Monitor Description

Sensor Voltage Detection Monitor: 

Under air fuel ratio feedback control, If the air fuel ratio sensor output voltage is less than 2.8 V (very rich condition) for 5 seconds despite the heated oxygen sensor output voltage being less than 0.7 V, the ECM stores DTC P2196-23 or P2198-23. Alternatively, if the air fuel ratio sensor output voltage is higher than 3.8 V (very lean condition) for 5 seconds despite the heated oxygen sensor output voltage being 0.21 V or higher, DTC P2195-24 or P2197-24 is stored.

Sensor Current Detection Monitor: 

A rich air fuel mixture causes a low air fuel ratio sensor current, and a lean air fuel mixture causes a high air fuel ratio sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the air fuel ratio sensor current during fuel-cut and detects any abnormal current values.

If the air fuel ratio sensor output is 2.2 mA or higher for 3 seconds or more of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and stores DTC P2195-19 or 219719 (stuck on high side). If the air fuel ratio sensor output is less than 0.47 mA for 3 seconds or more of cumulative time, the ECM stores DTC P2196-18 or P2198-18 (stuck on low side).

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