Oxygen Sensor Diagnosis

Oxygen Sensor Diagnosis

The Fuel Control Heated Oxygen Sensor (HO2S 1) is diagnosed for the following conditions:

^ The Heater Performance (time to activity on cold start)

^ A Slow Response

^ The Response Time (time to switch R/L or L/R)

^ An Inactive Signal (output steady at bias voltage - approximately 450 mV)

^ A Signal Fixed High

^ A Signal Fixed Low

The Catalyst Monitor Heated Oxygen Sensor (HO2S 2) is diagnosed for the following functions:

^ The Heater Performance (the time to activity on a cold start)

^ The Signal fixed low during steady state conditions or power enrichment (a hard acceleration when a rich mixture should be indicated).

^ The Signal fixed high during steady state conditions or a decel fuel mode (deceleration when a lean mixture should be indicated)

^ An Inactive Sensor (output steady at approximately 438 mV)