Page 1 of 2000

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.
Page 9 of 2000
ENGINE - 2AZ-FE ENGINE
240EG46 181EG10
VVT-i ControllerIntake CamshaftExhaust
Camshaft
Chain
Te n s i o n e r
Chain Damper
Chain SlipperCamshaft
Va l v e
Lifter
Service Tip
The adjustment of the valve clearance is accomplished by selecting and replacing the appropriate
valve lifters.
A total of 35 valve lifters are available in 0.02 mm (0.008 in.) increments, from 5.06 mm (0.199 in.)
to 5.74 mm (0.226 in.). For details, refer to 2006 RAV4 Repair Manual (Pub. No. RM01M1U).
EG-12
VA LV E M E C H A N I S M
1. General
The VVT-i system is used to improve fuel economy, engine performance and reduce exhaust emissions.
For details of VVT-i system, see page EG-48.
The intake and exhaust camshafts are driven by a timing chain.
Along with the increase in the amount of valve lift, the shim-less type valve lifter is used. This valve lifter
increases the cam contact surface.
Page 10 of 2000

ENGINE - 2AZ-FE ENGINE
181EG11
VVT-i ControllerIntake CamshaftTiming Rotor
Exhaust Camshaft
Timing Sprocket
185EG25 181EG14
Cam Spring
Cam
Plunger
SpringChain
Te n s i o n e r
Chain Damper
Oil Jet
Chain TensionerChain SlipperEG-13
2. Camshaft
The intake camshaft is provided with timing rotor to trigger the camshaft position sensor.
In conjunction with the adoption of the VVT-i system, an oil passage is provided in the intake camshaft
in order to supply engine oil pressure to the VVT-i system.
A VVT-i controller has been installed on the front of the intake camshaft to vary the timing of the intake
valves.
3. Timing Chain
A roller chain with an 8 mm (0.315 in.) pitch is used to make the engine more compact.
The timing chain is lubricated by an oil jet.
The chain tensioner uses a spring and oil pressure to maintain proper chain tension at all times.
The chain tensioner suppresses noise generated by the timing chain.
A ratchet type non-return mechanism is used.
To achieve excellent serviceability, the chain tensioner is constructed so that it can be removed and
installed from the outside of the timing chain cover.
Page 11 of 2000
ENGINE - 2AZ-FE ENGINE
208EG07
VVT-i Controller
Camshaft Timing
Oil Control Valve
Oil Return
Hole
Oil PumpOil Filter Chain
Te n s i o n e r
01NEG33Y
Bypass
Va l v e
Relief
Va l v eMain Oil Hole
Oil Filter
Oil Pump
Oil StrainerChain
Te n s i o n e rCylinder Head
Exhaust
Camshaft
Journal
Oil Control
Va l v e
VVT-i Controller
Oil Pan
Intake
Camshaft
Journal
Crankshaft
Journal
Crankshaft
Pin
Oil Jet
Piston
Cylinder
Block
Barance
Shaft
Timing
Chain EG-14
LUBRICATION SYSTEM
1. General
The lubrication circuit is fully pressurized and oil passes through an oil filter.
The trochoid gear type oil pump is chain-driven by the crankshaft.
The oil filter is attached downward from the crankcase to improve serviceability.
Along with the adoption of the VVT-i system, the cylinder head is provided with a VVT-i controller and
a camshaft timing oil control valve. This system is operated by the engine oil.
Oil Circuit
Page 16 of 2000
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.
Page 19 of 2000
ENGINE - 2AZ-FE ENGINE
01MEG30Y
Fuel Pump Assembly
Fuel Filter
Pressure Regulator
Quick Connector
Injector
Fuel Tank
Canister EG-22
FUEL SYSTEM
1. General
The fuel returnless system is used to reduce evaporative emissions.
A fuel cut control is used to stop the fuel pump when the SRS airbag is deployed in a front or side collision.
For details, see page EG-53.
A quick connector is used in the fuel main pipe to improve serviceability.
The 12-hole type fuel injector is used.
The ORVR (On-board Refueling Vapor Recovery) system is used. For details, see page EG-54.
Page 37 of 2000

ENGINE - 2AZ-FE ENGINE
214CE08
Steel Weight
Inertia
Piezoelectric
Element
214CE06
Knock Sensor
200 k
Piezoelectric
ElementOpen / Short Circuit
Detection ResistorKNK1
EKNKECM
5 V
200 k
IC
Service Tip
In accordance with the adoption of an open / short circuit detection resistor, the inspection
method for the sensor has been changed. For details, refer to the 2006 RAV4 Repair Manual
(Pub. No. RM01M1U).
To prevent the water accumulation in the connecter, make sure to install the flat type knock
sensor in the position as shown in the following illustration.
251EG12
10
10
Knock Sensor EG-40
3) Operation
The knocking vibration is transmitted to the
steel weight and its inertia applies pressure to
the piezoelectric element. The action
generates electromotive force.
4) Open / Short Circuit Detection Resistor
While the ignition is ON, the open / short circuit detection resistor in the knock sensor and the resistor
in the ECM keep constant the voltage at the terminal KNK1 of engine.
An IC (Integrated Circuit) in the ECM is always monitoring the voltage of the terminal KNK1. If the
open / short circuit occurs between the knock sensor and the ECM, the voltage of the terminal KNK1 will
change and the ECM detects the open / short circuit and stores DTC (Diagnostic Trouble Code).
Page 38 of 2000
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.