Toyota Camry Hybrid AHV40 Manual page 254

EG-66
"
Fuel Tank Internal Pressure Equals Atmospheric Pressure
Vent Valve (Vent / Close)
Leak Detection Pump (ON / OFF)
Purge VSV (Open / Close)
Fuel Vapor-containment Valve
Fuel Tank Pressure Sensor
Atmospheric Pressure (0 kPa)
Canister Pressure Sensor
at Leak Detection Pump
Order Operation
Atmospheric Pressure Atmospheric Pressure
1
1
Measurement
0.02 in. Leak Pressure 0.02 in. Leak Pressure
2 2
Measurement
3 3 Canister Leak Check Canister Leak Check
Purge VSV Monitor Purge VSV Monitor
and Fuel and Fuel
4 4 Vapor containment Vapor-containment
Valve Stuck Closed
Judgment
0.02 in. Leak Pressure 0 02 in Leak Pressure
Measurement and
5
Format Format
Fuel
Vapor-containment V
Valve Stuck Closed Valve Stuck Closed
6 6
Judgment and Fuel
Tank Leakage Tank Leakage
Judgment
0.02 in. Leak Pressure 0.02 in. Leak Pressure
7 7
Measurement
8 Final Check
ENGINE - 2AZ-FXE ENGINE
(Open / Close)
1
THS ECU turns vent valve OFF (vent) and measures EVAP THS ECU turns vent valve OFF (vent) and measures EVAP
control system pressure to memorize atmospheric pressure.
Leak detection pump creates negative pressure (vacuum)
through 0 02 in orifice and pressure is measured THS ECU through 0.02 in. orifice and pressure is measured. THS ECU
determines this as 0.02 in. leak pressure.
Leak detection pump creates negative pressure (vacuum) in
canister leak check and canister leak check pressure is
measured. If stabilized pressure is larger than 0.02 in. leak measured. If stabilized pressure is larger than 0.02 in. leak
pressure, THS ECU determines EVAP control system has leak.
If leak detection pump pressure does not stabilize within 15
minutes, THS ECU cancels EVAP monitor.
THS ECU opens purge VSV and measures EVAP control THS ECU opens purge VSV and measures EVAP control
system pressure increase. If increase is large, THS ECU system pressure increase. If increase is large, THS ECU
interprets this as normal. p
Leak detection pump creates negative pressure (vacuum)
through 0.02 in. orifice and pressure is measured. THS ECU through 0 02 in orifice and pressure is measured THS ECU
determines this as 0.02 in. leak pressure.
THS ECU turns vent valve OFF (vent) and measures canister THS ECU t
leak check pressure to memorize atmospheric pressure.
t i t
Leak detection pump creates a negative pressure (vacuum) in
the fuel tank and the THS ECU measures the pressure at the the fuel tank and the THS ECU measures the pressure at the
time the fuel vapor containment valve is opened. time the fuel vapor-containment valve is opened.
Leak detection pump creates negative pressure (vacuum)
through 0.02 in. orifice and pressure is measured. THS ECU through 0 02 in orifice and pressure is measured THS ECU
determines this as 0.02 in. leak pressure.
THS ECU measures atmospheric pressure and records monitor
result.
A
2 3 4 5 6
Description
t l OFF ( t) d
7 8
02HEG35Y
Time
10 sec
10 sec.
60 sec 60 sec.
Within Within
15 min.
10 sec. 10 sec.
60 sec. 60 sec
and
10 sec. 10 sec
i t
Approx. Approx.
15 min.
60 sec. 60 sec
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