Magnet Clutch Control System
MAGNET CLUTCH CONTROL SYSTEMSystem Diagram
System Description
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature and signal from ECM.
SYSTEM OPERATION
When A/C switch, AUTO switch, DEF switch or D/F switch is pressed, unified meter and A/C 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 ECM via CAN communication line.
ECM sends compressor feedback signal to unified meter and A/C amp., then, uses input compressor feedback signal to control air inlet.
Compressor Protection Control
When the high-pressure side detected by the refrigerant pressure sensor is either approximately 3,119 kPa (31.8 kg/sq.cm, 452 psi) or more, or approximately 118 kPa (1.2 kg/sq.cm, 17 psi) or less, ECM turns the A/C relay OFF and stops the compressor.
Low Temperature Protection Control
Unified meter and A/C amp. turns compressor ON or OFF as judged by a signal detected by ambient sensor and intake sensor.
When ambient temperature is higher than -2 °C (28 °F), the compressor turns ON. The compressor turns OFF when ambient temperature is lower than -5 °C (23 °F).
When intake air temperature is higher than 1 °C (34 °F), the compressor turns ON. The compressor turns OFF when intake air temperature is lower than -5 °C (23 °F).