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DTC - Diagnostic Trouble Codes information

P0451

Powertrain Codes

P0451 - TOYOTA - Evaporative Emission Control System Pressure Sensor Range/Performance

Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

- Vapor Pressure Sensor harness is open or shorted - Vapor pressure sensor circuit poor electrical connection - Faulty Vapor pressure sensor - Faulty Engine Control Module (ECM)

When Detected

Vapor pressure sensor output extremely changes under conditions of (a) and (b): (2 trip detection logic) - Vehicle speed: 0 km/h (0mph), Engine speed: Idling and VSV for pressure switching valve is OFF - Vapor pressure sensor value opening pressure valve of charcoal canister

Description

The vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for 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 is recorded by the ECM when the vapor pressure sensor malfunction.