Toyota Celica 2005 Repair Manual page 723

DI−524
DTC P0442
DTC P0456
CIRCUIT DESCRIPTION
The vapor pressure sensor, canister closed valve (CCV) and 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 or P0456 is recorded by the ECM when evaporative emissions leak from the components within
the dotted line in Fig. 1 below, or when the vapor pressure sensor malfunctions.
Fig. 1
CCV
(7)
2005 CELICA (RM1131U)
DIAGNOSTICS
Evaporative Emission Control System Leak
Detected (Small Leak)
Evaporative Emission Control System Leak
Detected (Very Small Leak)
(6)
EVAP
VSV
(4)
(5)
(8)
Charcoal Canister
− ENGINE (2ZZ−GE)
ECM
Pressure
Switching
Valve
(3)
722
Vapor Pressure
Sensor
Fuel Tank Over
Fill Check Valve
(1)
(10)
(2)
(11)
(9)
Fuel Tank
DIC7M−02
A21577