| WARNING | Read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS . |
Circuit Description
Heated oxygen sensor No. 2 monitors exhaust gas oxygen content and delivers input signals to Engine Control Module (ECM). Heated oxygen sensor No. 2 is located on exhaust pipe behind catalytic converter and may also be referred to as bank No. 1 sensor No. 2, or rear oxygen sensor. ECM uses input signals to determine fuel injection system operation. DTC is set when heated oxygen sensor No. 2 output voltage remains at .45 volt or more, or .55 volt or less with vehicle at 25 MPH or more with engine at normal operating temperature. Possible causes are
- Heated oxygen sensor No. 2 circuit is open or shorted.
- Defective heated oxygen sensor No. 2.
Diagnostic Aids
Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.