Toyota 2GR-FE Manual page 428

ES–272
(b) EVAP VSV stuck closed
In operation D, the pressure sensor measures the EVAP (Evaporative Emission) system
pressure. The pressure measurement for EVAP VSV monitor is begun when the EVAP VSV is
turned ON (open) after the EVAP leak check. When the measured pressure indicates an
increase of 0.3 kPa (2.25 mmHg) or more, the EVAP VSV is functioning normally. If the pressure
does not increase, the ECM interprets this as the EVAP VSV being stuck closed. The ECM
illuminates the MIL and sets the DTC (2 trip detection logic).
EVAP Pressure when VSV (for EVAP) Stuck Closed:
VSV (for EVAP)
Vent Valve
ES
Vacuum Pump
EVAP Pressure
Positive
Negative
First 0.02 Inch
Leak Pressure
Standard
Sequence
Time
EVAP Pressure During Purge Flow Monitor:
VSV (for
EVAP)
Vent Valve
EVAP
Pressure
1st Monitor
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
A B
60
10 seconds
seconds
Open
ON
(Closed)
Malfunction
0.1 kPa
OK
0.5 kPa
OK
2nd Monitor
A071563E14
ON
ON
OK
Malfunction
C
Within 15 minutes
2. PURGE FLOW MONITOR
The purge flow monitor consists of the two step monitors.
The 1st monitor is conducted every time and the 2nd
monitor is activated if necessary.
• The 1st monitor
While the engine is running and the EVAP VSV
(vacuum Switching Valve) is ON (open), the ECM
monitors the purge flow by measuring the EVAP
pressure change. If negative pressure is not created,
the ECM begins the 2nd monitor.
• The 2nd monitor
The vent valve is turned ON (closed) and the EVAP
pressure is then measured. If the variation in the
pressure is less than 0.5 kPa (3.75 mmHg), the ECM
interprets this as the EVAP VSV being stuck closed,
and illuminates the MIL and sets DTC P0441 (2 trip
detection logic).
Atmospheric pressure check:
ON: Open
ON
OFF: Closed
ON: Closed
ON: Vent
E
D
10 60
seconds seconds
A106059E09