9-3 Arc/Aero (9440) L4-2.0L Turbo (2.0 T) (2004)
Sensor capacitance between the metal plating of the discs is changed based on the pressure. A circuit integrated in the sensor converts the capacitance to
an analogue voltage.
Based on the pressure in the charge air pipe, the pressure sensor yields a proportional voltage to control module pin 24(B).
The control module measures air temperature in the induction pipe by supplying the sensor 5 V through a 1.50 kOhm resistor integrated in the control
module from pin 10(B). Voltage across the resistor in the control module is proportional to the intake air temperature.
Airmass control determines which airmass/combustion is to be sucked in during the cylinder's intake stroke. The value corresponds to engine torque.
Throttle control sets the throttle so that the actual airmass/combustion matches that which is requested. If air density before the throttle is high, a smaller
throttle angle is required than if the air density is low. Air density is therefore calculated by the control module using boost pressure and intake air
temperature.