A23474
Purge VSV
(Vacuum Switching Valve)
EVAP Hose
(To Throttle Body)
EVAP Hose
(From Canister) Location of EVAP (Evaporative Emission) system:Vent ValveCanister
Pressure Sensor
Vacuum Pump
Purge Line
Fuel Tank
Air Inlet Port Breeding
PipeFuel Tank Cap Refueling ValvePump Module
Air Filter
A23668
EVAP System Circuit:
Intake Manifold
Purge VSV
Cut±Off Valve Roll±Over Valve
CanisterAir Filterfuel tank cap
Service Port
Air Cleaner
Restrictor (0.08 inch)
Refueling Valve Throttle Valve
ECM
Soak Timer
Pump Module
Fuel Tank
± DIAGNOSTICSENGINE
DI±461
655 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
While the engine is running, if a predetermined condition (closed±loop, etc.) is met, the purge VSV is opened
by the ECM and stored fuel vapors in the canister are purged to the intake manifold. The ECM changes the
duty cycle ratio of the purge VSV to control purge flow volume.
The purge flow volume is also determined by the intake manifold pressure.
Atmospheric pressure is allowed
into the canister through the vent valve to ensure that the purge flow is maintained when the negative pres-
sure (vacuum) is applied to the canister.
The following two monitors run to confirm appropriate EVAP system operation.
