Air Conditioning: Notes

The A/C system components are the following:

• A/C compressor
• A/C condenser core
• A/C evaporator core
• Receiver/drier cartridge
• Connecting refrigerant lines
• Thermostatic Expansion Valve (TXV)
• Evaporator temperature sensor
• A/C pressure transducer
• A/C compressor pressure relief valve

The refrigerant system incorporates an A/C compressor controlled by the PCM through an A/C clutch relay.

The A/C compressor clutch will only be engaged by the PCM if all of the following conditions are met:

• The HVAC module is set to a mode which provides an A/C request to the PCM.
• The evaporator temperature sensor is reading a temperature above 3°C (37°F).
• The A/C pressure transducer is not reading an excessively high or excessively low pressure in the refrigerant system.
• The A/C compressor relay is switched to the CLOSED position by the PCM.
• The Engine Coolant Temperature (ECT) is not excessively high.
• The PCM has not detected a Wide Open Throttle (WOT) condition.

Refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS for operating specifications.

An A/C compressor pressure relief valve is installed in the A/C compressor to protect the refrigerant system against excessively high refrigerant pressure.

Refrigerant flow into the evaporator core is metered by a TXV  .