TOYOTA RAV4 2006 Service Workshop Manual

ENGINE - 2AZ-FE ENGINE
Service Tip
The canister pump module performs the EVAP leak check. This check is done approximately five
hours after the engine is turned off. So you may hear sound coming from underneath the luggage
compartment for several minutes. It does not indicate a malfunction.
The pinpoint pressure test procedure is carried out by pressurizing the fresh air line that runs from
the pump module to the air filler neck. For details, refer to the 2006 RAV4 Repair Manual (Pub.
No. RM01M1U).
EG-54
10. EVAP (evaporative Emission) Control System
General
The EVAP (evaporative emission) control system prevents the vapor gas that is created in the fuel tank from
being released directly into the atmosphere.
The canister stores the vapor gas that has been created in the fuel tank.
The ECM controls the purge VSV in accordance with the driving conditions in order to direct the vapor
gas into the engine, where it is burned.
In this system, the ECM checks the evaporative emission leak and outputs DTC (Diagnostic Trouble
Code) in the event of a malfunction. An EVAP (evaporative emission) leak check consists of an
application of a vacuum pressure to the system and monitoring the changes in the system pressure in order
to detect a leakage.
This system consists of the purge VSV, canister, refueling valve, canister pump module, and ECM.
The ORVR (Onboard Refueling Vapor Recovery) function is provided in the refueling valve.
The canister pressure sensor has been included to the canister pump module.
The canister filter has been provided on the fresh air line. This canister filter is maintenance-free.
The followings are the typical conditions for enabling an EVAP leak check:
Typical Enabling
Condition
Five hours have elapsed after the engine has been turned OFF*.
Altitude: Below 2400 m (8000 feet)
Battery voltage: 10.5 V or more
Ignition switch: OFF
Engine coolant temperature: 4.4 to 35C (40 to 95F)
Intake air temperature: 4.4 to 35C (40 to 95F)
*: If engine coolant temperature does not drop below 35C (95F), this time should be extended to 7hours.
Even after that, if the temperature is not less than 35
C (95F), the time should be extended to 9.5 hours.

ENGINE - 2AZ-FE ENGINE
00REG22Y
To Intake Manifold
Purge VSV
Purge Air
Line
ECMFuel Tank
Canister Filter
Fresh Air LineRefueling Valve
Canister Pump Module
Ve n t
Va l v e
Leak Detection Pump
& Pump Motor
Canister
Pressure SensorCanisterP M
EG-55
System Diagram
Function of Main Components
ComponentFunction
CanisterContains activated charcoal to absorb the vapor gas that is created in the
fuel tank.
Refueling
Controls the flow rate of the vapor gas from the fuel tank to the canister
when the system is purging or during refueling.
Refueling
Va l v eRestrictor PassagePrevents a large amount of vacuum during purge operation or system
monitoring operation from affecting the pressure in the fuel tank.
Fresh Air LineFresh air goes into the canister and the cleaned drain air goes out into
the atmosphere.
Vent ValveOpens and closes the fresh air line in accordance with the signals from
the ECM.
Canister
Pump ModuleLeak Detection
PumpApplies vacuum pressure to the EVAP control system in accordance
with the signals from the ECM.
p
Canister
Pressure SensorDetects the pressure in the EVAP control system and sends the signals
to the ECM.
Purge VSV
Opens in accordance with the signals from the ECM when the system
is purging, in order to send the vapor gas that was absorbed by the
canister into the intake manifold. In system monitoring mode, this valve
controls the introduction of the vacuum into the fuel tank.
Canister FilterPrevents dust and debris in the fresh air from entering the system.
ECM
Controls the canister pump module and purge VSV in accordance with
the signals from various sensors, in order to achieve a purge volume that
suits the driving conditions. In addition, the ECM monitors the system
for any leakage and outputs a DTC if a malfunction is found.

ENGINE - 2AZ-FE ENGINE
D13N07 285EG76
Chamber A
Fresh Air Line
Refueling
Valve (Open)
Chamber B
From Fuel
Ta n k
Internal PressureCanister
To F u e l
Ta n k
Positive Pressure
(Fuel Tank Pressure)
Restrictor PassageNegative Pressure
(Intake Manifold Pressure)
During Refueling During Purge Operation or
System Monitoring Operation
228TU119
Fuel Tank Cap
Fresh Air
Fuel Inlet PipeTo Canister
Cleaned Drain Air EG-56
Construction and Operation
1) Refueling Valve
The refueling valve consists of the chamber A, chamber B, and restrictor passage. A constant
atmospheric pressure is applied to the chamber A.
During refueling, the internal pressure of the fuel tank increases. This pressure causes the refueling
valve to lift up, allowing the vapor gas to enter the canister.
The restrictor passage prevents the large amount of vacuum that is created during purge operation or
system monitoring operation from entering the fuel tank, and limits the flow of the vapor gas from the
fuel tank to the canister. If a large volume of vapor gas recirculates into the intake manifold, it will
affect the air-fuel ratio control of the engine. Therefore, the role of the restrictor passage is to help
prevent this from occurring.
2) Fuel Inlet (Fresh Air Line)
In accordance with the change of structure of the EVAP control system, the location of a fresh air line
inlet has been changed from the air cleaner section to the near fuel inlet. The flesh air from the atmosphere
and drain air cleaned by the canister will go in and out of the system through the passage shown below.

ENGINE - 2AZ-FE ENGINE
279EG26
D13N17 279EG25
Fresh Air
Canister
Pressure SensorLeak Detection Pump
Pump Motor
Vane PumpCanister
Pressure SensorVe n t Va l v e
Fresh Air
Canister
Canister Pump Module
Fresh AirVent Valve
Filter Filter
M
Leak Detection Pump
& Pump Motor
Canister
Pressure SensorP
Reference Orifice
[0.5 mm (0.02 in.) Diameter]Filter
To Canister
EG-57
3) Canister Pump Module
Canister pump module consists of the vent valve, leak detection pump, and canister pressure sensor.
The vent valve switches the passages in accordance with the signals received from the ECM.
A DC type brushless motor is used for the pump motor.
A vane type vacuum pump is used.
Simple Diagram

ENGINE - 2AZ-FE ENGINE
00REG23Y
To Intake Manifold
Atmosphere
Purge VSV
(Open)
ECM
00REG24Y
CloseOpen EG-58
System Operation
1) Purge Flow Control
When the engine has satisfied the predetermined conditions (closed loop, engine coolant temperature
above 74
C (165F), etc.), the stored vapor gas are purged from the canister whenever the purge VSV
is opened by the ECM.
The ECM will change the duty ratio cycle of the purge VSV, thus controlling purge flow volume. Purge
flow volume is determined by intake manifold pressure and the duty ratio cycle of the purge VSV.
Atmospheric pressure is allowed into the canister to ensure that purge flow is constantly maintained
whenever purge vacuum is applied to the canister.
2) ORVR (On-board Refueling Vapor Recovery)
When the internal pressure of the fuel tank increases during refueling, this pressure causes the diaphragm
in the refueling valve to lift up, allowing the vapor gas to enter the canister. Because the vent valve is
always open (even when the engine is stopped) when the system is in a mode other than the monitoring
mode, the air that has been cleaned through the canister is discharged outside the vehicle via the fresh
air line. If the vehicle is refueled in the monitoring mode, the ECM will recognize the refueling by way
of the canister pressure sensor, which detects the sudden pressure increase in the fuel tank, and will open
the vent valve.

ENGINE - 2AZ-FE ENGINE
275TU47
Purge
VSV
Ve n t
Va l v e
Pump Motor
System
PressureON (Open)
OFF (Close)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak Pressure
1) 2) 3) 4) 5) 6)EG-59
3) EVAP Leak Check
a. General
The EVAP leak check operates in accordance with the following timing chart:
Timing Chart
OrderOperationDescriptionTime
1)Atmospheric Pressure
MeasurementECM turns vent valve OFF (vent) and measures EVAP
control system pressure to memorize atmospheric pressure.10 sec.
2)0.02 in. Leak
Pressure MeasurementLeak detection pump creates negative pressure (vacuum)
through 0.02 in. orifice and the pressure is measured. ECM
determines this as 0.02 in. leak pressure.
60 sec.
3)EVAP Leak Check
Leak detection pump creates negative pressure (vacuum) in
EVAP control system and EVAP control system pressure is
measured. If stabilized pressure is larger than 0.02 in. leak
pressure, ECM determines EVAP control system has a
leakage.
If EVAP control system pressure does not stabilize within 12
minutes, ECM cancels EVAP monitor.
Within
12 min.
4)Purge VSV Monitor
ECM opens purge VSV and measures EVAP control system
pressure increase. If increase is large, ECM interprets this as
normal.
10 sec.
5)Repeat 0.02 in. Leak
Pressure MeasurementLeak detection pump creates negative pressure (vacuum)
through 0.02 in. orifice and pressure is measured. ECM
determines this as 0.02 in. leak pressure.
60 sec.
6)Final CheckECM measures atmospheric pressure and records monitor
result.—

ENGINE - 2AZ-FE ENGINE
00REG25Y
D13N22
Atmosphere
Purge VSV
(OFF)
ECMCanister Pump Module
Ve n t Va l v e
(OFF)
Leak Detection Pump
& Pump Motor
Canister
Pressure Sensor
Purge VSV
Vent Valve
Pump Motor
System PressureON (Open)
OFF (Close)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak Pressure
Atmospheric Pressure Measurement
P
M
EG-60
b. Atmospheric Pressure Measurement
1) When the ignition switch is turned OFF, the purge VSV and vent valve are turned OFF. Therefore,
the atmospheric pressure is introduced into the canister.
2) The ECM measures the atmospheric pressure through the signals provided by the canister pressure
sensor.
3) If the measurement value is out of standards, the ECM actuates the leak detection pump in order
to monitor the changes in the pressure.

ENGINE - 2AZ-FE ENGINE
00REG26Y
275TU48
Atmosphere
Purge VSV
(OFF)
ECMCanister Pump Module
Ve n t Va l v e
(OFF)
Leak Detection Pump
& Pump Motor
Canister Pressure
Sensor
Reference Orifice
Purge VSV
Vent Valve
Pump Motor
System PressureON (Open)
OFF (Close)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak Pressure
0.02 in. Leak Pressure Measurement
M
P
EG-61
c. 0.02 in. Leak Pressure Measurement
1) The vent valve remains OFF, and the ECM introduces atmospheric pressure into the canister and
actuates the leak detection pump in order to create a negative pressure.
2) At this time, the pressure will not decrease beyond a 0.02 in. leak pressure due to the atmospheric
pressure that enters through a 0.02 in. diameter reference orifice.
3) The ECM compares the logic value with this pressure, and stores it as a 0.02 in. leak pressure in its
memory.
4) If the measurement value is below the standard, the ECM will determine that the reference orifice
is clogged and store DTC (Diagnostic Trouble Code) P043E in its memory.
5) If the measurement value is above the standard, the ECM will determine that a high flow rate pressure
is passing through the reference orifice and store DTCs (Diagnostic Trouble Codes) P043F, P2401
and P2402 in its memory.

ENGINE - 2AZ-FE ENGINE
00REG27Y
275TU49
Purge VSV
(OFF)Atmosphere
ECMCanister Pump Module
Vent Valve
(ON)
Leak Detection Pump
& Pump Motor
Canister
Pressure Sensor
M
P
Reference Orifice
Va c u u m
Purge VSV
Ve n t Va l v e
Pump Motor
System PressureOFF (Close)
ON (Open)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak Pressure
EVAP Leak CheckP0455
P0456
Normal EG-62
d. EVAP Leak Check
1) While actuating the leak detection pump, the ECM turns ON the vent valve in order to introduce a
vacuum into the canister.
2) When the pressure in the system stabilizes, the ECM compares this pressure with the 0.02 in. leak
pressure in order to check for a leakage.
3) If the measurement value is below the 0.02 in. leak pressure, the ECM determines that there is no
leakage.
4) If the measurement value is above the 0.02 in. leak pressure and near atmospheric pressure, the ECM
determines that there is a gross leakage (large hole) and stores DTC P0455 in its memory.
5) If the measurement value is above the 0.02 in. leak pressure, the ECM determines that there is a small
leakage and stores DTC P0456 in its memory.

ENGINE - 2AZ-FE ENGINE
00REG28Y
275TU50 M
P
Atmosphere
Atmosphere
Purge VSV
(ON)
ECMCanister Pump Module
Vent Valve
(ON)
Leak Detection Pump
& Pump Motor
Canister
Pressure Sensor
Purge VSV Monitor
P0441
Normal
Purge VSV
Vent Valve
Pump Motor
System PressureON (Open)
OFF (Close)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak PressureEG-63
e. Purge VSV Monitor
1) After completing an EVAP leak check, the ECM turns ON (open) the purge VSV with the leak
detection pump actuated, and introduces the atmospheric pressure from the intake manifold to the
canister.
2) If the pressure change at this time is within the normal range, the ECM determines the condition to
be normal.
3) If the pressure is out of the normal range, the ECM will stop the purge VSV monitor and store DTC
P0441 in its memory.