sensor TOYOTA RAV4 2006 Service User Guide

ENGINE - 2AZ-FE ENGINE
00REG21Y
D13N11
Air-fuel
Ratio
SensorA1A+
(3.3V)
A1A -
(2.9V)ECMHeated
Oxygen
SensorOX1B
EX1BECM
Air-fuel Ratio Sensor Circuit Heated Oxygen Sensor
: Air-fuel Ratio Sensor
: Heated Oxygen Sensor
Air-fuel Ratio Sensor Data
Displayed on Hand-held
Te s t e r4.2
2.2
11 (Rich) 14.7 19 (Lean)0.11
Heated Oxygen
Sensor Output (V)
Air-fuel RatioEG-37
Air-fuel Ratio Sensor and Heated Oxygen Sensor
1) General
The air-fuel ratio sensor and heated oxygen sensor differ in output characteristics.
Approximately 0.4V is constantly applied to the air-fuel ratio sensor, which outputs an amperage that
varies in accordance with the oxygen concentration in the exhaust emission. The ECM converts the
changes in the output amperage into voltage in order to linearly detect the present air-fuel ratio. The
air-fuel ratio sensor data is read out by the hand-held tester.
The output voltage of the heated oxygen sensor changes in accordance with the oxygen concentration
in the exhaust emission. The ECM uses this output voltage to determine whether the present air-fuel
ratio is richer or leaner than the stoichiometric air-fuel ratio.

ENGINE - 2AZ-FE ENGINE
271EG45
Alumina
Dilation Layer
Alumina
Platinum
Electrode
Sensor Element (Zirconia)Heater AtmospherePlatinum
ElectrodeHeater
Atmosphere
Sensor Element
(Zirconia)
Planar Type Air-fuel Ratio Sensor Cup Type Heated Oxygen Sensor
204EG54
Temperature Sensing
Element
Platinum Hot-wire
ElementAir FlowIntake Air
Temperature
Sensor EG-38
2) Construction
The basic construction of the air-fuel ratio sensor and heated oxygen sensor is the same. However, they
are divided into the cup type and the planar type, according to the different types of heater construction
that are used.
The cup type sensor contains a sensor element that surrounds a heater.
The planar type sensor uses alumina, which excels in heat conductivity and insulation, to integrate a
sensor element with a heater, thus realizing the excellent warm-up performance of the sensor.
Warm-up Specification
Sensor TypePlanar TypeCup Type
Warm-up TimeApprox. 10 sec.Approx. 30 sec.
Mass Air Flow Meter
The compact and lightweight mass air flow meter, which is a plug-in type, allows a portion of the intake
air to flow through the detection area. By directly measuring the mass and the flow rate of the intake air,
the detection precision is ensured and the intake air resistance is reduced.
This mass air flow meter has a built-in intake air temperature sensor.

ENGINE - 2AZ-FE ENGINE
214CE04
: Conventional Type
: Flat Type
(V)
Vo l t a g e
Frequency (Hz)A
BA: Detection Band of
Conventional Type
B: Detection Band of
Flat Type
Characteristic of Knock Sensor
214CE01214CE02
Steel Weight
Insulator
Piezoelectric
ElementOpen / Short Circuit
Detection Resistor
Flat Type Knock Sensor
(Non-resonant Type)Piezoelectric
Element
Vibration Plate
Conventional Type Knock Sensor
(Resonant Type)EG-39
Knock Sensor (Flat Type)
1) General
In the conventional type knock sensor (resonant type), a vibration plate which has the same resonance
point as the knocking frequency of the engine is built in and can detect the vibration in this frequency
band.
On the other hand, a flat type knock sensor (non-resonant type) has the ability to detect vibration in a
wider frequency band from about 6 kHz to 15 kHz, and has the following features.
The engine knocking frequency will change a bit depending on the engine speed. The flat type knock
sensor can detect the vibration even when the engine knocking frequency is changed. Thus the
vibration detection ability is increased compared to the conventional type knock sensor, and a more
precise ignition timing control is possible.
2) Construction
The flat type knock sensor is installed on the engine through the stud bolt installed on the cylinder
block. For this reason, a hole for the stud bolt is running through the center of the sensor.
Inside of the sensor, a steel weight is located on the upper portion and a piezoelectric element is located
under the weight through the insulator.
The open / short circuit detection resistor is integrated.

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).

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
00SEG39Y
228TU25 228TU24
A
AInternal Construction
A - A Cross SectionAccelerator
Pedal Arm
Hall IC
Magnetic Yoke
Accelerator Pedal
Position Sensor
Magnetic Yoke
Hall
IC
Hall
IC
VPA
EPA
VCPA
VPA2
EPA2ECM
Output
Voltage(V)
5
0VPA2
VPA
Fully Close Fully Open90
Accelerator Pedal Depressed Angle VCP2
Service Tip
The inspection method differs from the conventional contact type accelerator pedal position sensor
because this non-contact type sensor uses a Hall IC.
For details, refer to the 2006 RAV4 Repair Manual (Pab. No. RM01M0U).
EG-42
Accelerator Pedal Position Sensor
The non-contact type accelerator pedal position sensor uses a Hall IC.
The magnetic yoke that is mounted at the accelerator pedal arm rotates around the Hall IC in accordance
with the amount of effort that is applied to the accelerator pedal. The Hall IC converts the changes in the
magnetic flux at that time into electrical signals, and outputs them as accelerator pedal effort to the ECM.
The Hall IC contains circuits for the main and sub signals. It converts the accelerator pedal depressed
angles into electric signals with two differing characteristics and outputs them to the ECM.

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.