Diagnosis & Repair
- If DTC P0441 (purge flow), P0446 (VSV for CCV or VSV for pressure switching valve), P0451, P0452 or P0453 (evaporative pressure sensor) is output with DTC P0442 or P0456, first trouble shoot DTC P0441, P0446, P0451, P0452 or P0453. If no malfunction is detected, trouble shoot DTC P0442 or P0456 next.
- If different DTCs that are related to different systems are output simultaneously while terminal E2 is used a s a ground terminal, terminal E2 may be open.
- Read freeze frame data using OBD II scan tool or hand-held tester. Because freeze frame records the engine conditions when the malfunction is detected. When trouble shooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
- When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.
For wiring diagram, see DTC P0442: EVAP SYSTEM LEAK DETECTED (SMALL LEAK) & DTC P0456: EVAP SYSTEM LEAK DETECTED (VERY SMALL LEAK) . For diagnosis and repair with Toyota hand-held tester, see Fig 1-Fig 19 . For diagnosis and repair with OBD II scan tool, see Fig 20-Fig 26 .
For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. To identify circuits referenced in testing, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article. To check ECM inputs and outputs, see PIN VOLTAGE CHARTS article. For ECM location, see ENGINE CONTROL MODULE LOCATION under SELF-DIAGNOSTIC SYSTEM.