Diagnosis & Repair
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:
Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records engine conditions when malfunction is detected, when trouble shooting it is useful for determining whether vehicle was running or stopped, engine warmed up or not, air-fuel ratio lean or rich, etc. at time of malfunction.
For wiring diagram, see DTC P0125: INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL . For diagnosis and repair, see Fig 1 and Fig 2 . To check ECM inputs and outputs, see PIN VOLTAGE CHARTS article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article. To identify circuits referenced in testing, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAM article. To check ECM power source circuit, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article.