TOYOTA SIENNA 2007 Service Repair Manual

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–415
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$3D $CE Multiply by 0.01 [kPa]Test value for vent valve stuck OFF
(vent) (P2420)
Refer to pressure C*Minimum test limit for
vent valve stuck ONMaximum test limit for
vent valve stuck ON
$3D $CF Multiply by 0.01 [kPa]Test value for vent valve stuck ON
(P2419)
Refer to pressure A*Minimum test limit for
vent valve stuck OFFMaximum test limit for
vent valve stuck OFF
$3D $D0 Multiply by 0.01 [kPa]Test value for 0.02 inch orifice low flow
(P043E)
Refer to pressure B*Minimum test limit for
0.02 inch orifice low
flowMaximum test limit for
0.02 inch orifice low
flow
$3D $D1 Multiply by 0.01 [kPa]Test value for 0.02 inch orifice high flow
(P043F)
Refer to pressure A*Minimum test limit for
0.02 inch orifice high
flowMaximum test limit for
0.02 inch orifice high
flow
$3D $D4 Multiply by 0.01 [kPa]Test value for purge VSV stuck closed
(P0441)
Refer to pressure F*Minimum test limit for
purge VSV stuck
closedMaximum test limit for
purge VSV stuck
closed
$3D $D5 Multiply by 0.01 [kPa]Test value for purge VSV stuck open
(P0441)
Refer to pressure E*Minimum test limit for
purge VSV stuck
openMaximum test limit for
purge VSV stuck
open
$3D $D7 Multiply by 0.01 [kPa]Test value for purge flow (P0441)
Refer to pressure G*Minimum test limit for
purge flowMaximum test limit for
purge flow MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit

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* Pressures A to G are indicated as shown in the diagram below.
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DESCRIPTION
While the engine is running, if a predetermined condition (closed-loop, etc.) is met, the purge VSV is
opened by the ECM and fuel vapors stored in the canister are purged to the intake manifold. The ECM
changes the duty cycle ratio of the purge VSV to control purge flow volume.
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The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is
allowed into the canister through the vent valve to ensure that the purge flow is maintained when negative
pressure (vacuum) is applied to the canister.
The following two monitors run to confirm appropriate EVAP system operation.
1. Key-off monitor
This monitor checks for EVAP (Evaporative Emission) system leaks and pump module malfunctions.
The monitor starts 5 hours* after the ignition switch is turned off. More than 5 hours are required to
allow the fuel to cool down to stabilize the Fuel Tank Pressure (FTP), thus making the EVAP system
monitor more accurate.
The electric vacuum pump creates negative pressure (vacuum) in the EVAP system, and the
pressure is measured. Finally, the ECM monitors for leaks from the EVAP system and malfunctions in
both the pump module and purge VSV, based on the EVAP pressure.
HINT:
*: If the engine coolant temperature is not below 35
C (95F) 5 hours after the ignition switch is
turned off, the monitor check starts 2 hours later. If it is still not below 35
C (95F) 7 hours after the
ignition switch is turned off, the monitor check starts 2.5 hours later.
2. Purge flow monitor
The purge flow monitor consists of the two monitors. The 1st monitor is always conducted every time
and the 2nd monitor is activated if necessary.
• The 1st monitor
While the engine is running and the purge 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 OFF (open) 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 purge VSV being
stuck closed, and illuminates the MIL and sets DTC P0441 (2 trip detection logic).
Atmospheric pressure check:
In order to ensure reliable malfunction detection, the variation between the atmospheric pressures,
before and after conduction of the purge flow monitor, is measured by the ECM.
Component Operation
Canister Contains activated charcoal to absorb EVAP (Evaporative Emissions) generated in fuel tank.
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Cut-off valve Located in fuel tank. Valve floats and closes when fuel tank is 100% full.
Purge VSV (Vacuum Switching Valve)Opens or closes line between canister and intake manifold. ECM uses purge VSV to control EVAP
purge flow. In order to discharge EVAP absorbed by canister to intake manifold, ECM opens purge
VSV. EVAP discharge volume to intake manifold is controlled by purge VSV duty cycle ratio
(current-carrying time). (Open: ON, Close: OFF)
Refueling valveControls EVAP pressure from fuel tank to canister. Valve consists of diaphragm, spring and
restrictor (diameter: 0.08 inch). When fuel vapor and pressure inside fuel tank increase, valve
opens. While EVAP is purged, valve closes and restrictor prevents a large amount of vacuum from
affecting pressure in fuel tank. Valve is opened while refueling. When valve is open, adding fuel into
fuel tank is possible.
Roll-over valveLocated in fuel tank. Valve closes by its own weight when vehicle overturns to prevent fuel from
spilling out.
Service port Used for connecting vacuum gauge for inspecting EVAP system.
Soak timerBuilt into ECM. To ensure accurate EVAP monitor, measures 5 hours (+/- 15 min.) after ignition
switch is turned off. This allows fuel to cool down, stabilizing Fuel Tank Pressure (FTP). When
approx. 5 hours elapsed, ECM activates.
Canister pump module Consists of (a) to (d) below. Pump module cannot be disassembled.
(a) Vent valveVents and closes EVAP system. When ECM turns valve ON, EVAP system is closed. When ECM
turns valve OFF, EVAP system is vented. Negative pressure (vacuum) is created in EVAP system
to check for EVAP leaks by closing purge VSV and vent valve (closed), and operating vacuum
pump are turned on (refer to fig. 1).
(b) Canister pressure sensorIndicates pressure as voltages. ECM supplies regulated 5 V to pressure sensor, and uses feedback
from sensor to monitor EVAP system pressure (refer to fig 2).
(c) Vacuum pump Creates negative pressure (vacuum) in EVAP system for leak check.
(d) 0.02 inch orificeHas an opening with 0.02 inch diameter. Vacuum is produced through orifice by closing purge VSV,
turning off vent valve and operating vacuum pump, to monitor 0.02 inch leak pressure. 0.02 inch
leak pressure indicates a small leak of EVAP. Component Operation

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WIRING DIAGRAM
Refer to DTC P0450 (See page ES-272).
INSPECTION PROCEDURE
NOTICE:
An intelligent tester is required to conduct the following diagnostic troubleshooting procedure.
HINT:
• Using intelligent tester monitor results enables the EVAP (Evaporative Emission) system to be
confirmed.
• Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame
data can be helpful in determining whether the vehicle was running or stopped, whether the engine
was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the
time of a malfunction.
(a) Turn the ignition switch off and wait for 10 seconds.
(b) Turn the ignition switch to the ON position.
1CONFIRM DTC
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(c) Turn the ignition switch off and wait for 10 seconds.
(d) Connect the intelligent tester to the DLC3.
(e) Turn the ignition switch to the ON position and turn the
tester on.
(f) Select the following menus: DIAGNOSIS / ENHANCED
OBD II / DTC INFO / CURRENT CODES.
(g) Confirm DTCs and freeze frame data.
If any EVAP system DTCs are set, the malfunctioning
area can be determined using the table below.
NOTICE:
If the 0.02 inch reference pressure difference
between the first and second checks is greater than
the specification, the DTCs corresponding to the
reference pressure (P043E, P043F, P0441, P0455,
P0456, P2401 and P2420) will all be stored.
NEXT
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NOTICE:
• In the EVAP SYSTEM CHECK (AUTO OPERATION), the
series of 5 EVAP SYSTEM CHECK steps is performed
automatically by the intelligent tester. It takes a
maximum of approximately 18 minutes.
• Do not perform the EVAP SYSTEM CHECK when the
fuel tank is more than 90% full because the cut-off
valve may be closed, making the leak check of the fuel
tank unavailable.
• Do not run the engine in this step.
• When the temperature of the fuel is 35
C (95F) or
more, a large amount of vapor forms and any check
results become inaccurate. When performing the
EVAP SYSTEM CHECK, keep the temperature below
35
C (95F).
(a) Connect the intelligent tester to the DLC3.
(b) Clear the DTCs (See page ES-39).
(c) Select the following menu items on the tester:
DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK /
EVAP SYS CHECK / AUTO OPERATION.
(d) After the EVAP SYSTEM CHECK is completed, check
for pending DTCs by selecting the following menu items:
DIAGNOSIS / ENHANCED OBD II / DTC INFO /
PENDING CODES.
HINT:
If no pending DTC is displayed, perform the Monitor
Confirmation after this repair is completed. After this
confirmation, check for pending DTCs. If no DTC is
displayed, the EVAP system is normal.
NEXT
2PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–423
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NOTICE:
• In the EVAP SYSTEM CHECK (MANUAL OPERATION),
the series of 5 EVAP SYSTEM CHECK steps is
performed manually by the intelligent tester.
• Do not perform the EVAP SYSTEM CHECK when the
fuel tank is more than 90% full because the cut-off
valve may be closed, making the leak check of the fuel
tank unavailable.
• Do not run the engine in this step.
• When the temperature of the fuel is 35
C (95F) or
more, a large amount of vapor forms and any check
results become inaccurate. When performing the
EVAP SYSTEM CHECK, keep the temperature below
35
C (95F).
(a) Connect the intelligent tester to the DLC3.
(b) Clear the DTCs (See page ES-39).
(c) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / SYSTEM CHECK / EVAP SYS
CHECK / MANUAL OPERATION.
NEXT
3PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION)
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ES–4242GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
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(a) Check the EVAP pressure in step 1/5.
Result
*: The DTCs relating to the EVAP system displayed on
the intelligent tester when checking.
B
A
4PERFORM EVAP SYSTEM CHECK (STEP 1/5)
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DTC* Test Result Suspected Trouble Area Proceed to
- Virtually no variation in EVAP pressure Not yet determined A
P0451EVAP pressure fluctuates by +/-0.3 kPa (2.25
mmHg) or morePressure sensor noising B
Go to step 30