DTC P2A03 (2017 2018 2019): General Description
The front air/fuel ratio (A/F) sensor (bank 2, sensor 1) has a linear signal output in relation to the oxygen concentration. The powertrain control module (PCM) computes the air/fuel ratio from the front A/F sensor (bank 2, sensor 1) output voltage and uses the fuel feedback control to improve exhaust emissions. The PCM monitors the front A/F sensor (bank 2, sensor 1) output voltage during deceleration with the throttle fully closed, and if the output voltage deviates greatly from normal oxygen concentration levels, it detects a malfunction and stores a DTC.
Note:Output to the scan tool exhibits a relationship between the front A/F sensor (bank 2, sensor 1) output and oxygen concentration, which is opposite to the characteristic shown in the graph. That is, a deviation toward the rich side increases the output voltage and one toward the lean side decreases the output voltage, as the stoichiometric ratio is 0.