cooling TOYOTA RAV4 2006 Service Repair Manual

ENGINE - 2AZ-FE ENGINE
208EG67 DR011EG21
Exhaust Side
Intake Side A A
A - A Cross Section Injector
IN
EX
Bypass
Passage
Ta p e r S q u i s h EG-6
3. Cylinder Head
Through the adoption of the taper squish combustion chamber, the engine knocking resistance and fuel
efficiency have been improved.
An upright intake port is used to improve the intake efficiency.
Installing the injectors in the cylinder head enables the injectors inject fuel as close as possible to the
combustion chamber. This prevents the fuel from adhering to the intake port walls, which reduces HC
exhaust emissions.
The routing of the water jacket in the cylinder head has been optimized to realize the high cooling
performance. In addition, a water bypass passage has been provided below the exhaust ports to reduce the
number of parts and the weight.

ENGINE - 2AZ-FE ENGINE
01NEG34Y
Oil Jets
Check
Va l v e
Oil
Bottom Side View Oil Jet Cross SectionEG-15
Oil Capacity
Liters (US qts, Imp. qts)
Dry
5.0 (5.3, 4.4)
with Oil Filter4.3 (4.5, 3.8)
without Oil Filter4.1 (3.8, 3.1)
2. Oil Jet
Piston oil jets for cooling and lubricating the pistons are used in the cylinder block.
These oil jets contain a check valve to prevent oil from being fed when the oil pressure is low. This prevents
the overall oil pressure in the engine from dropping.

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 EG-30
ENGINE CONTROL SYSTEM
1. General
The engine control system for the 2AZ-FE engine has the following systems.
System
Outline
SFI
Sequential Multiport
Fuel InjectionAn L-type SFI system directly detects the intake air volume with a hot-wire
type mass air flow meter.
The fuel injection system is a sequential multiport fuel injection system.
ESA
Electronic Spark
AdvanceIgnition timing is determined by the ECM based on signals from various sensors.
The ECM corrects ignition timing in response to engine knocking.
ETCS-i
Electronic
Optimally controls the throttle valve opening in accordance with the amount of
accelerator pedal effort and the condition of the engine and the vehicle.
Electronic
Throttle Control
System-intelligent
(See page-43)A linkless-type is used, without an accelerator cable.
An accelerator pedal position sensor is provided on the accelerator pedal.
A non-contact type throttle position sensor and accelerator pedal position
sensor are used.
VVT-i
Va r i a b l e Va l v e
Timing-intelligent
(See page EG-48)
Controls the intake camshaft to an optimal valve timing in accordance with the
engine condition.
Air-fuel Ratio
Sensor, Oxygen
Sensor Heater
ControlMaintains the temperature of the air-fuel ratio sensor or oxygen sensor at an
appropriate level to realize accuracy of detection of the oxygen concentration in
the exhaust gas.
Air Conditioning
Cut-off ControlBy turning the air conditioning compressor ON or OFF in accordance with the
engine condition, drivability is maintained.
Cooling Fan Control
(See page EG-52)Radiator cooling fan operation is controlled by signals from ECM based on the
engine coolant temperature sensor signal and the condition of the air
conditioning operation.
Fuel Pump Control
(See page EG-53)Fuel pump operation is controlled by signal from the ECM.
The fuel pump is stopped when the SRS driver’s and front passenger’s airbags
are deployed.
Evapotative Emission
The ECM controls the purge flow of evaporative emissions (HC) in the canister
in accordance with engine conditions.
Evapotative Emission
Control
(See page EG-54)Approximately five hours after the ignition switch has been turned OFF, the
ECM operates the canister pump module to detect any evaporative emission
leakage occurring in the EVAP (evaporative emission) control system through
changes in the 0.02 in. leak pressure.
Charging Control
(See page EG-65)The ECM regulates the charging voltage of the generator in accordance with the
driving conditions and the charging state of the battery.
(Continued)

ENGINE - 2AZ-FE ENGINE
01MEG05Y
DEFGGER SWITCH
TA I L L I G H T S W I T C H
STOP LIGHT SWITCH
CURRENT SENSOR
CANISTER PUMP MODULE
CANISTER PRESSURE
SENSOR
TRANSPONDER KEY ECU*
AIRBAG SENSOR ASSEMBLY
EPS ECU
AIR CONDITIONING ECU
SKID CONTROL ECU
DLC3
BATTERYELS1
ELS3
STP
ST1-
THB
VCIB
PPMP
IMI
IMO
CANH,
CANL
TC
TA C H
BATTECMFA N H
FA N L
MPMP
VPMP
PRG
RLO
DF
MREL
+B
WCOOLING FAN CONTROL
COOLING FAN RELAY No.1
COOLING FAN RELAY No.2
COOLING FAN RELAY No.3
EVAPORATIVE EMISSION
CONTROL
CANISTER PUMP MODULE
LEAK DETECTION PUMP
VENT VALVE
GENERATOR
MAIN RELAY
COMBINATION METER
MIL
PURGE VSV
: CANEG-33
*: Models with Engine Immobilizer System

ENGINE - 2AZ-FE ENGINE
01NEG09Y
01NEG10Y
Air
Conditioning
ECU
Engine Coolant
Temperature SensorFANL
ECM
FA N HCooling Fan
Relay No.3
Cooling Fan
Motor No.2
Cooling Fan
Relay No.1
Cooling Fan
Motor No.1
Low Speed (Series Connection)
High Speed (Parallel Connection) Air
Conditioning
ECU
Engine Coolant
Temperature SensorFA N L
ECM
FA N HCooling Fan
Relay No.3
Cooling Fan
Motor No.2
Cooling Fan
Relay No.1
Cooling Fan
Relay No.2
Cooling Fan
Motor No.1 : CAN
Cooling Fan
Relay No.2
EG-52
8. Cooling Fan Control
On the models with air conditioning, the ECM controls the operation of the cooling fan in two speeds (Low
and High) based on the engine coolant temperature sensor signal and the air conditioning ECU signal. This
control is accomplished by operating the 2 fan motors in 2 stages through low speed (series connection) and
high speed (parallel connection).
Wiring Diagram
Cooling Fan Operation
Air Conditioning ConditionEngine Coolant Temperature C (F)
A / C CompressorRefrigerant Pressure94 (201.2) or lower95.5 (203.9) or higher
OFF1.2 MPa (12.5 kgf / cm2, 178 psi) or lowerOFFHigh
ON1.2 MPa (12.5 kgf / cm2, 178 psi) or lowerLowHighON1.2 MPa (12.5 kgf / cm2, 178 psi) or higherHighHigh

ENGINE - 2GR-FE ENGINEEG-71
FEATURES OF 2GR-FE ENGINE
The 2GR-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
Item
(1)(2)(3)(4)(5)
A steel laminate type cylinder head gasket is used.
An upright intake port is used.
EngineA taper squish shape is used for combustion chamber.Engine
ProperA cylinder block made of aluminum alloy is used.Proper
The skirt portion of the piston is applied with resin to
reduce friction.
An oil pan No. 1 made of aluminum alloy is used.
The Dual VVT-i (Variable Valve Timing-intelligent)
system is used.
Va l v e
Mh i
Hydraulic lash adjusters are used.
MechanismTiming chains and chain tensioners are used.
Roller rocker arms are used.
Lubrication
SystemAn oil filter with a replaceable element is used.
Cooling SystemThe TOYOTA Genuine SLLC (Super Long Life Coolant)Cooling SystemThe TOYOTA Genuine SLLC (Super Long Life Coolant)
is used for the engine coolant.
The linkless-type throttle body is used.
Intake andThe intake air chamber made of plastic is used.Intake and
Exhaust
S
A stainless steel exhaust manifold is used.
SystemAn ultra thin-wall, high-cell density ceramic type TWC
(Three-Way Catalytic converter) is used.
The fuel delivery pipe made of plastic is used.
Fuel SystemA compact 12-hole type injector is used.Fuel SystemQuick connectors are used to connect the fuel hose with
the fuel pipe.
Ignition System
The DIS (Direct Ignition System) makes ignition timing
adjustment unnecessary.
Ignition System
The long-reach type spark plugs are used.
(Continued)

ENGINE - 2GR-FE ENGINE
285EG21
Timing Chain Cover
Wa t e r P u m p G a s k e t
Wa t e r P u m pWater Pump Swirl
Chamber
Oil Pump
Housing
Oil Pump RotorsTiming Chain
Cover
Oil Pump Chamber
View from Front Side View from Back Side
285EG22
Oil
Passage
Check Ball
Check Ball
Spring
Plunger SpringPlunger
Roller Rocker ArmCam
Oil
Passage
Hydraulic
Lash Adjuster
Service Tip
Valve clearance adjustment is not necessary because a hydraulic lash adjuster is used in this model.
EG-83
4. Timing Chain Cover
The timing chain cover has an integrated construction consisting of the cooling system (water pump and
water passage) and the lubrication system (oil pump and oil passage). Thus, the number of parts has been
reduced to reduce weight.
5. Hydraulic Lash Adjuster
The hydraulic lash adjuster, which is located at the fulcrum of the roller rocker arm, consists primarily of
a plunger, plunger spring, check ball, and check ball spring.
The engine oil that is supplied by the cylinder head and the built-in spring actuates the hydraulic lash
adjuster. The oil pressure and the spring force that act on the plunger push the roller rocker arm against
the cam, in order to adjust the valve clearance that is created during the opening and closing of the valve.
As a result, engine noise is reduced.

ENGINE - 2GR-FE ENGINE
285EG24
Timing Chain Cover
Oil Pump
Housing
Oil Pump Rotors
(Cycloid Rotor)Crankshaft
To Cylinder
Block
From Oil
Filter
To
Oil FilterFrom
Oil Strainer
Oil passage in the oil pump
285EG25
Oil Jet Cross Section
Oil JetsCheck
Va l v eEngine Oil EG-86
2. Oil Pump
A compact cycloid rotor type oil pump directly driven by the crankshaft is used.
This oil pump has used an internal relief method which circulates relief oil to the suction passage in the
oil pump. This aims to minimize oil level change in the oil pan, reduce friction, and reduce air mixing rate
in the oil.
3. Oil Jet
Oil jets for cooling and lubricating the pistons have been provided in the cylinder block, in the center of
the right and left banks.
These oil jets contain a check valve to prevent oil from being fed when the oil pressure is low. This prevents
the overall oil pressure in the engine from dropping.

ENGINE - 2GR-FE ENGINE
285EG27
Air Bleeder PlugTo Throttle Body
From Throttle Body
To H e a t e r
From Heater
To Radiator
From Radiator Thermostat
Opening Temperature:
80 - 84
C (176 - 183F)
01MEG35Y
ThermostatBypass Pipe
Heater Return Pipe
Air Bleeder Plug
Cylinder Head
Cylinder Block
Wa t e r P u m p
Radiator
Throttle
Body
Heater
Reservoir
Ta n k
EG-88
COOLING SYSTEM
1. General
The cooling system is a pressurized, forced-circulation type.
A thermostat with a bypass valve is located on the water inlet housing to maintain suitable temperature
distribution in the cooling system.
A cooling fan control system in which the ECM optimally controls cooling fan speed is used. For details,
see page EG-129.
An air bleeder plug is provided on the water inlet assembly to improve the efficiency of changing the
engine coolant. For details, refer to the 2006 RAV4 Repair Manual (Pub. No. RM01M1U).
The TOYOTA genuine SLLC (Super Long Life Coolant) is used for the engine coolant.
System Diagram