PGM-FI System Description - A/F Sensor/HO2S Feedback Air/Fuel Ratio Control
ir fuel ratio control is part of fuel injection control and comprises the steps of
Calculating basic injection amount from intake air flow amount and engine speed
Calculating air fuel ratio correction value from the oxygen density in the exhaust gas and reflecting the calculated values to the
ir fuel ratio control stops feedback under the following conditions in order to maintain operational performance and catalytic
When starting the engine or during fuel increase after the engine is started
While the engine coolant is cold
During fuel increase under high load
During fuel increase at high engine speed
During fuel cut-off at deceleration
Air Fuel Ratio (A/F) Sensor (Sensor 1)
ir 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.
PGM-FI System Description - A/F Sensor/HO2S Feedback Air/Fuel Rat... http://techinfo.honda.com/rjanisis/pubs/sm/1/2/Contents/enu/61TBAD/...
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