1NZ-FE Engine Control System

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ENGINE — 1NZ-FE ENGINE

JENGINE CONTROL SYSTEM 1. General The engine control system for the 1NZ-FE engine has following system. System SFI Sequential Multiport Fuel Injection ESA Electronic Spark Advance

Outline D An L-type SFI system directly detects the intake air volume with a hot-wire type mass air flow meter. D The fuel injection system is a sequential multiport fuel injection system. D Ignition timing is determined by the ECM based on signals from various sensors. The ECM corrects ignition timing in response to engine knocking. D In vehicles equipped with automatic transaxle, torque control correction during gear shifting has been used to minimize the shift shock.

IAC (Idle Air Control)

A rotary solenoid type IAC valve controls the fast idle and idle speeds.

VVT-i Variable Valve Timing-intelligent

Controls the intake camshaft to an optimal valve timing in accordance with the engine condition.

Fuel Pump Control

Fuel pump operation is controlled by signal from the ECM.

Oxygen Sensor Heater Control

Maintains the temperature of the oxygen sensors at an appropriate level to increase accuracy of detection of the oxygen concentration in the exhaust gas.

Evaporative Emission Control

The ECM controls the purge flow of evaporative emissions (HC) in the charcoal canister in accordance with engine conditions.

Air Conditioning Cut-Off Control

By turning the air conditioning compressor OFF in accordance with the engine condition, drivability is maintained.

Cooling Fan Control

Radiator cooling fan operation is controlled by signals from ECM based on the engine coolant temperature sensor signal (THW).

Diagnosis

When the ECM detects a malfunction, the ECM diagnoses and memorizes the failed section.

Fail-Safe

When the ECM detects a malfunction, the ECM stops or controls the engine according to the data already stored in memory.

2000 ECHO (NCF 171U)

ENGINE — 1NZ-FE ENGINE

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2. Construction The configuration of the engine control system in the 1NZ-FE engine is shown in the following chart. SENSORS VG

MASS AIR FLOW METER #10 #20

NE CRANKSHAFT POSITION #30 SENSOR #40

G2 CAMSHAFT POSITION SENSOR IGT1~ IGT4

VTA

THROTTLE POSITION SENSOR IGF

THW

ENGINE COOLANT TEMP. SENSOR THA

INTAKE AIR TEMP. SENSOR OCV

• Starting Signal (ST Terminal)

STA IGNITION SWITCH ECM

SPD

RSD COMBINATION METER

• Vehicle Speed Signal OX1A

HEATED OXYGEN SENSOR (Bank 1, Sensor FC 1) OX1B

HEATED OXYGEN SENSOR (Bank 1, Sensor 2) KNK1

KNOCK SENSOR HT

PSP

POWER STEERINGHT2 OIL*1 PRESSURE SWITCH ACTUATORS SFI No. 1 INJECTOR No. 2 INJECTOR 2000 ECHO (NCF 171U)

(Continued)

38 No. 3 INJECTOR No. 4 INJECTOR

ESA IGNITION COIL with IGNITER

SPARK PLUGS

VVT-i CAMSHAFT TIMING OIL CONTROL VALVE

IAC CONTROL VALVE

FUEL PUMP CONTROL CIRCUIT OPENING RELAY

OXYGEN SENSOR HEATER CONTROL HEATED OXYGEN SENSOR HEATER Bank 1, Sensor 1 Bank 1, Sensor 2

2000 ECHO (NCF 171U)

ENGINE — 1NZ-FE ENGINE

AC CONDITIONING AIR AMPLIFIER*2 ACT

PARK/NEUTRAL POSITION NSW SWITCH*3 • Neutral Start Signal • Shift Lever Position Signal

R,D,2,L

EVP1 CCV

PTNK

ECM

VAPOR PRESSURE SENSOR

STP

CF STOP LIGHT SWITCH

HOT, COOL

SIL

DATA TCLINK CONNECTOR 3

ALT

W

GENERATOR

AIR CONDITIONING CUT-OFF CONTROL*2 +B

BATT

AIR CONDITIONING BATTERY AMPLIFIER EFI MAIN RELAY

EVAP CONTROL *1: with Power Steering *2: with Air Conditioning VSV (for EVAP) *3: Only for Automatic Transaxle Model VSV (for CANISTER CLOSED VALVE)

COOLING FAN CONTROL COOLING FAN RELAY

ENGINE COOLANT TEMP. INDICATORS 2000 ECHO (NCF 171U)

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40 MALFUNCTION INDICATOR LAMP

2000 ECHO (NCF 171U)

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ENGINE — 1NZ-FE ENGINE

3. Engine Control System Diagram Park/Neutral Position Malfunction Switch*2 Indicator Ignition Lamp DLC3 Switch Generator Meter (Vehicle Speed Signal) A/C Amplifier*1 or A/C Switch*1

ECM

Power Steering Oil Pressure Sensor*3 Electric Load Switch

Circuit Opening Relay

Throttle Position Sensor

Battery

Mass Air Flow Meter (Built-in Intake Air Temp. Sensor)

IAC Valve VSV (for EVAP) Injector

Igniter Camshaft Position Sensor

VSV (for Canister Closed Valve)

Charcoal Canister

Engine Coolant Temp. Sensor

Camshaft Timing Oil Control Valve

Fuel Pump

Knock Sensor

Vapor Pressure Sensor

Crankshaft Position Sensor

TWC

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

*1: with Air Conditioning *2: Only for Automatic Transaxle Model *3: with Power Steering 171EG28

2000 ECHO (NCF 171U)

2000 ECHO (NCF 171U)

Crankshaft Position Sensor

Knock Sensor

Camshaft Timing Oil Control Valve

ECM

DLC3 Heated Oxygen Sensor (Bank 1, Sensor 2) Heated Oxygen Sensor (Bank 1, Sensor 1)

Water Temperature Sensor

Throttle Position Sensor IAC Valve

Mass Air Flow Meter Camshaft Position Sensor

VSV (for EVAP)

Vapor Pressure Sensor

VSV (for Canister Closed Valve)

42 ENGINE — 1NZ-FE ENGINE

4. Layout of Components

171EG39

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ENGINE — 1NZ-FE ENGINE

5. Main Components of Engine Control System The main components of the 1NZ-FE engine control system are as follows: Components Mass Air Flow Meter Crankshaft Position Sensor (Rotor’s Teeth)

Outline Hot-Wire Type Pick-Up Coil Type (36-2)

Quantity 1 1

Camshaft Position Sensor (Rotor’s Teeth) Throttle Position Sensor

Pick-Up Coil Type (3) Linear Type

1 1

Built-In Piezoelectric Element Type Heated Oxygen Sensor (Bank 1, Sensor 1) (Bank 1, Sensor 2)

1

12-Hole Type Rotary Solenoid Type (1-Coil Type)

4

Knock Sensor Oxygen Sensor Injector IAC Valve

2

1

6. VVT-i (Variable Valve Timing-intelligent) System General The VVT-i system is designed to control the intake camshaft within a wide range of 60° (of crankshaft angle) to provide a valve timing that is optimally suited to the engine condition, thus realizing improved torque in all the speed ranges and fuel economy, and reduce exhaust emissions.

VVT-i Controller

ECM Camshaft Position Sensor

Crankshaft Position Sensor

Camshaft Timing Oil Control Valve

2000 ECHO (NCF 171U)

171EG30

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ENGINE — 1NZ-FE ENGINE Construction 1) VVT-i Controller This controller consists of the housing driven from the timing chain and the vane coupled with the intake camshaft. The oil pressure sent from the advance or retard side path at the intake camshaft causes rotation in the VVT-i controller vane circumferential direction to vary the intake valve timing continuously. When the engine is stopped, the intake camshaft will be in the most retarded state to ensure startability. When hydraulic pressure is not applied to the VVT-i controller immediately after the engine has been started, the lock up pin locks the movement of the VVT-i controller to prevent a knocking noise. Vane (Fixed on Intake Camshaft)

Lock Pin

Intake Camshaft

171EG31

Housing Oil Pressure At a Stop

In Operation

Lock Pin 169EG36

2) Camshaft Timing Oil Control Valve The camshaft timing oil control valve controls the To VVT-i Controller spool valve position in accordance with the duty (Advanced Side)(Retard Side) control from the ECM thus allocating the hydrau- Sleeve Spool Valve lic pressure that is applied to the VVT-i controller to the advance and the retard side. When the engine is stopped, the camshaft timing oil control valve is in the most retarded state. Spring Drain

2000 ECHO (NCF 171U)

Drain Oil Pressure

Coil

Plunger 165EG34

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ENGINE — 1NZ-FE ENGINE Operation

The camshaft timing oil control valve selects the path to the VVT-i controller according to the advance, retard or hold signal from the ECM. The VVT-i controller rotates the intake camshaft in the timing advance or retard position or holds it according to the position where the oil pressure is applied. Camshaft Timing Oil Control Valve Drive Signal

Advance

Operation

Rotating Direction

Vane (Fixed on intake camshaft) VVT-i Controller Housing ECM

Description

Advance Signal When the camshaft timing oil control valve is positioned as illustrated at left by the advance signal from the ECM, the resultant oil pressure is applied to the timing advance side vane chamber to rotate the camshaft in the timing advance direction.

Duty Ratio Oil Pressure

157EG35

171EG36

Retard

Retard Signal

Rotating Direction

When the camshaft timing oil control valve is positioned as illustrated at left by the retard signal from the ECM, the resultant oil pressure is applied to the timing retard side vane chamber to rotate the camshaft in the timing retard direction.

ECM Duty Ratio Oil Pressure

157EG36

171EG37

Hold

Hold Signal

ECM

Duty Ratio Oil Pressure 171EG38

2000 ECHO (NCF 171U)

157EG37

The ECM calculates the target timing angle according to the traveling state to perform control as described above. After setting at the target timing, the valve timing is held by keeping the camshaft timing oil control valve in the neutral position unless the traveling state changes. This adjusts the valve timing at the desired target position and prevents the engine oil from running out when it is unnecessary.

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ENGINE — 1NZ-FE ENGINE In proportion to the engine speed, intake air volume, throttle position and water temperature, the ECM calculates an optimal valve timing under each driving condition and control the camshaft timing oil control valve. In addition, ECM uses signal from the camshaft position sensor and the crankshaft position sensor to detect the actual valve timing, thus performing feedback control to achieve the target valve timing. " Operation During Various Driving Condition (Conceptual Diagram) A

Engine Load

Full Load Performance

Range 5 Range 4 Range 3 Range 2

Range 1 Engine Speed Operation State

Range

165EG38

Valve Timing

Objective

TDC

During idling

1

At light load

2

At medium load In low to medium speed range with heavy load In high speed range with heavy load

3

4

5

Eliminating overlap to reduce blow back to the intake side Latest timing IN

EX

IN EX

To retard side

IN EX

To advance side To advance side

Stabilized idling rpm Better fuel economy

Decreasing overlap to eliminate blow back to the intake side

Ensured engine stability

Increasing overlap to increase internal EGR for pumping loss elimination

Better fuel economy Improved emission control

IN

Advancing the intake valve close timing for volumetric BDC efficiency improvement

IN

Retarding the intake valve

EX

Effect

Improved torque in low to medium speed range

EX

To retard side close timing for volumetric

Improved output

Stabilized fast idle rpm Better fuel economy

Improved startability

efficiency improvement

At low temperatures

—

EX

Eliminating overlap to prevent blow back to the intake IN side for reduction of fuel inLatest timing crease at low temperatures, and stabilizing the idling rpm for decreasing fast idle rotation

Upon starting/ stopping the engine

—

EX

Eliminating overlap to elimiLatest timing nate blow back to the intake side IN

2000 ECHO (NCF 171U)

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ENGINE — 1NZ-FE ENGINE

7. Evaporative Emission Control A vacuum method for detecting a leakage in the evaporative emission control system has been adopted. This method forcefully introduces the purge vacuum into the entire evaporative system and monitors the changes in the pressure. The main characteristics of the vacuum method are described below. D A VSV (for Canister Closed Valve) has been provided between the fresh air valve and the charcoal canister. D A vapor pressure sensor has been provided in the fuel tank in order to further ensure the precision of the vapor pressure sensor. D The fresh air valve characteristics of the charcoal canister have been changed. D DTCs (Diagnostic Trouble Codes) have been added. For details on the DTCs (Diagnostic Trouble Codes), refer to the 2000 ECHO Repair Manual (Pub. No. RM750U).

ECM

Vapor Pressure Sensor

Fuel Tank

VSV (for EVAP)

Charcoal Canister

To Air Intake Chamber From Air Cleaner

VSV (for Canister Closed Valve) 171EG25

8. Diagnosis System The diagnostic trouble codes can be output via DLC3 to an OBD-II scan tool or a hand-held tester. For details, refer to the 2000 ECHO Repair Manual (Pub. No. RM750U).

2000 ECHO (NCF 171U)