11
ENGINE — 1MZ-FE ENGINE 36 ENGINE CONTROL SYSTEM J DESCRIPTION The construction and functions of the new 1MZ-FE engine includes the following modifications and addi- tions in comparison with the 1MZ-FE engine installed on the ’98 ES300 as the base: System Outline RX300 ’98 ES300 SFI Sequential Multipot Fuel Injection The newly adopted L-type SFI system directly mea- sures the intake air flow by means of the hot-wire type air flow meter. f f The newly adopted air assisted fuel injection system fa- cilitates fuel atomization for the improvement of emis- sion control performance and fuel economy. f f ESA Electronic Spark Advance Ignition timing is determined by the ECM based on sig- nals from various sensors. Corrects ignition timing in response to engine knocking. f f The torque control correction during gear shifting has been used to minimized the shift shock. f f 2 knock sensors are used to further improve knock detection. f f IAC (Idle Air Control) A rotary solenoid type IAC system controls the first idle and idle speeds. f (1-Coil Type) f (2-Coil Type) VVT-i Variable Valve Timing- intelligent Controls the intake camshaft to an optimal valve timing in accordance with the engine condition. f ACIS Acoustic Control Induction System This system changes the intake manifold length over in three stages according to the engine rpm and throttle valve opening to improve the performance at all engine speeds. f Active Control Engine Mount The damper characteristic of the front engine mount in- sulator is varied to reduce idling vibration. f A/F Sensor and Oxygen Sensor Heater Control Maintain the temperature of the A/F sensor and oxygen sensors at an appropriate level to increase accuracy of detection of the oxygen concentration in the exhaust gas. f f Air Fuel Ratio Feedback control The precision air fuel ratio feedback control has been improved through the adoption of the air-fuel ratio sen- sor and oxygen sensor. f f* Engine Immobilizer Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid ignition key. f f Function to communicate with multiplex communication system Communicates with the body ECM, A/C ECU, etc., on the body side, to input/output necessary signals. f *: Calfornia only

1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

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Page 1: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE36

ENGINE CONTROL SYSTEM

�DESCRIPTION

The construction and functions of the new 1MZ-FE engine includes the following modifications and addi-tions in comparison with the 1MZ-FE engine installed on the ’98 ES300 as the base:

System Outline RX300 ’98 ES300

SFISequentialMultipot FuelInjection

The newly adopted L-type SFI system directly mea-sures the intake air flow by means of the hot-wire typeair flow meter.

� �

The newly adopted air assisted fuel injection system fa-cilitates fuel atomization for the improvement of emis-sion control performance and fuel economy.

� �

ESAElectronic SparkAdvance

Ignition timing is determined by the ECM based on sig-nals from various sensors. Corrects ignition timing inresponse to engine knocking.

� �

The torque control correction during gear shifting hasbeen used to minimized the shift shock. � �

2 knock sensors are used to further improve knockdetection. � �

IAC(Idle Air Control)

A rotary solenoid type IAC system controls the firstidle and idle speeds.

�(1-Coil Type)

�(2-Coil Type)

VVT-iVariable ValveTiming-intelligent

Controls the intake camshaft to an optimal valve timingin accordance with the engine condition. � —

ACISAcoustic ControlInductionSystem

This system changes the intake manifold length over inthree stages according to the engine rpm and throttlevalve opening to improve the performance at all enginespeeds.

� —

Active ControlEngine Mount

The damper characteristic of the front engine mount in-sulator is varied to reduce idling vibration. � —

A/F Sensor andOxygen SensorHeater Control

Maintain the temperature of the A/F sensor and oxygensensors at an appropriate level to increase accuracy ofdetection of the oxygen concentration in the exhaustgas.

� �

Air Fuel RatioFeedback control

The precision air fuel ratio feedback control has beenimproved through the adoption of the air-fuel ratio sen-sor and oxygen sensor.

� �*

EngineImmobilizer

Prohibits fuel delivery and ignition if an attempt ismade to start the engine with an invalid ignition key. � �

Function tocommunicate withmultiplexcommunicationsystem

Communicates with the body ECM, A/C ECU, etc., onthe body side, to input/output necessary signals. � —

*: Calfornia only

Page 2: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE 37

�CONSTRUCTION

The configuration of the engine control system in the new 1MZ-FE engine for RX300 is as shown in thefollowing chart. Shaded portions differ from the 1MZ-FE engine for ’98 ES300.

W

STA

PRE

CF

PS

STP

PTNK

TRCENG

TC

SIL

SENSORS

MASS AIR FLOW METER

CRANKSHAFT POSITION SENSOR(Crankshaft Angle Signal)

VVT CAM ANGLE SENOSR

ENGINE COOLANT TEMP. SENSOR

ACTUATORS

ECM

Right Bank

Left Bank

INTAKE AIR TEMP. SENSOR

THROTTLE POSITION SENSOR(Throttle Position Signal)

IGNITION SWITCH

VEHICLE SPEED SENSOR

COMBINATION METER

HEATED OXYGEN SENSOR

KNOCK SENSOR(Right Bank & Left Bank)

NEUTRAL START SWITCH

STARTER RELAY

A/C COMP PRESSURE SWITCH

COOLING FAN RELAY

POWER STEERING OIL PRESSURE SWITCH

STOP LIGHT SWITCH

VAPOR PRESSURE SENSOR

TRAC ECU*

DATA LINK CONNECTOR 1

DATA LINK CONNECTOR 3

TRANSPONDER KEYAMPLIFIER

AIR FUEL RATIO SENSOR(Right Bank & Left Bank)

EFI MAIN RELAY

EFI

No. 1 ~ No. 6 INJECTOR

ESA

IGNITION COIL with IGNITER

SPARK PLUGS

IAC

CONTROL VALVE

FUEL PUMP CONTROL

CIRCUIT OPENING RELAY

AIR CONDITIONING CONTROL

AIR CONDITIONING ECU

HEATED OXYGEN SENSOR HEATER

VVT-i CONTROL

VVT-i Solenoid VSV RH

EVAP CONTROL

VSV

VAPOR PRESSURE CONTROL

VSV

VVT-i Solenoid VSV LH

MALFUNCTION INDICATOR LAMP

AIR FUEL RATIO SENSOR HEATER(Right Bank & Left Bank)

MULTIPLEX COMMUNICATION SYSTEM

BODY ECU

AIR CONDITIONER/METER ECU

BATTERY

VG

NE

VV1

VV2

THW

THA

VTA1

IGSW

STA

SPD

OXS

KNKR

KNKL

NSW

TXCTRXCK

CODE

AFR

AFL

+B

#10~#60

IGT1~6

RSO

FC

ACMG

HTS

OC1

OC2

EVAP1

TPC

IMLD

BATT

MPX1

MPX2

HAFRHAFL

THEFT DETERRENT INDICATOR LIGHT LAMP*2

*: Applicable only to vehicles equipped with the TRAC System.

Page 3: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE38

�ENGINE CONTROL SYSTEM DIAGRAM

157EG20

ABS Unit

Meter UnitFuel PressureControlRelay

StartSwitch

FuelPressureRegulator

Vehicle Speed Signal

MIL

Fuel PumpBattery

A/CAmplifier

DLC3

Park/Neutral Position Switch

Electronic ControlledTransmissionSolenoid Valves

Stop Light SwitchElectric Load Switch

ECMORVRBreatherLine

VSV (for EVAPPurge Control)

PressureSensorVSV(PressureControl)

VSV (for AcousticControl InductionSystem)

IAC Valve

Intake Air Temp.Sensor

Mass AirFlow Meter

Throttle Position Sensor

A/F Sensor

Camshaft PositionSensor

Oil Control Valve

Warm-Up-TWC ECT Sesnor

RPM Sensor Knock Sensor

Warm-Up-TWCA/F Sensor

TWC

CamshaftPositionSensor

Injector

Oil Control Valve(for VVT Control)

EI

Fuel Filter

Heated Oxygen Sensor

Page 4: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE 39

�LAYOUT OF COMPONENTS

157EG21

Knock Sensor

IAC Valve

Throttle Position Sensor

O2 Sensor

ECM

Cam Position Sensor

Air Flow Meter

OCVCam Position Sensor

A/F Sensor

Crank Position Sensor

InjectorWater TemperatureSensor

Ignition Coilwith Built-inIgnite

Page 5: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE40

�VVT-i CONTROL SYSTEM

General

� This system controls the intake camshaft valve timing so as to obtain balance between the engine output,fuel consumption and emission control performance. The actual intake side valve timing is fed backby means of the cam position sensor for constant control to the target valve timing.

157EG22

Throttle Position Sensor

OCV (RH bank)

Cam Position Sensor (RH bank)

OCV (LH bank)

Cam Position Sensor (LH bank)

Water Temperature SensorECM

AirFlow Meter

Crank Position Sensor

157EG23

ECM

Target Valve Timing

Actual Valve Timing

Correction

Feedback

OCV

Duty Control

Crank Position Sensor

Air Flow Meter

Throttle Position Sensor

Water Temperature Sensor

Cam Position Sensor

Page 6: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE 41

�CONSTRUCTION AND FUNCTIONS

Construction

The camshaft on the exhaust side is driven by the timing belt from the crankshaft pulley, and the camshafton the intake side is driven by the gear train from the exhaust side.The camshaft drive gear (exhaust side) is combined with a scissors gear to reduce the gear noise due totorque variation. The camshaft driven gear (intake side) is integrated with the VVT-i actuator to vary theintake camshaft valve timing.

157EG22

157EG24

Crankshaft TimingPulley

Timing BeltDrive Gear(scissors gear)

Driven gear(VVT-i Actuator)

Exhaust Camshaft

Intake Camshaft

Valve timingVarying Portion

Intake Camshaft

VVT-i Actuator

Cam Position Sensor

Exhaust Camshaft

CrankshaftCam Position Sensor Cam Position Sensor

VVT-i Actuator

Page 7: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE42

The ECM distributes the pressure generated by the oil pump into the advance side and retard side by meansof the OCV (oil control valve) installed on the side wall of the cylinder head for adjusting the pressuresbefore and after the VVT-i controller vane to control the intake camshaft phase.

VVT-i Controller

This controller consists of the housing driven from the exhaust camshaft and the vane coupled with theintake camshaft.The oil pressure sent from the advance or retard side path at the intake camshaft causes rotation in theVVT-i controller vane circumferential direction to vary the intake valve timing continuously.

157EG25

Driven Gear

Housing (fixed on driven gear) Vane Seal

Vane Portion(fixed on intake camshaft)

This illustration shows theangle advance state.

OCV (Oil Control Valve)

The oil control valve spool position is varied to constantly obtain the optimum valve timing accordingto the duty signal sent from the ECM.The latest timing position is set by the spring force while the engine is stopped.

157EG26

VVT-i Pulley TimingAdvance Chamber

VVT-i Pulley TimingRetard Chamber

Spool Valve

Connector

PlungerCoilDrainDrain

Oil PressureSpring

Sleeve

Page 8: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE

VVT-i Actuator

ECM

Fluid Pressure

Advance Signal

Duty Ratio

Retard Signal

Duty Ratio

Hold Signal

Duty Ratio

ECM

Fluid Pressure

ECM

Fluid Pressure

Vane(fixed on intakecamshaft)

157EG27 157EG28

157EG29 157EG30

157EG31 157EG32

Rotating Direction

157EG36

157EG37

157EG35

43

Operation (Hydraulic System)

The OCV selects the path to the VVT-i actuator according to the advance, retard or hold signal from theECM. The VVT-i actuator rotates the camshaft in the timing advance or retard position or holds it accordingto the position where the fluid pressure is applied.

Operation OCV drive signal Description

Adv

ance

When the OCV is positionedas illustrated at left by the ad-vance signal from the ECM,the resultant fluid pressure isapplied to the timing advanceside vane chamber to rotatethe camshaft in the timing ad-vance direction.

Del

ay

When the OCV is positionedas illustrated at left by the re-tard signal from the ECM, theresultant fluid pressure is ap-plied to the timing retard sidevane chamber to rotate thecamshaft in the timing retarddirection.

Hol

d

The ECM calculates the tar-get timing angle according tothe traveling state to performcontrol as described above.After setting at the target tim-ing, the valve timing is heldby keeping the OCV in theneutral position unless thetraveling state changes.This adjusts the valve timingat the desired target positionand prevents the engine oilfrom running out when it isunnecessary.

Page 9: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE

IN

�IN

IN �

IN�

IN �

IN

IN

Latest timing

Latest timing

Latest timing

To retard side

To retard side

To advance side

To advance side

EX

EX

EX

EX

EX

EX

EX

44

ECM

In proportion to the engine speed, intake air volume, throttle position and coolant temperature, the ECMsearches an optimal valve timing under each driving condition and control the camshaft timing oil controlvalve. In addition, ECM uses signal from the VVT sensors and the crankshaft position sensor to detectthe actual valve timing, thus performing feedback control to achieve the target valve timing.

� Operation During Various Driving Condition �

151EG74

Eng

ine

Loa

d

Range 4

Range 1 Engine Speed

Range 2

Range 3

Range 5

Full Load Perfomance

Operation state Range Valve timing Objective Effect

During idling 1Eliminating overlap to re-duce blow back to the in-take side

Stabilized idling rpmBetter fuel economy

At light load 2Decreasing overlap toeliminate blow back to theintake side

Ensured engine stability

At mediumload

3Increasing overlap to in-crease internal EGR forpumping loss elimination

Better fuel economyImproved emission con-trol

In low tomedium speedrange withheavy load

4Advancing the intake valveclose timing for volumetricefficiency improvement

Improved torque in lowto medium speed range

In high speedrange withheavy load

5Retarding the intake valveclose timing for volumetricefficiency improvement

Improved output

At lowtemperatures —

Eliminating overlap to pre-vent blow back to the in-take side for reduction offuel increase at low temper-atures, and stabilizing theidling rpm for decreasingfast idle rotation

Stabilized fast idle rpmBetter fuel economy

Upon starting/stopping theengine

—Eliminating overlap toeliminate blow back to theintake side

Improved startability

Page 10: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE 45

�SFI (Sequential Multipot Fuel Injection) SYSTEM

� The L-type SFI system is adopted to adjust fuel injection volume by directly measuring the intake airflow with a hot-wire type air flow meter.

� An air assist type fuel injection system is adopted to improve emission control and fuel economy befacilitating fuel atomization.

Air-Fuel Ratio and Feedback Control

As illustrated below, the conventional oxygen sensor is characterized by a sudden change in its outputvoltage at the threshold of the stoichiometric air-fuel ratio (14.7 to 1). In contrast, the air-fuel ratio sensoroutput a voltage that is approximately proportionate to the existing air-fuel ratio by converting the oxygendensity to the voltage. As a result, the detection precision of the air-fuel ratio has been improved.

151EG30

151EG31

Air-FuelRatio Sensor

AF+

AF−3.0V

3.3V

ECM

Air-Fuel Ratio Sensor

(V)4.2

(V)1

0.12.2

11 14.7 19

Oxygen SensorA

ir-Fu

el R

atio

Sen

sor

Out

put

Oxy

gen

Sens

orO

utpu

t

Air-Fuel Ratio

Output Characteristics

The precision of the air-fuel feedback control has been improved through the adoption of the air-fuel ratiosensor. As illustrated below, if the existing air-fuel ratio diverts from the stoichiometric air-fuel ratio, theconventional oxygen sensor used to correct the air-fuel ratio at a constant proportion. However, with theair-fuel ratio sensor, the ECM can determine the extent of diversion from the stoichiometric air-fuel ratioand execute an immediate correction.

151EG32

Rich�

StoichiometricAir-Fuel Ratio

�Lean

InjectionVolume

Previous(Oxygen Sensor)

New(Air FuelRatio Sensor)

DisorderNew

Previous

Correction at aConstant Proportion

Immediate Correction

Page 11: 1MZ-FE Engine Control System - alflash.com.uaalflash.com.ua/RX/1MZ-FE_Engine_Control_SystemRX300_99.pdf · sures the intake air flow by means of the hot-wire type air flow meter

ENGINE — 1MZ-FE ENGINE46

�ACIS (ACOUSTIC CONTROL INDUCTION SYSTEM) CONTROL

General

The ECM intake control valve is opened/closed according to the engine rpm and throttle valve openingto vary the intake manifold length in three stages for improving the torque under heavy load in the mediumspeed range.

Operation

Relationships between engine rpm and throttle valve opening

1 Engine speed below 2,700 rpm and throttle valve opening at 30 degrees or more (Low speed range withheavy load)

2 Engine speed between 2,700 and 3,700 rpm and throttle valve opening at 30 degrees or more (Mediumspeed range with heavy load)

3 Engine speed up to 3,700 rpm with throttle valve opening at 30 degrees or less, and full range withengine speed above 3,700 rpm (Idling range, light load range and high speed range)

1 Low speed range with heavy load

2 Medium speed range with heavy load

3 Idling range, light load range and high speed range

157EG10

157EG11

157EG12

Engine rpm

2700r/min 3700r/min

1 2 3

3 3

30°

157EG33

Thr

ottle

Val

ve O

peni

ng