cooling system TOYOTA RAV4 2006 Service Repair Manual

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 - 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
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

ENGINE - 2GR-FE ENGINEEG-101
ENGINE CONTROL SYSTEM
1. General
The engine control system of the 2GR-FE engine has the following features.
System
Outline
SFI
(Sequential Multiport
Fuel Injection)
[See page EG-117]
An L-type SFI system detects the intake air mass with a hot-wire type air
flow meter.
ESA
(Electronic Spark
Advance)
Ignition timing is determined by the ECM based on signals from various
sensors. The ECM corrects ignition timing in response to engine
knocking.
This system selects the optimal ignition timing in accordance with the
signals received from the sensors and sends the (IGT) ignition signal to
the igniter.
ETCS-i
(Electronic Throttle
Control
System-intelligent)
[See page EG-118]
Optimally controls the throttle valve opening in accordance with the amount
of accelerator pedal effort and the condition of the engine and the vehicle.
Dual VVT-i
(Variable Valve
Timing-intelligent)
System
[See page EG-120]
Controls the intake and exhaust camshafts to an optimal valve timing in
accordance with the engine condition.
ACIS
(Acoustic Control
Induction System)
[See page EG-126]The intake air passages are switched according to the engine speed and
throttle valve opening angle to provided high performance in all speed
ranges.
Air Intake Control
System
[See page EG-128]The intake air duct is divided into two areas, and the ECM controls the air
intake control valve and the actuator that are provided in one of the areas to
reduce the amount of engine noise.
Fuel Pump Control
[See page EG-53 in
2AZ-FE section]Fuel pump operation is controlled by signals from the ECM.
The fuel pump is stopped, when the SRS airbag is deployed in a frontal,
side, and rear side collision.
Air Conditioning Cut-off
ControlBy turning the air conditioning compressor ON or OFF in accordance with
the engine condition, drivability is maintained.
Charging Control
[See page EG-65 in
2AZ-FE section]The engine ECU regulates the charging voltage of the generator in
accordance with the driving conditions and the charging state of the battery.
Cooling Fan Control
[See page EG-129]
The cooling fan ECU steplessly controls the speed of the fans in accordance
with the engine coolant temperature, vehicle speed, engine speed, and air
conditioning operating conditions. As a result, the cooling performance is
improved.
(Continued)

ENGINE - 2GR-FE ENGINE
01MEG29Y
Ignition SwitchCombination Meter
Vehicle Speed Signal
MIL
Battery Current Sensor
(Built-in Battery
Temperature Sensor)
Park / Neutral
Position Switch
Battery
Generator
Fuel Pump Relay
Fuel Pump
Vent Valve
Circuit Opening
RelayDLC3*1*2*3
CAN
ECM
Cruise Control Switch
Accelerator Pedal
Position Sensor
Stop Light Switch
Canister
Pressure
SensorLeak
Detection
Pump
Intake Air
Temp. Sensor
VSV (For
Air Intake
Control)Mass Air
Flow Meter
AirThrottle Position
Sensor
Purge VSV
Throttle
Control
Motor
*4*5
Fan
Motor No. 1Fan
Motor
No. 2
Cooling
Fan
ECUCooling
Fan
ECU
No. 1Cooling
Fan
ECU
No. 2
Fan Motor No. 1
Fan Motor No. 2
ACIS Actuator
Intake Camshaft Timing
Oil Control Valve (Bank 2)Injector Injector
Intake Camshaft Timing
Oil Control Valve (Bank 1)
Intake VVT Sensor (Bank 1)
Ignition Coil With Igniter
Exhaust VVT Sensor (Bank 1)
Exhaust Camshaft Timing
Oil Control Valve (Bank 1)
Air-fuel Ratio Sensor
(Bank1, Sensor1)
TWC
Knock
Sensor
Intake VVT
Sensor (Bank 2)
Exhaust VVT
Sensor (Bank 2)
Air-fuel Ratio Sensor
(Bank2, Sensor1)Exhaust Camshaft
Timing Oil Control
Valve (Bank 2)
Crankshaft Position
Sensor
Engine Coolant
Temperature Sensor Heated Oxygen Sensor
(Bank1, Sensor2)Heated Oxygen Sensor
(Bank2, Sensor2)TWCTWC
EG-106
3. Engine Control System Diagram
*1: Air Conditioning ECU
*
2: Airbag Sensor Assembly
*
3: Skid Control ECU
*
4: Except Towing Package Models
*
5: Towing Package Models

ENGINE - 2GR-FE ENGINE
01MEG21Y
01MEG22Y
Engine Coolant Temperature
Sensor
Crankshaft Position Sensor
Combination Meter
Vehicle Speed SignalECM
CAN
Air Conditioning ECUCooling
Fan
ECUFan Motor
No. 1
Fan Motor
No. 2
Except Towing Package Models
Towing Package Models Engine Coolant Temperature
Sensor
Crankshaft Position Sensor
Combination Meter
Vehicle Speed SignalECM
CAN
Air Conditioning ECUCooling
Fan
ECU
No. 1
Cooling
Fan
ECU
No. 2Fan Motor
No. 1
Fan Motor
No. 2EG-129
12. Cooling Fan Control System
General
A cooling fan control system is used. To achieve an optimal fan speed in accordance with the engine coolant
temperature, vehicle speed, engine speed, and air conditioning operating conditions, the ECM calculates
the proper fan speed and sends the signals to the front controller. By receiving the signals from the ECM,
the front controller sends proper fan speed control signals to the cooling fan ECU.
Upon receiving the signals from the front controller, the cooling fan ECU actuates the fan motors.
Wiring Diagram

CO–42AZ-FE COOLING – COOLING FAN SYSTEM
CO
ON-VEHICLE INSPECTION
HINT:
It is normal for the cooling fan to sometimes rotate when the
ignition switch is turned from ACC to ON.
1. CHECK COOLING FAN OPERATION AT LOW
TEMPERATURES (Below 94
C (201F))
(a) Turn the ignition switch ON with the A/C switch OFF.
(b) Check that the cooling fan stops.
If it does not, check the cooling fan relays and
engine coolant temperature sensor, and then check
for disconnection of the connector or a wire break
between the cooling fan relay and engine coolant
temperature sensor.
(c) Disconnect the engine coolant temperature sensor
connector.
(d) Check that the cooling fan rotates.
If it does not, check the fuses, cooling fan relays,
ECM and cooling fan, and then check for an open
circuit between the cooling fan relay and engine
coolant temperature sensor.
(e) Reconnect the engine coolant temperature sensor
connector.
2. CHECK COOLING FAN OPERATION AT HIGH
TEMPERATURES (Above 96
C (205F))
(a) Start the engine, and then raise the coolant
temperature to above 96
C (205F).
HINT:
Coolant temperature is the value detected by the
engine coolant temperature sensor on the cylinder
head.
(b) Check that the A/C switch is OFF.
A127842
A112176
A127843