PGM-FI System Description - Components
Air Fuel Ratio (A/F) Sensor (Sensor 1)
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.
Secondary HO2S (Sensor 2)
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 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.
CKP Sensor
Regularly continuous teeth except for the one position on the CKP pulse plate passes over the CKP sensor, a pulse signal is sent to the PCM.
CMP Sensor A
Every time one of the three protrusions of the pulse plate attached to the intake camshaft pulley passes over camshaft position (CMP) sensor A, a pulse signal is sent to the PCM.