446 is an evap code.
The vapor pressure sensor, VSV for Canister Closed Valve (CCV), VSV for pressure switching valve are used to detect abnormalities in the evaporative emission control system.
The ECM decides whether or not there is an abnormality in the evaporative emission control system by 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 the VSV for EVAP, the VSV for pressure switching valve or in the vapor pressure sensor itself.
If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTC P0441, P0446, P0450 or P0451. If no other malfunctions than them are detected, troubleshoot DTC P0440 next.
Read freeze frame data using the TOYOTA hand-held tester or OBD II scan tool, as freeze frame data 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.
Thursday, January 2nd, 2020 AT 8:54 PM (Merged)