ENGINE - 1NZ-FE ENGINE
00REG23Y
To Intake Manifold
Atmosphere
Purge VSV
(Open)
ECM
00REG24Y
Close
Open
EG-50
System Operation
1) Purge Flow Control
When the engine has reached predetermined parameters (closed loop, engine coolant temperature above
74
C (165
F), etc.), stored fuel vapors are purged from the canister whenever the purge VSV is opened
by the ECM.
The ECM will change the duty ratio cycle of the purge VSV, thus controlling purge flow volume. Purge
flow volume is determined by intake manifold pressure and the duty ratio cycle of the purge VSV.
Atmospheric pressure is allowed into the canister to ensure that purge flow is constantly maintained
whenever purge vacuum is applied to the canister.
2) ORVR (On-Board Refueling Vapor Recovery)
When the internal pressure of the fuel tank increases during refueling, this pressure causes the diaphragm
in the refueling valve to lift up, allowing the fuel vapors to enter the canister. Because the vent valve is
always open (even when the engine is stopped) when the system is in a mode other than the monitoring
mode, the air that has been cleaned through the canister is discharged outside the vehicle via the fresh
air line. If the vehicle is refueled in the monitoring mode, the ECM will recognize the refueling by way
of the canister pressure sensor, which detects the sudden pressure increase in the fuel tank, and will open
the vent valve.
Summary of Contents for 1NZ-FE
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