Toyota 2GR-FE Manual page 439

Sequence
First 0.02 inch leak pressure
B
measurement
EVAP system pressure
C
measurement
D EVAP VSV monitor
Second 0.02 inch leak pressure
E
measurement
F Final check
HINT:
*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
Operation A: Atmospheric Pressure Measurement
Purge VSV: OFF
Canister
0.02 Inch
Orifice
Vacuum
Pump: OFF
Operation C: EVAP System Pressure Measurement
OFF
ON
1. P0455: EVAP (Evaporative Emission ) gross leak
In operation C, the vacuum pump creates negative pressure (vacuum) in the EVAP system and the
EVAP system pressure is measured. If the stabilized system pressure is higher than [second 0.02 inch
leak pressure standard x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system
has a large leak, illuminates the MIL and sets the DTC (2 trip detection logic).
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Operation
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) created in EVAP system,
and EVAP system pressure then measured.
Write down measured value as they will be used in leak
check.
If EVAP pressure does not stabilize within 15 minutes,
ECM cancels EVAP system monitor.
EVAP VSV opened and then EVAP system pressure
measured by ECM.
Large increase indicates normal.
After second 0.02 inch leak pressure measurement,
leak check performed by comparing first and second
0.02 inch leak pressure standards.
If stabilized system pressure higher than second 0.02
inch leak pressure standard, ECM determines that
EVAP system leaking.
Atmospheric pressure measured and then monitoring
result recorded by ECM.
Fuel tank
Vent Valve: OFF (vent)
Pump Module
Air Filter
ON (closed)
Description
Operation B, E:
0.02 Inch Leak Pressure Measurement
OFF
Operation D: Purge VSV Monitor
ON
Atmospheric
Pressure
Negative
Pressure
ON
Duration
60 seconds
15 minutes*
10 seconds
60 seconds
-
OFF (vent)
ON
ON (closed)
ES–283
ES
A106055E15