Circuit Description
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
Vapor pressure sensor, the VSV for the Canister Closed Valve (CCV) and the VSV for the pressure switching valve are used to detect abnormalities in the evaporative emission control system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. DTC P0442 and P0456 are recorded by the ECM when the evaporative emissions leak from the components shown in illustration, or when the vapor pressure sensor malfunctions. See Figure and Fig 1 . Possible causes are:
- Hose or tube cracked, damaged or loose seal.
- Fuel tank cap incorrectly installed.
- Fuel tank cap cracked or damaged.
- Vacuum hose.
- Fuel tank cracked or damaged.
- Charcoal canister cracked or damaged.
- Open or short in vapor pressure sensor circuit.
- Vapor pressure sensor.
- Fuel tank over fill check valve cracked or damaged.
- Faulty ECM.