yes u can control ur compressor through ur car thermostate knob. see owner manual section 1-9 page 157. link is below
vitz 2nd generation owner manual
All ours car equipped with manually control climate unit / air-conditioning unit (to control climate of cabin i-e; heating / cooling / ventilation). Auto/digital control climate unit is a more sophisticated form of air-conditioning, which allows the temperature of a car’s interior to be accurately controlled. Users can set the required temperature and the system automatically adjusts the speed and amount of cold air introduced into the cabin. This is different to air-conditioning, which has its speed and amount of cold air controlled by the driver.
Vitz Auto/Digital Climate Control Unit
EU yaris Auto/digital climate control unit