A/C Compressor Clutch - Operation

CLUTCH - FIXED DISPLACEMENT A/C COMPRESSOR

The A/C clutch components for the Denso fixed displacement A/C compressors provide the means to engage and disengage the compressor from the engine accessory drive belt. When the electromagnetic A/C clutch coil is energized, it magnetically draws the clutch plate into contact with the clutch pulley and drives the compressor shaft. When the A/C clutch coil is not energized, the pulley free-wheels on the clutch hub bearing, which is part of the pulley assembly.

A/C clutch engagement is controlled by the Powertrain Control Module (PCM). When the A/C heater controls are set to any A/C position, the A/C heater module sends a request signal on the Controller Area Network (CAN) data bus to the PCM, which then determines if operating conditions are correct for A/C clutch engagement. When all operating conditions have been met, the PCM energizes a relay in the Power Distribution Center (PDC), which sends battery current to the A/C clutch coil.

The A/C clutch coil and relay are protected by a fuse in the PDC.

The A/C clutch control system is diagnosed using a scan tool Testing and Inspection.

A/C clutch components cannot be repaired and must be replaced if inoperative or damaged.