Compressor Control

SYSTEM


Compressor Control


DESCRIPTION
- BCM transmits the A/C ON signal and blower fan ON signal to ECM via CAN communication line only when the compressor operational condition is satisfied, and A/C indicator is turned ON. Without Intelligent Key System.

NOTE:
Compressor operational condition
- A/C switch signal ON or defroster position signal ON
- Blower fan ON signal: ON
- Thermo control amp. signal: ON
- ECM judges the conditions of each sensor (Refrigerant pressure sensor signal, accelerator position signal, etc.), and transmits the A/C compressor request signal to IPDM E/R via CAN communication line.
- By receiving the A/C compressor request signal from ECM, IPDM E/R turns the A/C relay to ON, and activates the compressor. IPDM E/R (Without I-Key).

CONTROL BY THERMO CONTROL AMP.

Low Temperature Protection Control





- When the thermo control amp. detects that evaporator fin temperature is 2�C (36�F) or less, thermo control amp. signal becomes
OFF, and stops the compressor.
- When the air temperature returns to 3.5�C (38�F) or more, the compressor is activated.

Operating Rate Control
- Thermo control amp. detects the positions of temperature control dial (air mix PBR) and MODE dial (MODE switch).
- Thermo control amp. corrects the stopping temperature of A/C compressor depending on the condition of A/C operation, and prevents too much heating by turning thermo control amp. signal ON - OFF.

CONTROL BY ECM

Compressor Protection Control at Pressure Malfunction
When the high-pressure side value that is detected by refrigerant pressure sensor is as per the following state, ECM requests IPDM E/R to turn A/C relay OFF and stops the compressor.
- 3.12 MPa (31.82 kg/cm2, 452.4 psi) or more (When the engine speed is less than 1,500 rpm)
- 2.74 MPa (27.95 kg/cm2, 397.3 psi) or more (When the engine speed is 1,500 rpm or more)
- 0.14 MPa (1.43 kg/cm2, 20.3 psi) or less

Compressor Oil Circulation Control
When the engine starts while the engine coolant temperature is 56�C (133�F) or less, ECM activates the compressor for approximately 6 seconds and circulates the compressor oil once.

Air Conditioning Cut Control
When the engine condition is high load, ECM transmit A/C relay OFF request to IPDM E/R, and stops the compressor. System Description.