Monitor Description

Function Explanation (DTC Detection Outline) 

• The ECM detects the oxygen concentration in the exhaust gas based on the A/F sensor signal. By intentionally increasing/decreasing the fuel injection amount, the ECM controls the oxygen concentration in the exhaust gas to rich or lean and monitors the response speed of the A/F sensor to sudden changes in the oxygen concentration. If the response speed of the signal input from the A/F sensor is slow while switching repeatedly between rich and lean, the ECM determines an A/F sensor malfunction and stores a DTC.

Fig 1: Fuel Injection And A/F Sensor DTC Detection Outline Graph

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