Note. Bank No. 1 refers to bank which includes cylinder No. 1. Heated oxygen sensor No. 2 refers to sensor farthest from engine block.
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
Heated oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses input signal to determine fuel injection system operation. Heated oxygen sensors include a heater. DTC is set when bank No. 1, sensor No. 2 voltage remains at .4 volt or more, or .5 volt or less (.6 volt or less on all except California emissions) during vehicle operation (31 MPH or more), once engine is at normal operating temperature. Possible cause is
- Defective heated oxygen sensor No. 2.
Diagnostic Aids
Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.