Toyota 2GR-FE Manual page 427

(a) EVAP VSV stuck open
In operation C, the vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative
Emission) system. The EVAP system pressure is then measured by the ECM using the pressure
sensor. If the stabilized system pressure is higher than [second 0.02 inch leak pressure standard
x 0.2], the ECM interprets this as the EVAP VSV (Vacuum Switching Valve) being stuck open.
The ECM illuminates the MIL and sets the DTC (2 trip detection logic).
EVAP Pressure when VSV (for EVAP) Stuck Open:
VSV (for EVAP)
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Negative
First 0.02 Inch
Leak Pressure
Standard
Sequence
A
Time
10 seconds
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
B
60 Within 15 minutes
seconds
ON
ON
ON
Malfunction
OK
C D
10
seconds
ES–271
ON: Open
OFF: Closed
ON: Closed
ON: Vent
[Second 0.02
Inch Leak
Pressure
Standard] x 0.2
E
60
seconds
A108008E11
ES