Air fuel ratio control performs fuel injection control based on the oxygen density detected in exhaust gas in order to bring the intake mixture in the vicinity of a target air fuel ratio.
This high-precision air fuel ratio control is realized by detecting a correction value with an air fuel ratio (A/F) sensor (Sensor 1) and then applying further correction with a secondary heated oxygen sensor (secondary HO2S) (Sensor 2).
The powertrain control module (PCM) supplies a current to the A/F sensor (Sensor 1), and monitors the current value which varies with the oxygen density in the measuring chamber of the sensor.
The current value is proportional to the air fuel ratio, therefore the PCM can calculate the air fuel ratio from the value of the current.

The secondary heated oxygen sensor (secondary HO2S) (Sensor 2) detects the oxygen density in the exhaust gas passing through the catalyst and outputs it to the powertrain control module (PCM) to enable the high-precision air fuel ratio control, which cannot be realized only with an A/F sensor (Sensor 1).
A ceramic heater is equipped inside the element in order to shorten sensor reaction time and to enable output that is constantly stable.

Every time one of the three protrusions of the pulse plate attached to the intake camshaft passes over camshaft position (CMP) sensor A, a pulse signal is delivered.

1.5 L engine:
The mass air flow (MAF) sensor/intake air temperature (IAT) sensor has the MAF sensor contains a heater and two temperature sensors that are located on both sides of the heater at a very close distance.
The heater is supplied current to the heating control at a constant temperature. The sensors upstream side and downstream side detect the mass air flow and the direction of air flow from the temperature difference due to heat conduction of air.
The MAF sensor outputs the signal using a frequency (Hz).

2.4 L engine:
The mass air flow (MAF) sensor/intake air temperature (IAT) sensor 1 contains a hot wire sensor, a cold wire sensor, and a thermistor. The sensor is in the intake air passage. The resistance of the hot wire, the cold wire, and the thermistor changes due to intake air temperature and air flow. The control circuit in the MAF sensor controls the current to keep the hot wire at a set temperature. The current is converted to voltage in the control circuit, then sent as an input to the PCM.

The MAP sensor converts manifold absolute pressure into electrical signals to the PCM.

The knock control system adjusts the ignition timing to minimize knock.

ECT sensors 1 and 2 are temperature dependent resistors (thermistors). The resistance decreases as the engine coolant temperature increases.