Monitor Description
- Active Air fuel Ratio Control
The ECM usually performs air fuel ratio feedback control so that the air fuel ratio sensors output indicates a near stoichiometric air fuel ratio. This vehicle includes active air fuel ratio control in addition to regular air fuel ratio control. The ECM performs active air fuel ratio control to detect any deterioration in the Three-Way Catalytic Converter (TWC) and any malfunctions of the air fuel ratio sensor (sensor 2) (refer to the diagram below).
Active air fuel ratio control is performed for approximately 30 seconds while driving with a warm engine. During active air fuel ratio control, the air fuel ratio is forcibly regulated to become lean or rich by the ECM. If the ECM detects a malfunction, a DTC is stored.
- Abnormal Air Fuel Ratio Sensor (Sensor 2) Output Current (DTC P0136-16)
Case 1: The ECM illuminates the MIL and stores a DTC when active rich air-fuel ratio control is being performed and the air fuel ratio sensor (sensor 2) current is 6 mA or more.
Case 2: The ECM illuminates the MIL and stores a DTC when active rich air-fuel ratio control is being performed, the oxygen storage capacity of the catalyst is more than 1.52 g and the air fuel ratio sensor (sensor 2) current is -0.25696 mA or more.
- Abnormal Air Fuel Ratio Sensor (Sensor 2) Output Current During Fuel-cut from Rich Condition (DTC P013A-7C)
During a fuel cut, if the amount of time it takes for the current of the air fuel ratio sensor (sensor 2) to increase to a certain amount is equal to or greater than the threshold, the responsiveness of the air fuel ratio sensor (sensor 2) is judged as degraded, the ECM illuminates the MIL and stores a DTC.
