TOYOTA RAV4 2006 Service Service Manual

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
005EG13Y
: With Control
: Without Control
Vehicle’s
Longitudinal G
Throttle Valve
Opening Angle
Accelerator Pedal
Depressed Angle
0
0
0
Time
EG-45
2) Normal Throttle Control (Non-linear Control)
It controls the throttle to an optimal throttle valve opening that is appropriate for the driving condition
such as the amount of the accelerator pedal effort and the engine speed in order to realize excellent throttle
control and comfort in all operating ranges.
Control Examples During Acceleration and Deceleration
3) Idle Air Control
The ECM controls the throttle valve in order to constantly maintain an ideal idle speed.
4) TRAC Throttle Control
As part of the TRAC system, the throttle valve is closed by a demand signal from the skid control ECU
if an excessive amount of slippage is created at a driving wheel, thus facilitating the vehicle in providing
excellent stability and driving force.
5) VSC Coordination Control
In order to bring the effectiveness of the VSC system control into full play, the throttle valve opening
angle is controlled by effecting a coordination control with the skid control ECU.
6) Cruise Control
An ECM with an integrated cruise control ECU directly actuates the throttle valve for operation of the
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.

ENGINE - 2AZ-FE ENGINE
DR011EG25
Camshaft Position Sensor
Engine Coolant
Temperature Sensor
Crankshaft
Position Sensor
Camshaft Timing
Oil Control Valve
Throttle Position
Sensor
ECM
Mass Air Flow Meter Vehicle Speed Signal
221EG16
Crankshaft Position Sensor
Mass Air Flow Meter
Throttle Position Sensor
Engine Coolant Temp. Sensor
Camshaft Position Sensor
Vehicle Speed SignalECM
Target Valve Timing
Feedback
Correction
Actual Valve Timing
Duty-cycle
Control
Camshaft Timing
Oil Control Valve
EG-48
7. VVT-i (Variable Valve Timing-intelligent) System
General
The VVT-i system is designed to control the intake camshaft within a range of 40 (of Crankshaft Angle)
to provide valve timing that is optimally suited to the engine condition. This realizes proper torque in
all the speed ranges as well as realizing excellent fuel economy, and reducing exhaust emissions.
Using the engine speed signal, vehicle speed signal, and the signals from mass air flow meter, throttle
position sensor and engine coolant temperature sensor, the ECM can calculate optimal valve timing for
each driving condition and controls the camshaft timing oil control valve. In addition, the ECM uses
signals from the camshaft position sensor and crankshaft position sensor to detect the actual valve timing,
thus providing feedback control to achieve the target valve timing.

ENGINE - 2AZ-FE ENGINE
185EG48
185EG49
185EG50
287EG34
185EG48
185EG48
TDCLatest Timing
EX IN
BDC
To Advance Side
EX IN
EX IN
To Advance Side
EX IN
To Retard Side
Latest Timing
EX IN
Latest Timing
EX INEG-49
Effectiveness of the VVT-i System
Operation State
ObjectiveEffect
During Idling
At Light Load
Minimizing overlap to
reduce blowback to the
intake sideStabilized idling rpm
Better fuel economy
At Medium Load
Increasing overlap
increases internal EGR,
reducing pumping lossBetter fuel economy
Improved emission
control
In Low to Medium
Speed Range with
Heavy LoadAdvancing the intake
valve close timing for
volumetric efficiency
improvement
Improved torque in low
to medium speed range
In High Speed Range
with Heavy Load
Retarding the intake
valve close timing for
volumetric efficiency
improvement
Improved output
At LowTemperature
Minimizing overlap to
prevent blowback to
the intake side leads to
the lean burning
condition, and
stabilizes the idling
speed at fast idle
Stabilized fast
idle rpm
Better fuel economy
Upon Starting
Stopping the
Engine
Minimizing overlap to
minimize blowback to
the intake side
Improved startability

ENGINE - 2AZ-FE ENGINE
169EG36
HousingLock Pin
Intake Camshaft
Vane (Fixed on Intake Camshaft)
Oil Pressure
At a Stop In Operation
Lock Pin
221EG17
To VVT-i Controller
(Advance Side)To V V T- i C o n t r o l l e r
(Retard Side)
Sleeve
Spring
Drain
Oil PressureDrain
Spool ValveCoil
Plunger EG-50
Construction
1) VVT-i Controller
This controller consists of the housing driven by the timing chain and the vane fixed on the intake
camshaft.
The oil pressure sent from the advance or retard side path at the intake camshaft causes rotation in the
VVT-i controller vane circumferential direction to vary the intake valve timing continuously.
When the engine is stopped, the intake camshaft will be in the most retarded state to ensure startability.
When hydraulic pressure is not applied to the VVT-i controller immediately after the engine has been
started, the lock pin locks the movement of the VVT-i controller to prevent a knocking noise.
2) Camshaft Timing Oil Control Valve
This camshaft timing oil control valve controls the spool valve position in accordance with the duty-cycle
control from the ECM. This allows hydraulic pressure to be applied to the VVT-i controller advance or
retard sides. When the engine is stopped, the camshaft timing oil control valve is in the most retarded
state.

ENGINE - 2AZ-FE ENGINE
198EG35
Va n e
Rotation DirectionOil PressureECM
IN Drain
198EG36
Va n e
Rotation DirectionOil Pressure
Drain INECMEG-51
Operation
1) Advance
When the camshaft timing oil control valve is operated as illustrated below by the advance signals from
the ECM, the resultant oil pressure is applied to the advance side vane chamber to rotate the camshaft
in the advance direction.
2) Retard
When the camshaft timing oil control valve is operated as illustrated below by the retard signals from
the ECM, the resultant oil pressure is applied to the retard side vane chamber to rotate the camshaft in
the retard direction.
3) Hold
After reaching the target timing, the valve timing is held by keeping the camshaft timing oil control valve
in the neutral position unless the traveling state changes.
This adjusts the valve timing at the desired target position and prevents the engine oil from running out
when it is unnecessary.

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 - 2AZ-FE ENGINE
00REG18Y
Front Airbag
Sensor
(RH and LH)
Curtain Shield
Airbag Sensor*
(RH and LH)Airbag
Sensor
Side Airbag
Sensor*
(RH or LH)ECMCircuit
Opening
Relay
Fuel
Pump
Motor
: CANEG-53
9. Fuel Pump Control
A fuel cut control is used to stop the fuel pump when the SRS airbag is deployed at the front collision. In this
system, the airbag deployment signal from the airbag sensor is detected by the ECM, which turns OFF the
circuit opening relay.
After the fuel cut control has been activated, turning the ignition switch from OFF to ON cancels the fuel cut
control, and the engine can be restarted.
*: Models with SRS Driver, Front Passenger, Side and Curtain Shield Airbags