P0446

P0446 - Evaporative Emission Control System Vent Control Malfunction

CIRCUIT DESCRIPTION

DTC Detection Condition:

The vapor pressure sensor and VSV for vapor pressure sensor 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 Fig. 1, or when there is a malfunction in either the VSV for EVAP, the VSV for vapor pressure sensor, or in the vapor pressure sensor itself.

Wiring Diagram:

INSPECTION PROCEDURE

HINT:
- If DTC P0441, P0446, or P0450 or P0451 is output after DTC P0440, first troubleshoot DTCs P0441, P0446 or P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.
- Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

Steps 1 - 3:

Step 4:

Steps 5 - 6:

Step 7:

Steps 8 - 9:

Steps 10 - 12:

Steps 13 - 14:

Steps 15 - 16:

TOYOTA hand-held tester

Step 1:

Steps 2 - 5:

Steps 6 - 8:

Steps 9 - 10:

Step 11:

OBD II scan tool (excluding TOYOTA hand-held tester)