Page 19 of 2000
ENGINE - 2AZ-FE ENGINE
01MEG30Y
Fuel Pump Assembly
Fuel Filter
Pressure Regulator
Quick Connector
Injector
Fuel Tank
Canister EG-22
FUEL SYSTEM
1. General
The fuel returnless system is used to reduce evaporative emissions.
A fuel cut control is used to stop the fuel pump when the SRS airbag is deployed in a front or side collision.
For details, see page EG-53.
A quick connector is used in the fuel main pipe to improve serviceability.
The 12-hole type fuel injector is used.
The ORVR (On-board Refueling Vapor Recovery) system is used. For details, see page EG-54.
Page 20 of 2000
ENGINE - 2AZ-FE ENGINE
185EG16
Pulsation
Dumper
Pressure Regulator
Fuel Pump
AssemblyFuel Tank
Fuel Filter
Fuel Pump
DR011EG18
EG-23
2. Fuel Returnless System
Fuel returnless system is used to reduce the evaporative emission. As shown below, by integrating the fuel
filter and pressure regulator with fuel pump assembly, the fuel return system in which the fuel returns from
the engine area is discontinued and temperature rise inside the fuel tank is prevented.
3. Fuel Injector
The 12-hole type injector is used. By modifying its
injector nozzle to a taper shape, this injector has
achieved high atomizing performance of fuel. In
addition, the injector provides good performance
with the lightweight moving parts and the
optimized magnetic circuit.
Page 27 of 2000

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)
Page 29 of 2000

ENGINE - 2AZ-FE ENGINE
01MEG04Y
SENSORSACTUATORS
MASS AIR FLOW METER
INTAKE AIR TEMPERATURE
SENSOR
ENGIEN COOLANT
TEMPERATURE SENSOR
THROTTLE POSITION
SENSOR
CRANKSHAFT POSITION
SENSOR
CAMSHAFT POSITION
SENSOR
ACCELERATOR PEDAL
POSITION SENSOR
AIR-FUEL RATIO SENSOR
(Bank 1, Sensor 1)
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)
KNOCK SENSOR
COMBINATION METER
Vehicle Speed Signal
IGNITION SWITCH
Ignition Signal
Starter Signal
PA R K / N E U T R A L P O S I T I O N
SWITCH
TRANSMISSION CONTROL
SWITCH
CRUISE CONTROL SWITCHVG
THA
THW
VTA1
VTA2
NE
G2
VPA
VPA2
A1A
OX1B
KNK1
SPD
IGSW
STA
D, 2, L
R, P, N
3
CCSECM#10
#20
#30
#40
IGT1 IGT4
IGF1
M
OC1
FC
HA1A
HT1BSFI
No.1 INJECTOR
No.2 INJECTOR
No.3 INJECTOR
No.4 INJECTOR
ESA
IGNITION COIL
with IGNITER
SPARK PLUGS
ETCS-i
THROTTLE CONTROL
MOTOR
VVT-i
CAMSHAFT TIMING OIL
CONTROL VALVE
FUEL PUMP CONTROL
CIRCUIT OPENING
RELAY
AIR-FUEL RATIO AND
HEATED OXYGEN SENSOR
HEATER CONTROL
AIR-FUEL RATIO SENSOR
HEATER (Bank1, Sensor1)
HEATED OXYGEN SENSOR
HEATER (Bank1, Sensor2)
EG-32
2. Construction
The configuration of the engine control system in the 2AZ-FE engine is shown in the following chart.
(Continued)
Page 31 of 2000
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
Page 32 of 2000
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
Page 46 of 2000

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
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