Toyota 2GR-FE Manual page 440

ES–284
2. P0456: EVAP very small 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 the second 0.02
inch leak pressure standard, the ECM determines that the EVAP system has a small leak, illuminates
the MIL and sets the DTC (2 trip detection logic).
EVAP Pressure when EVAP System Leaks:
VSV (for EVAP)
Vent Valve
ES
Vacuum Pump
EVAP Pressure
Positive
Negative
First 0.02 Inch
Leak Pressure
Standard
Sequence
Time
MONITOR STRATEGY
Required Sensors/Components
Frequency of Operation
Duration
MIL Operation
Sequence of Operation
TYPICAL ENABLING CONDITIONS
EVAP key-off monitor runs when all of following conditions are met:
Atmospheric pressure
Battery voltage
Vehicle speed
Engine switch
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
A B
10 seconds 60
seconds
ON
ON
P0455
P0456
OK
C
Within 15 minutes
EVAP VSV and pump module
Once per driving cycle
Within 15 minutes (varies with amount of fuel in tank)
2 driving cycles
None
-
70 to 110 kPa (525 to 825 mmHg)
10.5 V or more
Below 2.5 mph (4 km/h)
OFF
ON: Open
ON
OFF: Closed
ON: Closed
ON: Vent
D E
60 seconds
10 seconds
A129400E02