Set Condition
Cold start - the Oxygen Sensor signal voltage is below 0.05 volts and greater than -1.00 volts for a calibrated period of time. Closed loop operation - if the closed loop fuel trim is clamped rich and the sensor output voltage is below 0.05 volts but greater than -1.00 volts for a calibrated period of time. This is a two trip fault. Three good trips are required to turn off the MIL.