DTC Description

The PCM monitors rich-lean switching time of the rear Heated Oxygen Sensor (HO2S) after fuel cut-off to validate dynamic behavior of rear HO2S.

After detection of fuel cut-off engine operating state, the PCM measures rich-lean switching time of the rear HO2S signal and compares it to the specified limit value. When the switching time is bigger than the limit value, the PCM sets DTC P0139.