Toyota 2GR-FE Manual page 420

ES–264
Sequence
Atmospheric pressure
A
measurement
First 0.02 inch leak pressure
B
measurement
EVAP system pressure
C
measurement
D Purge VSV monitor
ES
Second 0.02 inch leak pressure
E
measurement
F Final check
*2
: If there is only a small amount of fuel in the fuel tank, stabilizing the EVAP pressure takes longer than
usual.
Operation A:
Atmospheric Pressure Measurement
Purge VSV:
OFF
0.02 Inch Orifice
Pressure Sensor
Vacuum Pump: OFF
Operation C: EVAP System Pressure Measurement
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Operations
Vent valve turned OFF (vent) and EVAP system pressure measured
by ECM in order to register atmospheric pressure.
If pressure in EVAP system is not between 70 kPa and 110 kPa (525
mmHg and 825 mmHg), ECM cancels EVAP system monitor.
In order to determine 0.02 inch leak pressure standard, vacuum pump
creates negative pressure (vacuum) through 0.02 inch orifice and then
ECM checks if vacuum pump and vent valve operate normally.
Vent valve turned ON (closed) to shut EVAP system.
Negative pressure (vacuum) is created in EVAP system, and EVAP
system pressure then measured. Write down measured value as it will
be used in leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM cancels
EVAP system monitor.
Purge VSV is opened and then EVAP system pressure is measured
by ECM.
Large increase indicates normal.
After second 0.02 inch leak pressure measurement, leak check is
performed by comparing first and second 0.02 inch leak pressure
standards.
If stabilized system pressure is higher than second 0.02 inch leak
pressure standard, ECM determines that EVAP system leaking.
Atmospheric pressure is measured and then monitoring result is
recorded by ECM.
Canister
Vent Valve: OFF (vent)
Air Filter
OFF
ON
Descriptions
Operation B, E:
0.02 Inch Leak Pressure Measurement
Fuel Tank
Pump Module
ON (closed)
Atmospheric
Pressure
Negative
Pressure
10 seconds
60 seconds
15 minutes
10 seconds
60 seconds
OFF
ON
Operation D: Purge VSV Monitor
ON
ON
Duration
*2
-
OFF
(vent)
ON
(closed)
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