
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
01MEG09Y
Accelerator Pedal
Position Sensor
Generator
MIL
DLC3Park / Neutral
Position Switch
Ignition
Switch
Circuit Opening RelayECM
Battery
Throttle
Position
Sensor
Throttle
Control
Motor
Purge VSVMass Air Flow Meter
Intake Air Temperature
Sensor
Camshaft Position
Sensor
Camshaft
Timing
Oil Control
Va l v e
Ignition Coil
with Igniter
Injector
Knock Sensor
Engine
Coolant
Temperature
Sensor
Crankshaft Position
Sensor
Canister
Filter
Fuel Pump
Canister Pump Module
Ve n t Va l v e
Leak Detection Pump
Canister Pressure SensorTWCs
Heated Oxygen Sensor
(Bank 1, Sensor 2)
Air-fuel Ratio Sensor
(Bank 1, Sensor 1) EG-34
3. Engine Control System Diagram

ENGINE - 2AZ-FE ENGINE
01MEG31Y
DLC3
Accelerator Pedal
Position Sensor
Mass Air Flow Meter
(Built-in Intake Air
Temperature Sensor)
VSV (for EVAP)
Battery Current
Sensor
Fuel Pump
Canister Pump Module
Ve n t Va l v e
Leak Detection Pump
Canister Pressure Sensor
ECM
Heated Oxygen Sensor
(Bank 1, Sensor 2) Air Fuel Ratio Sensor
(Bank 1, Sensor 1)
Camshaft Timing
Oil Control ValveInjectorKnock Sensor
Ignition Coil with Igniter
Throttle Position
Sensor
Camshaft Position
Sensor
Water Temperature
Sensor
Crakshaft Position
SensorEG-35
4. Layout of Main Components

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.

ENGINE - 2AZ-FE ENGINE
01NEG13Y
Generator
RegulatorB
DF
RLOECM
Various Electrical
Loads
Battery Current Sensor
Battery Temperature Sensor
Battery Voltage
Battery
Various Sensors and Switches
Throttle Position Sensor
Crankshaft Position Sensor
Accelerator Pedal Position
SensorEG-65
11. Charging Control
General
This system lowers the generated voltage when the vehicle is idling or is being driven at a constant speed,
and raises the generated voltage when the vehicle is decelerating. This reduces the load on the engine as
a result of the electric generation of the generator, thus contributing to the fuel economy of the engine.
During acceleration, this system regulates the generated voltage in order to place the amperage estimation
value close to the target value.
This control consists of the ECM, battery current sensor with a built-in battery temperature sensor,
generator, and various sensors and switches.
The ECM detects driving condition based on signals from various sensors and switches, and detects
charging condition based on signals from the generator, battery current sensor and battery temperature
sensor. Then the ECM outputs signals to the IC regulator to control the genetated voltage of the generator.
The ECM stops the charging control and the generator switches to normal power generation mode under
the following conditions:
Low battery capacity
Low or high battery temparature
Wipers operating or blower motor operating with tail lamp relay ON
System Diagram

ENGINE - 2AZ-FE ENGINE
258AS61 281EG86
Output
Voltage5 (V)
0
-100
Current+100 (A)
Characteristic of Current Sensor
288EG61C
(C) 60
Battery Temperature 0 Resistance(k
)
6 EG-66
Battery Current Sensor
Installed on the negative terminal of the battery, this sensor detects the amount of charging and discharging
amperage of the battery and sends signal to the ECM. Based on this signal, the ECM calculates the battery
capacity. A Hall IC is used for detecting the amount of charging and discharging amperage. The changes
that occur in the magnetic flux density in the core as a result of the charging and amperage of the battery
are converted and output as voltage.
Batter Temperature Sensor
The battery temperature sensor is built into the battery current sensor.
The battery characteristic (battery internal resistance) of taking in current for charging varies according
to battery electrolyte temperature. If the electrolyte temperature is too low or too high, the battery internal
resistance will increase, resulting in early deterioration. To prevent this, the battery temperature sensor
changes its resistance as shown below to detect the temperature.

ENGINE - 2AZ-FE ENGINE
Service Tip
To clear the DTC that is stored in the ECM, use a hand-held tester or disconnect the battery terminal
or remove the EFI fuse for 1 minute or longer.
EG-67
Fail-safe
Due to a failure in the battery current sensor or battery temperature sensor, the ECM may determine the
necessity of performing a fail-safe operation. Then, the ECM stops the charging control and the generator
switches to the normal power generation mode.
When the ECM detects a malfunction in a sensor, the ECM memorizes the DTC (Diagnostic Trouble Code).
The MIL (Malfunction Indicator Lamp) does not illuminate.
DTC Chart
DTC No.Detection ItemDTC No.Detection Item
P0516Battery Temperature Sensor
Circuit LowP1551Battery Current Sensor
Circuit Low
P0517Battery Temperature Sensor
Circuit HighP1552Battery Current Sensor
Circuit High
P0560System VoltageP1602Detection of Battery
P1550Battery Current Sensor
Circuit
12. Diagnosis
When the ECM detects a malfunction, the ECM makes a diagnosis and memorizes the failed section.
Furthermore, the MIL in the combination meter illuminates or blinks to inform the driver.
The ECM will also store the DTCs of the malfunctions. The DTCs can be accessed by the use of the
hand-held tester.
For details, refer to the 2006 RAV4 Repair Manual (Pub. No. RM01M1U).
13. Fail-safe
When a malfunction is detected at any of the sensors, there is a possibility of an engine or other malfunction
occurring if the ECM were to continue to control the engine control system in the normal way. To prevent
such a problem, the fail-safe function of the ECM either relies on the data stored in memory to allow the
engine control system to continue operating, or stops the engine if a hazard is anticipated. For details, refer
to the 2006 RAV4 Repair Manual (Pub. No. RM01M1U).