressor Magnetic Clutch .

The A/C compressor is seized.

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

The refrigerant is insufficiently charged or excessively charged.

  1. Discharge the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  3. Recharge the refrigerant.

Refer to Refrigerant Recovery and Recharging .

Leaks are present in the refrigerant system.

Inspect the refrigerant system for leaks.

Refer to Leak Testing .

The A/C condenser is clogged. The radiation in the A/C condenser is not sufficient.

Clean or replace the A/C condenser, as necessary.

Refer to Condenser Replacement .

The A/C expansion valve is operating incorrectly due to a foreign substance.

Replace the A/C expansion valve.

Refer to Thermal Expansion Valve Replacement .