Note. For circuit reference, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For component locations, see COMPONENT LOCATIONS . For connector identification, see CONNECTOR IDENTIFICATION .
Circuit Description
The DTC P0133 Heated Oxygen Sensor (HO2S) Slow Response Sensor 1 diagnostic detects an unresponsive oxygen sensor. The Powertrain Control Module (PCM) continuously monitors HO2S activity. PCM counts the number of times that a rich-to-lean and lean-to-rich response is indicated and adds amount of time required to complete all the transitions. PCM uses this information to determine an average time for each transition. A DTC P0133 will set if the average transition time is too slow.
A lean-to-rich transition is indicated when the HO2S voltage changes from less than 300 mV to more than 600 mV. A rich-to-lean transition is indicated when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly may be faulty and should be replaced. See HO2S OPERATION table.