Circuit Description
Vapor pressure sensor and Vacuum Switching Valve (VSV) for vapor pressure sensor are used to detect faults in EVAP system. DTC P0440 is set if EVAP system leak is detected or vapor pressure sensor malfunctions (detection of atmospheric pressure in fuel tank, after vehicle has been driven for 20 minutes). Possible causes are:
- Vapor pressure sensor.
- Fuel tank cap installed incorrectly.
- Fuel tank cap defective.
- Damaged, disconnected or blocked vacuum hose.
- Fuel tank damaged.
- Charcoal canister damaged.
- Hoses between fuel tank and charcoal canister damaged.
NOTE:
If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, perform that diagnostic circuit test before performing DTC P0440 test.