Compressor Control

AUTOMATIC AIR CONDITIONING SYSTEM (WITH FOREST AIR) : Compressor Control


DESCRIPTION
- When the compressor activation condition is satisfied while blower motor is activated, A/C auto amp. transmits A/C ON signal and blower fan ON signal to ECM via CAN communication.
- ECM judges that the compressor can be activated depending on each sensors state (refrigerant pressure sensor signal, throttle position sensor signal, and others). And transmits air conditioner relay control signal to IPDM E/R via CAN communication.
- IPDM E/R turns air conditioner relay ON and activates the compressor depending on request from ECM.

COMPRESSOR PROTECTION CONTROL AT PRESSURE MALFUNCTION
When high-pressure side value that is detected by refrigerant pressure sensor is as per the following state, ECM requests IPDM E/R to turn air conditioner relay OFF and stops the compressor.
- 3.12 MPa (31.20 bar, 31.8 kg/cm2, 452 psi) or more (When the engine speed is less than 1,500 rpm)
- 2.74 MPa (27.40 bar, 27.9 kg/cm2, 397 psi) or more (When the engine speed is 1,500 rpm or more)
- 0.12 MPa (1.20 bar, 1.2 kg/cm2, 17 psi) or less

LOW TEMPERATURE PROTECTION CONTROL
- When intake sensor detects that evaporator fin temperature is -5�C (23�F) or less, A/C auto amp. requests ECM to turn compressor OFF, and stops the compressor.





- When the evaporator fin temperature returns to 1�C (34�F) or more, the compressor is activated.

OPERATING RATE CONTROL
When set temperature is other than fully cold or air outlet is "VENT", "B/L" or "FOOT" A/C auto amp. controls the compressor activation depending on ambient temperature.

AIR CONDITIONING CUT CONTROL
When the engine is running in excessively high load condition, ECM requests IPDM E/R to turn air conditioner relay OFF, and stops the compressor. System Description (VQ37VHR) or System Description (VK56VD) for details.