Circuit Description

WARNING: This page is about a different car, the 2003 Toyota Matrix and 2003 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Bank No. 1 refers to bank that includes cylinder No. 1.
Sensor No. 1 refers to sensor closer to engine body.
The oxygen sensor's output voltage and short-term fuel trim value can be read using hand-held tester or OBD II scan tool.

For circuit description, see DTC P0125: INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL . Detecting condition of DTC is when response time for oxygen sensor's voltage output to change from rich to lean, or from lean to rich, is 1 second (Corolla and Matrix 1ZZ-FE engine) or 0.8 second (Matrix 2ZZ-GE engine) or more during idling after engine is warmed up (2 trip detection logic).