2006 TOYOTA RAV4 valve body

ENGINE - 2AZ-FE ENGINE EG-4
FEATURES OF 2AZ-FE ENGINE
The 2AZ-FE engine has achieved the following performance through the use of the items listed below.
(1) High performance and reliability
(2) Low noise and vibration
(3) Lightweight and compact design
(4) Good serviceability
(5) Clean emission and fuel economy
Section
Item(1)(2)(3)(4)(5)
Engine
A cylinder block made of aluminum alloy along with a
magnesium alloy die-cast cylinder head cover is used.
Engine
ProperA taper squish shape is used for the combustion chamber.p
A resin gear balance shaft is used.
Vl
A timing chain and chain tensioner are used.
Va l v e
MechanismThe shim-less type valve lifters are used.MechanismThe VVT-i system is used.
A chacoal filter is used in the air cleaner cap.
Intake andIntake manifold made of plastic is used.Intake and
ExhaustThe linkless-type throttle body is used.
SystemA thin-wall ceramic TWC (Three-Way Catalytic converter)
is used.
The fuel returnless system is used.
Fuel
System
Quick connectors are used to connect the fuel hose with the
fuel pipe.
System12-hole type fuel injectors with high atomizing performance
are used.
Ignition
SystemIridium-tipped spark plugs are used.
Charging
SystemThe segment conductor type generator is used.
Starting
SystemPS (Planetary reduction-Segment conductor motor) type
starter is used.
The ETCS-i is used.
Engine
Control
The DIS (Direct Ignition System) makes ignition timing
adjustment unnecessary.
Control
SystemThe non-contact type sensor is used in the throttle position
sensor.
The planar type air-fuel ratio sensor is used.

ENGINE - 2AZ-FE ENGINE
01NEG35Y
Throttle Body
To H e a t e r C o r e
To R a d i a t o r
Thermostat
From Radiator Wa t e r P u m pBypass Passage
01NEG59Y
Bypass PassageCylinder Head
Wa t e r P u m p
Cylinder Block
Thermostat
Reservoir
Ta n k
RadiatorThrottle
BodyHeater Core EG-16
COOLING SYSTEM
The cooling system uses a pressurized forced-circulation system with pressurized reservoir tank.
A thermostat with a bypass valve is located on the water inlet housing to maintain suitable temperature
distribution in the cooling system.
An aluminum radiator core is used for weight reduction.
The flow of the engine coolant makes a U-turn in the cylinder block to ensure a smooth flow of the engine
coolant. In addition, a bypass passage is enclosed in the cylinder head and the cylinder block.
Warm water from the engine is sent to the throttle body to prevent freeze-up.
The TOYOTA genuine Super Long Life Coolant (SLLC) is used.
System Diagram

ENGINE - 2AZ-FE ENGINE
01MEG10Y
Charcoal FilterAir Cleaner Cap
Air Cleaner Element
(Nonwoven Fabric)
Service Tip
The charcoal filter, which is maintenance-free, cannot be removed from the air cleaner cap.
01NEG42Y
Throttle Position
Sensor
Throttle Control MotorEG-19
2. Air Cleaner
A nonwoven, full-fabric type air cleaner element is used.
A charcoal filter, which adsorbs the HC that accumulates in the intake system when the engine is stopped,
is used in the air cleaner cap in order to reduce evaporative emissions.
3. Throttle Body
The linkless-type throttle body is used and it realizes excellent throttle control.
A DC motor with excellent response and minimal power consumption is used for the throttle control motor.
The ECM performs the duty ratio control of the direction and the amperage of the current that flows to
the throttle control motor in order to regulate the opening angle of the throttle valve.

ENGINE - 2AZ-FE ENGINE
01NEG43Y
238EG79
230LX12
Throttle Body
Throttle Position
Sensor Portion
Throttle Control
MotorMagnetic
Yo k e
Hall IC
Cross Section
Throttle Position
Sensor
Magnetic Yoke
Hall
IC
Hall
IC
VTA1
ETA
VCTA
VTA2ECMOutput
Voltage(V)
5
0
Fully Close10 90 (
)
Fully Open VTA2
VTA1
Throttle Valve Opening Angle
Service Tip
The inspection method differs from the conventional contact type throttle position sensor because
this non-contact type sensor uses a Hall IC.
For details, refer to the 2006 RAV4 Repair Manual (Pub. No. RM01M1U).
EG-41
Throttle Position Sensor
The throttle position sensor is mounted on the throttle body to detect the opening angle of the throttle valve.
The throttle position sensor converts the magnetic flux density that changes when the magnetic yoke
(located on the same axis as the throttle shaft) rotates around the Hall IC into electric signals to operate the
throttle control motor.

ENGINE - 2AZ-FE ENGINE
00REG17Y
Accelerator Pedal
Position SensorThrottle Valve
Throttle Position SensorThrottle
Control
Motor
Mass Air
Flow MeterECMSkid
Control
ECU
Ignition
CoilFuel
Injector
: CANEG-43
6. ETCS-i (Electronic Throttle Control System-intelligent)
General
The ETCS-i is used, providing excellent throttle control in all the operating ranges. In the 2AZ-FE
engine, the accelerator cable has been discontinued, and an accelerator pedal position sensor has been
provided on the accelerator pedal.
In the conventional throttle body, the throttle valve opening is determined by the amount of the
accelerator pedal effort. In contrast, the ETCS-i uses the ECM to calculate the optimal throttle valve
opening that is appropriate for the respective driving condition and uses a throttle control motor to control
the opening.
The ETCS-i controls the IAC (Idle Air Control) system, the TRAC (Traction Control), VSC (Vehicle
Stability Control) system and curise control system.
In case of an abnormal condition, this system switches to the limp mode.
System Diagram

ENGINE - 2AZ-FE ENGINE
Throttle Body
Throttle Position
Sensor Portion
Reduction
Gears
Throttle ValveMagnetic Yoke
Hall IC
Throttle Control
Motor A
View from A
Cross Section
01NEG44Y
EG-44
Construction
1) Throttle Position Sensor
The throttle position sensor is mounted on the throttle body, to detect the opening angle of the throttle
valve.
2) Throttle Control Motor
A DC motor with excellent response and minimal power consumption is used for the throttle control
motor. The ECM performs the duty ratio control of the direction and the amperage of the current that
flows to the throttle control motor in order to regulate the opening of the throttle valve.
Operation
1) General
The ECM drives the throttle control motor by determining the target throttle valve opening in accordance
with the respective operating condition.
Non-linear Control
Idle Air Control
TRAC Throttle Control
VSC Coordination Control
Cruise Control

ENGINE - 2AZ-FE ENGINE
199EG45
ECM
Accelerator Pedal
Position Sensor
Main
Sub
Main
Sub
Throttle
Position
Sensor
Open
Throttle ValveReturn
SpringThrottle
Control
Motor
Accelerator Pedal Throttle Body
199EG46
Accelerator Pedal Throttle BodyECM
Accelerator Pedal
Position Sensor
Main
Sub
Close by
Return Spring
Main
Sub
Throttle
Position
SensorThrottle ValveReturn
SpringThrottle
Control
Motor EG-46
Fail-safe of Accelerator Pedal Position Sensor
The accelerator pedal position sensor is comprised of two (main, sub) sensor circuits. If a malfunction
occurs in either one of the sensor circuits, the ECM detects the abnormal signal voltage difference
between these two sensor circuits and switches to the limp mode. In the limp mode, the remaining circuit
is used to calculate the accelerator pedal depressed angle, in order to operate the vehicle under the limp
mode control.
If both circuits have malfunctions, the ECM detects the abnormal signal voltage from these two sensor
circuits and stops the throttle control. At this time, the vehicle can be driven within its idling range.

ENGINE - 2AZ-FE ENGINE
199EG47
Injectors
ECMIgnition Coils
Accelerator Pedal
Position Sensor
Main
Sub
Main
Sub
Return to
Prescribed Angle
Throttle ValveReturn
SpringThrottle
Control
Motor
Accelerator Pedal Throttle BodyEG-47
Fail-safe of Throttle Position Sensor
The throttle position sensor is comprised of two (main, sub) sensor circuits. If a malfunction occurs in
either one or both of the sensor circuits, the ECM detects the abnormal signal voltage difference between
these two sensor circuits, cuts off the current to the throttle control motor, and switches to the limp mode.
Then, the force of the return spring causes the throttle valve to return and stay at the prescribed opening
angle. At this time, the vehicle can be driven in the limp mode while the engine output is regulated
through the control of the fuel injection (intermittent fuel-cut) and ignition timing in accordance with the
accelerator opening.
The same control as above is effected if the ECM detects a malfunction in the throttle control motor
system.