Infiniti G37 Coupe. Manual - part 769
MAGNET CLUTCH CONTROL SYSTEM
HAC-65
< FUNCTION DIAGNOSIS >
[AUTOMATIC AIR CONDITIONER]
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HAC
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MAGNET CLUTCH CONTROL SYSTEM
System Diagram
INFOID:0000000001734543
System Description
INFOID:0000000001734544
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 sen-
sor 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 com-
pressor.
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 feed-
back 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/cm
2
, 452 psi) or more, or approximately 118 kPa (1.2 kg/cm
2
, 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 compres-
sor turns ON. The compressor turns OFF when ambient temperature
is lower than
−
5
°
C (23
°
F).
JSIIA0781GB
RHA094GB