Circuit Description

WARNING: This page is about a different car, the 2003 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.

Vapor pressure sensor, VSV for Canister Closed Valve (CCV) and VSV for pressure switching valve are used to detect abnormalities in evaporative emission control system. ECM decides whether there is an abnormality in evaporative emission control system based on vapor pressure sensor signal. DTCs P0451, P0452 or P0453 is recorded by ECM when vapor pressure sensor malfunctions or ECM malfunctions.

DTC P0451 is set when vapor pressure sensor output change is extreme when vehicle is stopped, engine speed is idle and VSV for pressure switching valve is off. Vapor pressure sensor value is equal to or greater than opening pressure value of charcoal canister.

DTC P0452 is set when there is an open in vapor pressure sensor circuit. DTC P0453 is set when there is a short in vapor pressure sensor circuit.