Circuit Description

The vapor pressure sensor and VSV for canister closed valve (CCV) 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.

DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components within the dotted line in figure 1 below, or when there is malfunction in either the EVAP VSV or the vapor pressure sensor itself.

Fig 1: Evaporative Emission Control System Circuit Description (1 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Evaporative Emission Control System Circuit Description (2 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: DTC P0441 Detection Condition And Trouble Area

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Typical DTC output of each trouble part.

SCAN TOOL VALUES DESCRIPTION

Trouble Part

Trouble Condition

Typical DTC Output (⁽¹⁾)

Small Leak

P0442 and/or P0456 (⁽²⁾)

Medium Leak (ex: Vacuum hose looseness)

P0455

Large Leak (ex: Fuel tank cap looseness)

P0441 and P0455 and P0446

EVAP VSV

Open Malfunction

P0441

EVAP VSV

Close Malfunction

P0441 and P0446 and P0445

CCV

Open Malfunction

P0441 and P0446 and P0455

CCV

Close Malfunction

P0446

VSV for Purge Flow Switching

Open Malfunction

P0446

VSV for Purge Flow Switching

Close Malfunction

P0441 and P0446 and P0455

⁽¹⁾	ECM may output some other DTCs combination.

⁽²⁾	Refer to P0442 and P0456 DTC P0442 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (SMALL LEAK) DTC P0455 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (GROSS LEAK) DTC P0456 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (VERY SMALL LEAK) .