Malfunction Threshold

Either of the condition occurs:

• The voltage level of the SO2HTB1 terminal is OFF (high voltage) for at least 5 seconds despite the PCM outputs ON signal to rear secondary HO2S (sensor 2).
• The rear secondary HO2S (sensor 2) output driver in the PCM detects an over current for at least 5 seconds when the PCM outputs ON signal to rear secondary HO2S (sensor 2).