Magnet Clutch Control
WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
When A/C switch, AUTO switch or DEF ( ) switch is pressed, A/C auto amp. transmits compressor ON signal to ECM, via CAN communication.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sensor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to IPDM E/R, via CAN communication.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate compressor.
When sending compressor ON signal to IPDM E/R via CAN communication line, ECM simultaneously sends compressor feedback signal to A/C auto amp. via CAN communication line.