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.
The 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 P0451, P0452 or P0453 is recorded by the ECM when the vapor pressure sensor malfunctions. See Figure. Possible causes are:
- Open or short in vapor pressor sensor circuit.
- Faulty vapor pressure sensor.
- Faulty ECM.