A/C Compressor Clutch Controls

NOTE: For specific A/C clutch circuit testing, see A/C CLUTCH CIRCUIT DIAGNOSIS test.

To provide improved idle quality, improved Wide Open Throttle (WOT) performance and A/C system protection, the A/C compressor clutch is controlled by the PCM.

For proper control of cooling fans, A/C compressor clutch and Idle Air Control (IAC) valve, a refrigerant pressure sensor is used. PCM uses signal provided by sensor to monitor high and low side refrigerant pressures. If PCM detects a fault in refrigerant pressure circuit, A/C compressor clutch will be disabled.

The A/C compressor clutch relay is controlled by PCM. This allows PCM to raise idle speed before engaging compressor clutch, or disable compressor clutch during WOT, high engine RPM, high power steering loads and hot engine restarts. PCM also disables compressor clutch if coolant temperature becomes excessive.

NOTE: See appropriate diagram in WIRING DIAGRAMS article for terminal and wire color ID. For component location, see COMPONENT LOCATION

A/C COMPRESSOR CLUTCH RELAY LOCATION

Application	Location
"Y" Body	In Underhood Electrical Center, Above Battery

WARNING: Vehicles may be equipped with a PCM using an Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing PCM, the new PCM must be programmed.

NOTE: To help save diagnostic time, ALWAYS check for blown fuses or fusible links before proceeding with any testing. If fuses are blown, locate and repair short circuit before replacing fuses. Ensure all related relay and wire harness connections are clean and tight. Repair as necessary.