Page 36 of 2000

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.
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 40 of 2000

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
Page 44 of 2000

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.
Page 50 of 2000
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
Page 51 of 2000

ENGINE - 2AZ-FE ENGINE
Service Tip
The canister pump module performs the EVAP leak check. This check is done approximately five
hours after the engine is turned off. So you may hear sound coming from underneath the luggage
compartment for several minutes. It does not indicate a malfunction.
The pinpoint pressure test procedure is carried out by pressurizing the fresh air line that runs from
the pump module to the air filler neck. For details, refer to the 2006 RAV4 Repair Manual (Pub.
No. RM01M1U).
EG-54
10. EVAP (evaporative Emission) Control System
General
The EVAP (evaporative emission) control system prevents the vapor gas that is created in the fuel tank from
being released directly into the atmosphere.
The canister stores the vapor gas that has been created in the fuel tank.
The ECM controls the purge VSV in accordance with the driving conditions in order to direct the vapor
gas into the engine, where it is burned.
In this system, the ECM checks the evaporative emission leak and outputs DTC (Diagnostic Trouble
Code) in the event of a malfunction. An EVAP (evaporative emission) leak check consists of an
application of a vacuum pressure to the system and monitoring the changes in the system pressure in order
to detect a leakage.
This system consists of the purge VSV, canister, refueling valve, canister pump module, and ECM.
The ORVR (Onboard Refueling Vapor Recovery) function is provided in the refueling valve.
The canister pressure sensor has been included to the canister pump module.
The canister filter has been provided on the fresh air line. This canister filter is maintenance-free.
The followings are the typical conditions for enabling an EVAP leak check:
Typical Enabling
Condition
Five hours have elapsed after the engine has been turned OFF*.
Altitude: Below 2400 m (8000 feet)
Battery voltage: 10.5 V or more
Ignition switch: OFF
Engine coolant temperature: 4.4 to 35C (40 to 95F)
Intake air temperature: 4.4 to 35C (40 to 95F)
*: If engine coolant temperature does not drop below 35C (95F), this time should be extended to 7hours.
Even after that, if the temperature is not less than 35
C (95F), the time should be extended to 9.5 hours.
Page 57 of 2000
ENGINE - 2AZ-FE ENGINE
00REG25Y
D13N22
Atmosphere
Purge VSV
(OFF)
ECMCanister Pump Module
Ve n t Va l v e
(OFF)
Leak Detection Pump
& Pump Motor
Canister
Pressure Sensor
Purge VSV
Vent Valve
Pump Motor
System PressureON (Open)
OFF (Close)
ON
OFF (Vent)
ON
OFF
Atmospheric Pressure
0.02 in. Leak Pressure
Atmospheric Pressure Measurement
P
M
EG-60
b. Atmospheric Pressure Measurement
1) When the ignition switch is turned OFF, the purge VSV and vent valve are turned OFF. Therefore,
the atmospheric pressure is introduced into the canister.
2) The ECM measures the atmospheric pressure through the signals provided by the canister pressure
sensor.
3) If the measurement value is out of standards, the ECM actuates the leak detection pump in order
to monitor the changes in the pressure.
Page 65 of 2000
ENGINE
ENGINE - 2AZ-FE ENGINE
01NEG49Y
01NEG50Y
EG-2
2AZ-FE ENGINE
DESCRIPTION
The 2AZ-FE engine is an in-line, 4-cylinder, 2.4-liter, 16-valve DOHC engine. This engine uses the VVT-i
(Variable Valve Timing-intelligent) system, DIS (Direct Ignition System), ETCS-i (Electronic Throttle
Control System-intelligent). It has been developed to realize high performance, quietness, fuel economy and
clean emission.