Lexus ES300 (2002 year). Manual - part 133

ENGINE – 1MZ-FE ENGINE

EG-55

199EG47

Injectors

ECM

Ignition Coil

Accelerator Pedal
Position Sensor

Main

Sub

Main

Sub

Open

Throttle
Valve

Return 
Spring

Throttle
Control
Motor

Accelerator Pedal

Throttle Body

Fail-Safe of Throttle Position Sensor

 The throttle position sensor comprises 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, 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. 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 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 sys-

tem.

ENGINE – 1MZ-FE ENGINE

EG-23

211EG10

Pulsation Damper

Fuel Tank

ORVR Valve

Injector

Fuel Pump

 Pressure Regulator

 Sender Gauge

 Fuel Filter

FUEL SYSTEM

1. General

 A fuel returnless system has been used to reduce evaporative emissions.
 A compact fuel pump in which a fuel filter and pressure regulator are integrated in the module fuel pump

assembly has been adopted.

 A quick connector has been adopted to connect the fuel pipe with the fuel hose to improve serviceability.
 A compact 12-hole type injector with high atomizing performance has been adopted to improve the atom-

ization of fuel. As the result, the air assist system used on ’01 ES300 has been discontinued.

 A tether has been provided on the fuel filter cap to prevent the cap from being lost, which results in prevent-

ing the leakage of fuel or the evaporative gas.

 The quick-turn type fuel tank cap has been newly adopted to improve usability.
 The ORVR (On-board Refueling Vapor Recovery) system has been adopted. For details, see page xx.

ENGINE – 1MZ-FE ENGINE

EG-24

208EG117

Pulsation
Damper

Fuel Filter

Fuel Pump

Pressure Regulator

Module Fuel 
Pump Assembly

Fuel Tank

208EG118

A

View A

2. Fuel Returnless System

This system has been adopted to reduce the evaporative emission. As shown below, integrating the fuel filter,
pressure regulator, and fuel sender gauge with fuel pump assembly, it possible to discontinue the return of
fuel from the engine area and prevent temperature rise inside the fuel tank.

3. Fuel Injector

The 12-hole type injector has been adopted to im-
prove the atomization of fuel.

ENGINE – 1MZ-FE ENGINE

EG-25

208EG19

Sender Gauge

Fuel Pressure 
Regulator

Fuel Pump Filter

Fuel Pump

Strainer

4. Fuel Pump

A compact fuel pump in which a fuel pump filter, fuel pressure regulator, and sender gauge are integrated
in the fuel pump assembly has been adopted.

 Specification of Fuel Pressure Regulator 



Adjusting Pressure

kPa (kgf / cm

2

)

324 

±

 3.0

(3.3 

±

 0.03)