Lexus ES300 (2002 year). Manual — part 136

ENGINE – 1MZ-FE ENGINE

EG-35

199EG35

Thermistor

Platinum Hot-wire

Air Flow

Intake Air
Temp.
Sensor

5. Main Components of Engine Control System

General

The following table compares the main components.

Components

New

Previous

Components

Outline

Quantity

Outline

Quantity

ECM

32-bit CPU

1

16-bit CPU

1

Mass Air Flow Meter

Hot-wire Type

1

Crankshaft Position Sensor
(Rotor Teeth)

Pick-up Coil Type

(36-2)

1

VVT Sensor [Bank 1]
(Rotor Teeth)

Pick-up Coil Type

(3)

1

VVT Sensor [Bank 2]
(Rotor Teeth)

Magnetic Resistance

Element Type

(3)

1

Pick-up Coil Type

(3)

1

Throttle Position Sensor

Linear Type

1

Accelerator Pedal Position
Sensor

Linear Type

1

—

Knock Sensor

Built-in Piezoelectric

Type

2

Air Fuel Ratio Sensor
(Bank 1, Sensor 1)
(Bank 2, Sensor 1)

with Heater Type

2

Oxygen Sensor
(Bank 1, Sensor 2)
(Bank 2, Sensor 2)

with Heater Type

2

with Heater Type

1

Injector

12-Hole Type

6

4-Hole Type

6

Mass Air Flow Meter

This 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
has been improved and the intake air resistance has been reduced.

This mass air flow meter has a built-in intake air temperature sensor.

ENGINE – 1MZ-FE ENGINE

EG-36

208EG40

Engine
Front

Timing Rotor

Crankshaft
Position Sensor

Timing Rotor (720

CA)

10

CA

2 Teeth
Missing

211EG16

VVT Sensor

Timing
Rotor

Timing Rotor (720

CA)

240

CA 240 CA

240

CA

For
Right
Side

For Left
Side

240

CA 240 CA

240

CA

120

CA

Crankshaft Position Sensor

The timing rotor of the crankshaft consists of 34 teeth, with 2 teeth missing. The crankshaft position sensor
outputs the crankshaft rotation signals every 10

, and the missing teeth are used to determine the top-dead-

center.

VVT Sensor

The magnetic resistance element type VVT sensor is mounted on the left side of cylinder head and the con-
ventional type VVT sensor is mounted on the right side of cylinder head. To detect the camshaft position,
a timing rotor that is provided on the VVT-i controller is used to generate 3 pulses for every 2 revolutions
of the crankshaft.

ENGINE – 1MZ-FE ENGINE

EG-37

EG-37

208EG42

Throttle Position Sensor

Output
Voltage

E2

VTA2 VTA

VC

Close

Open

Close

Open

V

5.0

0

Close

VTA2

VTA

Open

208EG27

Close

Open

EP2 VPA2 VCP2

EP1 VPA VCP1

Open

Close

V

5.0

Output
Voltage

VPA2

VPA

0

Close

Open

Accelerator
Pedal Position Sensor

Throttle Position Sensor

This sensor converts the throttle valve opening angles into electronic signals with two differing characteris-
tics and outputs them to the ECM. One is the VTA signal that linearly outputs the voltage along the entire
range of the throttle valve opening angle. The other is the VTA 2 signal that outputs an offset voltage.

Accelerator Pedal Position Sensor

This sensor converts the accelerator pedal depressed angles into electric signals with two differing charac-
teristics and outputs them to the ECM. One is the VPA signal that linearly outputs the voltage along the entire
range of the accelerator pedal depressed angle. The other is the VPA2 signal that outputs on offset voltage.

ENGINE – 1MZ-FE ENGINE

EG-38

208EG43

Synchronous Injection

Ignition

Intake
Combustion

Non-Synchronous Injection

#1

#2

#3

#4

#5

#6

Independent Injection

Intake

Combustion

6. SFI (Sequential Multiport electronic Fuel Injection) System

An L-type SFI system directly detects the intake air mass with a hot wire type mass air flow meter.
An independent injection system (in which fuel is injected once into each cylinder for each two revolution

of the crankshaft) has been adopted.

There are two types of fuel injection:

a) One is synchronous injection in which corrections based on the signals from the sensors are added to

the basic injection duration so that injection occurs always at the same timing.

b) The other is non-synchronous injection in which injection is effected by detecting the requests from the

signals of the sensors regardless of the crankshaft angle.

Furthermore, to protect the engine and improve fuel economy, the system effects fuel cutoff in which the in-
jection of fuel is stopped temporarily in accordance with the driving conditions.

7. ESA (Electronic Spark Advance)

This system selects the optimal ignition timing in accordance with the signals received from the sensors and
sends the (IGT) ignition signal to the igniter. The default ignition timing is set to 5

BTDC.