| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
Vapor pressure sensor and Vacuum Switching Valve (VSV) for vapor pressure sensor are used to detect faults in EVAP system.
DTC is set if EVAP system leak is detected or vapor pressure sensor malfunctions. Possible causes are
- Fuel pressure sensor.
- Fuel tank cap installed incorrectly.
- Fuel tank cap defective.
- Damaged, disconnected or blocked vacuum hose.
- Fuel tank damaged.
- Charcoal canister.
Note. If DTC P0441, P0446 or P0450 is output after DTC P0440, perform appropriate circuit test first before performing DTC P0440 test.