Monitor Description

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The ECM monitors for PCV system air leakage and suction.

If air leakage or suction occurs, air is sucked in by the intake vacuum during idling causing the air-fuel ratio to become lean and adjustment to the rich side to occur, and when air leaks due to boost pressure during turbocharging, the air-fuel ratio becomes rich and is adjusted to the lean side.

When the air fuel ratio is adjusted to the rich side during idling and adjusted to the lean side during turbocharging, it is determined that there is air leakage or suction in the PCV system.

If the air-fuel ratio calibration amount for the difference in air-fuel ratio when idling and when turbocharging exceeds the threshold, the ECM illuminates the MIL and stores a DTC (2 trip detection logic).