Detection Condition

PCM monitors front HO2S input voltage during drive mode 3 when following monitoring conditions are met:

Monitoring Conditions

• Engine speed is more than 1500 RPM.
• Engine coolant temperature has reached 158°F (70°C).

If input voltage from HO2S circuit never exceeds .55 volt for 94 seconds, PCM determines sensor circuit is not activated. This is a continuous monitor. MIL illuminates if PCM detects malfunction in 2 consecutive drive cycles.