A/C Compressor Control

A/C Compressor Control is used when accelerating or engine load is instantly increased greatly, in order to improve engine acceleration by temporarily turning off A/C compressor.
A/C Compressor On/Off Control is performed by engine ECU depending on A/C switch signal and blower fan switch input signal. When driver turns on A/C switch and blower fan switch, battery voltage will be delivered through fin thermo switch and triple switch inside low & high switches to engine ECU terminal C13.
Then engine ECU drives A/C compressor relay, to operate A/C compressor. In addition when throttle valve position sensor output voltage rises above 4.1V during A/C compressor control, say during passing or rapid acceleration, ECU will turn off A/C compressor for approx. five seconds for improving running performance of the car. Thereafter A/C compressor will be on again.
A/C compressor control can also perform the below functions:

• A/C compressor off at engine start-up for eight seconds.


• A/C compressor off for protecting engine when coolant temperature is above 115 degree C.
  
• A/C compressor off when idle speed control system is failed.

You can check the actuator actual value and status and activate it when it is possible by AutoHex Auto Diagnostic Scanner under the supported car brand and according to engine type.