Activation and deactivation of the air-conditioning compressor depends on a number of vehicle and control-unit states. When high torque is needed for brief period (pulling away from rest, accelerating) the air-conditioning compressor control logic shuts down the air-conditioning compressor to ensure that sufficient engine torque is available.
Activation comprises two subfunctions:
โข Air-conditioning compressor logic
โข A/C compressor activation
Air-conditioning compressor logic
The logic checks all conditions which prevent activation of the air-conditioning compressor:
โข Pulling away from rest (vehicle speed, accelerator pedal, engine speed)
โข Acceleration (change in accelerator pedal position, vehicle speed, engine speed)
โข Oil temperature
โข Coolant temperature
โข Engine starting procedure
โข System fault (defect in road-speed sensor or accelerator pedal faulty)
โข A dummy value is used if the oil temperature sensor or the coolant temperature sensor is faulty
A/C compressor activation
Activation drives the output as a function of:
โข Air conditioning request via CAN and
โข A/C compressor logic
Idle-speed increase is not implemented.