PT Cruiser L4-2.4L Turbo (2009)
Compressor Clutch: Description and Operation
A/C Compressor Clutch - Operation
A/C CLUTCH
The A/C clutch components provide the means to engage and disengage the A/C 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 coil is not energized, the pulley freewheels on the clutch hub bearing, which is part of the pulley assembly.
A/C clutch engagement is controlled by the Powertrain Control Module (PCM) or Engine Control Module (ECM), depending on engine application.
When the A/C switch is pressed to the On position, the switch sends a request signal on a dedicated hard-wired circuit to the Cabin Compartment Node
(CCN), which sends a message on the Controller Area Network (CAN) B Bus to the Totally Integrated Power Module (TIPM), which then transfers the
request on the CAN C Bus to the PCM/ECM, which determines if operating conditions are correct for A/C clutch engagement. When all operating
conditions have been met, the PCM/ECM sends a signal on a dedicated hard-wired circuit back to the TIPM to energize the internal A/C clutch high side
driver. When energized, the A/C clutch high side driver provides battery current to the A/C clutch coil. Depending on engine application, a gateway
module is used by the TIPM to communicate to the PCM on the CAN Bus.
The A/C clutch control system is diagnosed using a scan tool . See: Testing and Inspection
The A/C clutch components cannot be adjusted or repaired and must be replaced if inoperative or damaged.