ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-33

JENGINE CONTROL SYSTEM

1. General
The engine control system of the 1TR-FE and 2TR-FE engines has the following system.

System Outline
D An L-type EFI system directly detects the intake air mass with a hot wire
type air flow meter.
D The fuel injection system is a sequential multiport fuel injection system.
D Fuel injection takes two forms:
Synchronous injection, which always takes place with the same timing in
EFI
! Electric Fuel accordance with the basic injection duration and an additional correction
EG
#
" "
based on the signals provided by the sensors.
# Injection !
Non-synchronous injection, which takes place at the time an injection
request based on the signals provided by the sensors is detected, regardless
of the crankshaft position.
D Synchronous injection is further divided into group injection during a cold
start, and independent injection after the engine is started.
D Ignition timing is determined by the ECM based on signals from various
ESA sensors. The ECM corrects ignition timing in response to engine knocking.
! Electric Spark #
D This system selects the optimal ignition timing in accordance with the
" "
# Advance ! signals received from the sensors and sends the (IGT) ignition signal to the
igniter.
ETCS-i
Electronic
! #
" "
Optimally controls the throttle valve opening in accordance with the amount
Throttle Control
of accelerator pedal effort and the condition of the engine and the vehicle.
" "
System-intelligent
# !

(See Page EG-49)

VVT-i
" Variable Valve Controls the intake camshaft to an optimal valve timing in accordance with
! #
"
# Timing-intelligent !
the engine condition.
(See Page EG-54)
Air Injection
The ECM controls the air injection time based on the signals from the air flow
System Control*1
meter and water temperature sensor.
(See Page EG-58)
Fuel pump operation is controlled by signals from the ECM.
Fuel Pump Control
Stops the fuel pump when the SRS airbag is deployed at the front or side
(See Page EG-63)
collision.*2
Air-fuel Ratio
Maintains the temperature of the air-fuel ratio sensor or heated oxygen sensor
Sensor*1, Heated
at an appropriate level to increase accuracy of detection of the oxygen
Oxygen Sensor*3
concentration in the exhaust gas.
Heater Control
Air Conditioning By turning the air conditioning compressor ON or OFF in accordance with the
Cut-off Control*4 engine condition, driveability is maintained.
Evaporative
The ECM controls the purge flow of evaporative emission (HC) in the
Emission
charcoal canister in accordance with engine conditions.
Control*3
(Continued)
*1: Models compliant with EURO III, EURO IV, BR-LEV and Tier 1 emission regulations
*2 :Models with SRS airbag system
*3: Models with unleaded gasoline engine
*4: Models with air conditioning system
EG-34 ENGINE – 1TR-FE AND 2TR-FE ENGINES

System Outline
Engine Prohibits fuel delivery and ignition if an attempt is made to start the engine with
Immobilizer* an invalid ignition key.
Diagnosis When the ECM detects a malfunction, the ECM diagnoses and memorizes the
(See Page EG-64) failed section.
Fail-safe When the ECM detects a malfunction, the ECM stops or controls the engine
(See Page EG-64) according to the data already stored in the memory.
*: Models with engine immobilizer system
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-35

2. Construction
The configuration of the engine control system in the 1TR-FE and 2TR-FE engines is as shown in the
following chart.
SENSORS ACTUATORS
VG
AIR FLOW METER EFI
#10
THA NO. 1 FUEL INJECTOR
INTAKE AIR TEMP. SENSOR #20
NO. 2 FUEL INJECTOR
#30
THW NO. 3 FUEL INJECTOR
WATER TEMP. SENSOR #40
NO. 4 FUEL INJECTOR

ACCELERATOR PEDAL VPA EG

POSITION SENSOR VPA2
IGT1 –
ESA
IGT4
VTA1 IGNITION COIL
THROTTLE POSITION SENSOR
VTA2 with IGNITER
IGF1
CRANKSHAFT POSITION NE
SPARK PLUGS
SENSOR

G2 VVT-i
CAMSHAFT POSITION SENSOR
OC1 CAMSHAFT TIMING OIL
AIR-FUEL RATIO SENSOR*1 A1A CONTROL VALVE
(Bank 1, Sensor 1)
ECM ETCS-i
HEATED OXYGEN SENSOR*2 OX1A
(Bank 1, Sensor 1) M THROTTLE CONTROL
MOTOR

HEATED OXYGEN SENSOR*1 OX1B

(Bank 1, Sensor 2) HEATED OXYGEN SENSOR
AND AIR-FUEL RATIO SENSOR
HEATER CONTROL
VAF
VARIABLE RESISTOR*3 HEATER
HA1A*1
(Bank 1, Sensor 1)
KNK1 HT1A*2
KNOCK SENSOR (Bank 1, Sensor 2)
HT1B*1

IGNITION SWITCH FUEL PUMP CONTROL

STA
D Starting Signal IGSW FC
D Ignition Signal CIRCUIT OPENING RELAY

NSW
NEUTRAL START SWITCH*4 AIR INJECTION CONTROL*1
R, 2, L
AIRP
AIR INJECTION
SHIFT LOCK ECU*4 AIRV
DRIVER
AIDI
TRANSMISSION 3
ELECTRIC AIR
CONTROL SWITCH PUMP

ALT AIR SWITCHING

ALTERNATOR VALVE
271EG40

(Continued)
EG-36 ENGINE – 1TR-FE AND 2TR-FE ENGINES

PSW
POWER STEERING EVAPORATIVE EMISSION
OIL PRESSURE SWITCH CONTROL*9
PRG
ELS VSV (for EVAP)
TAILLIGHT RELAY

REAR WINDOW ELS3

DEFOGGER RELAY*5
AIR CONDITIONING
TFN
TRANSFER NEUTRAL SWITCH*6
AMPLIFIER*10
AC1
Idle-up Request Signal
L4
L4 POSITION SWITCH*6 ACT Magnetic Clutch
Actuation Signal
ECM
4WD
4WD CONTROL ECU*6

IMI MREL
+B EFI MAIN RELAY
TRANSPONDER KEY ECU*7 IMO

STP
STOP LIGHT SWITCH
ST1–

F/PS
AIRBAG SENSOR ASSEMBLY*8 COMBINATION METER
TC SPD
Vehicle Speed Signal
SIL TACH
DLC 3 WFSE
Tachometer
THWO
TACH Water Temperature Signal
W
BATT Check Engine Warning Light
BATTERY

00LEG100I

*1: Models compliant with EURO III, EURO IV, BR-LEV and Tier 1 emission regulations
*2: Models compliant with EURO II emission regulations
*3: Models with leaded gasoline engine
*4: Models with automatic transmission
*5: Models with rear window defogger
*6: 4WD models
*7: Models with engine immobilizer system
*8: Models with SRS airbag system
*9: Models with unleaded gasoline engine
*10:Models with air conditioning system
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-37

3. Engine Control System Diagram

" Models with Leaded Gasoline Engine A

A/C Magnetic A/C

Clutch Amplifier*1 Check Engine
Vehicle Combination
Warning Light
Speed Signal Meter

Neutral Start Switch*2 Accelerator Pedal

Power Steering Position Sensor
Oil Pressure Switch Ignition Switch Battery
Variable Resistor EG
ECM
Alternator
Circuit Opening Relay
DLC3
Fuel
Ignition Coil Pump
with Igniter

Camshaft
Position
Sensor
Camshaft
Throttle
Timing Oil Position
Control Valve Sensor

Throttle
Control Motor

Fuel
Injector
Air Flow Meter
D Intake Air Temperature Sensor
Knock Sensor

00LEG01
Crankshaft Position
Sensor

Water Temperature Sensor

*1: Models with air conditioning system

*2: Models with automatic transmission
EG-38 ENGINE – 1TR-FE AND 2TR-FE ENGINES

" Models Compliant EURO II Emission Regulations A

A/C Magnetic A/C

Clutch Amplifier*1 Check Engine
Vehicle Warning Light
Combination
Speed Signal Meter

Neutral Start Switch*2 Accelerator Pedal

Power Steering Position Sensor
Oil Pressure Switch Ignition Switch
Battery

Alternator ECM

Circuit Opening Relay

DLC3
VSV
(for EVAP)
Ignition Coil Fuel
with Igniter Pump

Camshaft
Position
Sensor
Throttle
Camshaft Position
Timing Oil Sensor
Control Valve

Throttle
Control Motor

Fuel
Injector
Air Flow Meter
D Intake Air Temperature Sensor
Knock Sensor
Heated Oxygen Sensor
(Bank 1, Sensor 1)

Crankshaft Position 00LEG05

Sensor

Water Temperature Sensor

*1: Models with air conditioning system

*2: Models with automatic transmission
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-39

" Models Compliant EURO III, EURO IV, BR-LEV and Tier 1 Emission Regulations A

A/C Magnetic A/C

Clutch Amplifier*1 Check Engine
Vehicle Combination
Warning Light
Speed Signal Meter

Neutral Start Switch*2

Accelerator Pedal
Power Steering Position Sensor
Oil Pressure Switch Battery
Ignition Switch

Alternator ECM
EG
Circuit Opening Relay
DLC3
VSV
(for EVAP)
Ignition Coil Fuel
with Igniter Pump
Camshaft
Position
Sensor
Camshaft Throttle
Timing Oil Position
Air Injection Control Valve
Sensor
Driver
Electric
Air Pump
Throttle
Control Motor

Fuel
Injector
Air Flow Meter
D Intake Air Temperature Sensor
Air Switching Knock Sensor
Valve

00LEG06

Crankshaft Position
Heated Oxygen Sensor Sensor
(Bank 1, Sensor 2) Water Temperature Sensor

Air-fuel Ratio Sensor

(Bank 1, Sensor 1)

*1: Models with air conditioning system

*2: Models with automatic transmission
EG-40 ENGINE – 1TR-FE AND 2TR-FE ENGINES

4. Layout of Main Components

Air Injection Driver*1 VSV (for EVAP)*3

Variable Resistor*2

Air Flow Meter

Throttle Body
Ignition Coil D Throttle Position Sensor
with Igniter D Throttle Control Motor
Fuel
Injector
Camshaft D Heated Air-fuel Ratio Sensor*1
Position Sensor (Bank 1, Sensor 1)
D Heated Oxygen Sensor*4
(Bank 1, Sensor 1)
Heated Oxygen Sensor*1
Water Temperature (Bank 1, Sensor 2)
Sensor

Check Engine
Warning Light
Knock
Sensor
ECM

Crankshaft
Position Sensor

Camshaft Timing
Oil Control Valve Stop Light Switch

DLC3

00LEG52Y

Accelerator Pedal
Position Sensor
LHD Models

*1: Models compliant EURO III, EURO IV, BR-LEV and Tier 1 emission regulations
*2: Models with leaded gasoline engine
*3: Models with unleaded gasoline engine
*4: Models compliant EURO II emission regulations
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-41

5. Main Components of Engine Control System

General
The main components of the 1TR-FE and 2TR-FE engine control system are as follows:
Components Outline Quantity Function
The ECM optimally controls the EFI, ESA,
and ISC to suit the operating conditions of
ECM 32-bit CPU 1
the engine in accordance with the signals
provided by the sensors.
Heated Oxygen
Planar Type
Sensor 1 This sensor detects the oxygen
with Heater
(Bank 1, Sensor 1)*1 concentration in the exhaust emission by EG
Heated Oxygen measuring the electromotive force which is
Cup Type generated in the sensor itself.
Sensor 1
with Heater
(Bank 1, Sensor 2)*2
As with the heated oxygen sensor, this
Air-fuel sensor detects the oxygen concentration in
Planar Type
Ratio Sensor 1 the exhaust emission. However, it detects
with Heater
(Bank 1, Sensor 1)*2 the oxygen concentration in the exhaust
emission linearly.
This sensor has a built-in hot-wire to
Air Flow Meter Hot-wire Type 1
directly detect the intake air volume.
Crankshaft
Pick-up Coil Type This sensor detects the engine speed and
Position Sensor 1
(36-2) performs the cylinder identification.
(Rotor Teeth)
Camshaft
Pick-up Coil Type This sensor performs the cylinder
Position Sensor 1
(3) identification.
(Rotor Teeth)
Water Temperature This sensor detects the water temperature
Thermistor Type 1
Sensor by means of an internal thermistor.
This sensor detects the intake air
Intake Air
Thermistor Type 1 temperature by means of an internal
Temperature Sensor
thermistor.
This sensor detects an occurrence of the
Built-in
engine knocking indirectly from the
Knock Sensor Piezoelectric Type 1
vibration of the cylinder block caused by
(Flat Type)
the occurrence of engine knocking.
Throttle This sensor detects the throttle valve
Non-contact Type 1
Position Sensor opening angle.
Accelerator Pedal This sensor detects the amount of pedal
Non-contact Type 1
Position Sensor effort applied to the accelerator pedal.
The fuel injector is an
12-hole Type*3 electromagnetically-operated nozzle which
Fuel Injector 4
4-hole Type*4 injects fuel in accordance with signals from
the ECM.
This is a variable resistor to adjust the
air-fuel ratio while the engine is idling. The
Variable Resistor*4 Variable Resistor 1
idle CO value is adjusted to the specified
value by rotating the rotor.
*1: Models compliant EURO II emission regulations
*2: Models compliant EURO III, EURO IV, BR-LEV and Tier 1 emission regulations
*3: Models with unleaded gasoline engine
*4: Models with leaded gasoline engine
EG-42 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Air-fuel Ratio Sensor and Heated Oxygen Sensor

1) General
D The air-fuel ratio sensor and heated oxygen sensor differ in output characteristics.
D Approximately 0.4 V is constantly applied to the air-fuel ratio sensor, which outputs an amperage that
varies in accordance with the oxygen concentration in the exhaust emission. The ECM converts the
changes in the output amperage into voltage in order to linearly detect the present air-fuel ratio. The
air-fuel ratio sensor data is read out by an intelligent tester II.
D The output voltage of the heated oxygen sensor changes in accordance with the oxygen concentration
in the exhaust emission. The ECM uses this output voltage to determine whether the present air-fuel
ratio is richer or leaner than the stoichiometric air-fuel ratio.

A1A+ OX1B
(3.3 V)
Heated
Air-fuel Oxygen
Ratio Sensor ECM Sensor ECM

A1A– EX1B
(2.9 V)

00REG21Y

Air-fuel Ratio Sensor Circuit Heated Oxygen Sensor Circuit

: Air-fuel Ratio Sensor

: Heated Oxygen Sensor
4.2 1

Air-fuel Ratio Sensor Data Heated Oxygen

Displayed on Intelligent Sensor Output (V)
Tester II

2.2 0.1

11 (Rich) 14.7 19 (Lean)

D13N11
Air-fuel Ratio
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-43

2) Construction
D The basic construction of the air-fuel ratio sensor and heated oxygen sensor is the same. However, they
are divided into the cup type and the planar type, according to the different types of heater construction
that are used.
D The cup type sensor contains a sensor element that surrounds a heater.
D The planar type sensor uses alumina, which excels in heat conductivity and insulation, to integrate a
sensor element with a heater, thus realizing the excellent warm-up performance of the sensor.

EG
Platinum Heater
Alumina Electrode
Atmosphere
Dilation Layer Atmosphere
Alumina

Heater
Platinum
Electrode Sensor Element
(Zirconia)
Sensor Element (Zirconia) 047EG68Y

Planar Type Air-fuel Ratio Sensor Cup Type Heated Oxygen Sensor

" Warm-up Specification A

Sensor Type Planar Type Cup Type

Warm-up Time Approx. 10 sec. Approx. 30 sec.

Air Flow Meter

D The compact and lightweight 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
high detection precision is achieved and the intake air resistance is reduced.
D This air flow meter has a built-in intake air temperature sensor.

Temperature Sensing
Element

Air Flow
Platinum Hot-wire Intake Air
Element Temperature Sensor

204EG54
EG-44 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Crankshaft and Camshaft Position Sensors

D 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.
D To detect the camshaft position, a timing rotor on the intake camshaft is used to generate 3 pulses for every
2 revolutions of the crankshaft.

Crankshaft
Position Sensor

Camshaft
Position Sensor
Timing Rotor Timing Rotor
271EG46 271EG47

Crankshaft Position Sensor Camshaft Position Sensor

" Sensor Output Waveforms A

720_ CA

180_ CA 180_ CA 360_ CA

2 Teeth Missing

2 Teeth Missing
10_ CA
DR017EG24
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-45

Knock Sensor (Flat Type)

1) General
In the conventional type knock sensor (resonant type), a vibration plate which has the same resonance
point as the knocking frequency of the engine is built in and can detect the vibration in this frequency
band.
On the other hand, a flat type knock sensor (non-resonant type) has the ability to detect vibration in a
wider frequency band from about 6 kHz to 15 kHz, and has the following feature.
D The engine knocking frequency will change a little depending on the engine speed. The flat type knock
sensor can detect the vibration even when the engine knocking frequency is changed. Thus the
vibration detection ability is increased compared to the conventional type knock sensor, and more
precise ignition timing control is possible. EG

: Resonance Characteristic of Conventional Type

: Resonance Characteristic of Flat Type

(V)
A: Detection Band of
A
Conventional Type

B: Detection Band of
Voltage Flat Type

Frequency (Hz)

Characteristic of Knock Sensor 214CE04

2) Construction
D The flat type knock sensor is installed on the engine through the stud bolt installed on the cylinder
block. For this reason, a hole for the stud bolt runs through the center of the sensor.
D Inside of the sensor, a steel weight is located on the upper portion and a piezoelectric element is located
under the weight through the insulator.
D The open/short circuit detection resistor is integrated.

Open/Short Circuit
Steel Weight Detection Resistor
Piezoelectric
Element
Insulator
Vibration Plate
Piezoelectric
Element

Flat Type Knock Sensor Conventional Type Knock Sensor

(Non-resonant Type) (Resonant Type)
214CE01 214CE02
EG-46 ENGINE – 1TR-FE AND 2TR-FE ENGINES

3) Operation
The knocking vibration is transmitted to the
steel weight and its inertia applies pressure to
the piezoelectric element. The action Steel Weight
generates electromotive force. Inertia

Piezoelectric
Element
214CE08
4) Open/Short Circuit Detection Resistor
While the ignition is ON, the open/short circuit detection resistor in the knock sensor and the resistor
in the ECM keep the voltage at terminal KNK1 of ECM of the engine constant.
An IC (Integrated Circuit) in the ECM is always monitoring the voltage of terminal KNK1. If the
open/short circuit occurs between the knock sensor and the ECM, the voltage of terminal KNK1 will
change and the ECM will detect the open/short circuit and store DTC (Diagnostic Trouble Code).

ECM

Piezoelectric
Element 5V
Flat Type Knock Sensor
220 k!
KNK1
IC
200 k!
EKNK

Open/Short Circuit 214CE06

Detection Resistor

Service Tip
D In accordance with the use of an open/short circuit detection resistor, the inspection method
for the sensor has been changed. For details, refer to the Hilux Repair Manual.
D To prevent water accumulation in the connecter, make sure to install the flat type knock sensor
in the position shown in the following illustration.

Knock Sensor

10_
10_

271EG03
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-47

Throttle Position Sensor

The throttle position sensor is mounted on the throttle body, to detect the opening angle of the throttle valve.
The throttle position sensor converts the magnetic flux density that changes when the magnetic yoke
(located on the same axis as the throttle shaft) rotates around the Hall IC into electric signals that operate
the throttle control motor.

Throttle Body

Throttle Position
Sensor Portion Magnetic
Yoke
EG
Hall IC

Magnetic
Yoke

271EG48
Cross Section

Throttle Position
Sensor
V
Magnetic Yoke 5
VTA2
VTA1
Output
Hall E2 Voltage VTA1
IC

Hall VC ECM
IC
VTA2 0
90_
Throttle Throttle
Valve Valve
Fully Closed Fully Open
Throttle Valve Opening Angle
230LX12 082EG14Y

Service Tip
The inspection method differs from the conventional throttle position sensor because this sensor
uses a Hall IC. For details, refer to the Hilux Repair Manual.
EG-48 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Accelerator Pedal Position Sensor

The magnetic yoke that is mounted at the base of the accelerator pedal arm rotates around the Hall IC in
accordance with the amount of effort that is applied to the accelerator pedal. The Hall IC converts the
changes in the magnetic flux that occur into electrical signals, and outputs them in the form of accelerator
pedal effort to the ECM.

Magnetic
Yoke
Hall IC

271EG49

Accelerator Pedal
Position Sensor
Magnet Yoke
VPA V
5
EPA
Hall VCPA VPA2
IC Output
VPA2 ECM Voltage
Hall
IC VPA
EPA2
0
VCP2
Accelerator Pedal
Fully Depressed Angle Fully
Close Open
228TU24 082EG12Y

Service Tip
The inspection method differs from the conventional accelerator pedal position sensor because this
sensor uses a Hall IC. For details, refer to the Hilux Repair Manual.
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-49

6. ETCS-i (Electronic Throttle Control System-i)

General
D The ETCS-i is used, providing excellent throttle control in all the operating ranges.
D The accelerator cable has been discontinued, and an accelerator pedal position sensor has been provided
on the accelerator pedal.
D In the conventional throttle body, the throttle valve opening is determined invariably by the amount of
accelerator pedal effort. In contrast, the ETCS-i uses the ECM to calculate the optimal throttle valve
opening that is appropriate for the respective driving condition and uses a throttle control motor to control
the opening.
D The ETCS-i controls the ISC (Idle Speed Control) system. EG
D In case of an abnormal condition, this system transfers to the limp mode.

" System Diagram A

Throttle Valve
Throttle Position Sensor

Accelerator Pedal
Position Sensor Throttle
Control
Motor

Air Flow ECM

Meter

Ignition Fuel
Coil Injector
237EG23
EG-50 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Construction

Throttle Body

Throttle Position
Sensor Portion
Reduction
Gears

View from A

Magnetic Yoke

Hall IC
(for Throttle Position Sensor)
Magnetic Yoke
Throttle Valve

Throttle Control
Motor
Cross Section 271EG50

1) Throttle Position Sensor

The throttle position sensor is mounted on the throttle body, to detect the opening angle of the throttle
valve.

2) Throttle Control Motor

A DC motor with excellent response and minimal power consumption is used for the throttle control
motor. The ECM performs the duty cycle control of the direction and the amperage of the current that
flows to the throttle control motor in order to regulate the opening of the throttle valve.
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-51

Operation

1) General
The ECM drives the throttle control motor by determining the target throttle valve opening in accordance
with the respective operating conditions as follows:
D Non-linear Control
D Idle Speed Control

2) Non-linear Control
Controls the throttle to an optimal throttle valve opening that is appropriate for driving conditions such EG
as the amount of the accelerator pedal effort and the engine speed in order to achieve excellent throttle
control and comfort in all operating ranges.

" Control Examples During Acceleration and Deceleration A

: With Control
: Without Control
"
Vehicle’s
Longitudinal G
0

"
Throttle Valve
Opening Angle
0
"
Ignition Timing
0
Time !
150EG37

3) Idle Speed Control

The ECM controls the throttle valve in order to constantly maintain an ideal idle speed.
EG-52 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Fail-safe of Accelerator Pedal Position Sensor

D The accelerator pedal position sensor is comprised of 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 and switches to the limp mode. In the limp mode, the remaining circuit
is used to calculate the accelerator pedal depressed angle, in order to operate the vehicle under limp mode
control.

ECM

Accelerator Pedal
Position Sensor Open

Main
Sub Main
Sub
Throttle
Throttle Return Control
Throttle Valve
Position Spring Motor
Sensor
Accelerator Pedal Throttle Body
199EG45

D If both circuits have a malfunction, the ECM detects the abnormal signal voltage from these two sensor
circuits and discontinues the throttle control. At this time, the vehicle can be driven within its idling
range.

ECM

Accelerator Pedal Close by Return

Position Sensor Spring

Main
Sub Main
Sub
Throttle Throttle
Throttle Valve Return
Position Control
Spring
Sensor Motor

Accelerator Pedal Throttle Body

199EG46
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-53

Fail-safe of Throttle Position Sensor

D The throttle position sensor is comprised of two (main, sub) sensor circuits. If a malfunction occurs in
either one or both 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
angle. 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 (intermittent fuel-cut) and ignition timing in accordance with the
accelerator opening.
D The same control as above is effected if the ECM detects a malfunction in the throttle control motor
system.
EG
Fuel Injectors ECM Ignition Coil

Accelerator Pedal Return to

Position Sensor Prescribed Angle

Main
Sub Main
Sub
Throttle
Throttle Return
Throttle Valve Control
Position Spring
Motor
Sensor
Accelerator Pedal Throttle Body
199EG47
EG-54 ENGINE – 1TR-FE AND 2TR-FE ENGINES

7. VVT-i (Variable Valve Timing-intelligent) System

General
D The VVT-i system is designed to control the intake camshaft within a range of 45_ (of crankshaft angle)
to provide valve timing that is optimally suited to the engine condition. This improves torque in all the
speed ranges as well as increasing fuel economy, and reducing exhaust emissions.

Camshaft Position Sensor

Camshaft Timing Oil Control Valve

Water Temperature
Sensor

Throttle Position
Sensor

ECM

Air Flow
Meter
Crankshaft Position Sensor

271EG51

D Using the engine speed, intake air volume, throttle position and water temperature, the ECM can
calculate optimal valve timing for each driving condition and controls the camshaft timing oil control
valve. In addition, the ECM uses signals from the camshaft position sensor and the crankshaft position
sensor to detect the actual valve timing, thus providing feedback control to achieve the target valve
timing.

ECM

Crankshaft Position Sensor Target Valve Timing Camshaft Timing

Oil Control Valve
Duty Cycle
Air Flow Meter Control
Throttle Position Sensor Feedback

Water Temperature Sensor Correction

Camshaft Position Sensor Actual Valve Timing

Vehicle Speed Signal

221EG16
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-55

Effectiveness of the VVT-i System

Operation State Objective Effect

TDC
Latest Timing
D Stabilized idling
Decreasing overlap to
EX IN speed
During Idling reduce blow back to
D Better fuel
the intake side
economy

BDC 271EG52

To Retard Side
EG
Decreasing overlap to
EX IN Ensured engine
At Light Load reduce blow back to
stability
the intake side
271EG53

To Advance Side
Increasing overlap to D Better fuel
increase internal EGR economy
At Medium Load EX IN
to reduce pumping D Improved
loss emission control
271EG54

Advancing the intake

In Low to Medium Improved torque
EX IN valve close timing for
Speed Range with in low to medium
volumetric efficiency
Heavy Load speed range
To Advance Side
improvement
271EG55

Retarding the intake

In High Speed
EX IN valve close timing for
Range with Improved output
volumetric efficiency
Heavy Load
improvement
To Retard Side 271EG95

Latest Timing Decreasing overlap to

reduce blow back to
D Stabilized fast
the intake side leads to
At Low EX IN idle speed
the lean burning
Temperatures D Better fuel
condition, and
economy
stabilizes the idling
271EG52
speed at fast idle
Latest Timing

D Upon Starting Decreasing overlap to Improved

D Stopping the EX IN reduce blow back to the
intake side startability
Engine
271EG52
EG-56 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Construction

1) VVT-i Controller
This controller consists of a housing driven by the timing chain and a 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 started, the lock
pin locks the movement of the VVT-i controller to prevent a knocking noise. Thereafter, when hydraulic
pressure is applied to the VVT-i controller, the lock pin is released.

Lock Pin
Housing

Timing
Rotor Intake Camshaft

Sprocket

Vane (Fixed on Intake Camshaft)

Oil Pressure

In Operation At a Stop

Lock Pin 271EG56

2) Camshaft Timing Oil Control Valve

This camshaft timing oil control valve controls the spool valve using duty cycle control from the ECM.
This allows hydraulic pressure to be applied to the VVT-i controller advance or retard side. When the
engine is stopped, the camshaft timing oil control valve is in the most retarded position.

To VVT-i Controller To VVT-i Controller

(Advance Side) (Retard Side)

Sleeve

Spring

Drain Drain Coil Plunger

Oil Pressure Spool Valve 238EG62
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-57

Operation

1) Advance
When the camshaft timing oil control valve is positioned as illustrated below by the advance signals 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.

Vane

ECM EG

Oil Pressure
Rotation Direction
In Drain
271EG57

2) Retard
When the camshaft timing oil control valve is positioned as illustrated below by the retard signals 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.

Rotation Direction

ECM

Oil Pressure
Vane
Drain In
271EG58

3) Hold
After reaching 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.
EG-58 ENGINE – 1TR-FE AND 2TR-FE ENGINES

8. Air Injection System

General
D This system uses an electric air pump for pumping air to the cylinder head. This ensures the proper
warm-up performance of the TWC during the cooled down engine state.
D This system consists of an electric air pump, an air injection control valve, and an air injection driver.

Air Injection
Driver
ECM

Air Injection
Control Valve

Electric Air Pump

271EG59
TWC
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-59

Layout of Main Components

ECM
(for LHD Model)
ECM
(for RHD Model)
Air Injection Driver
(for LHD Model)

Air Injection
Control Valve

EG

Air Injection Driver

(for RHD Model)

Electric Air Pump

Exhaust Manifold
00LEG53Y

Function of Main Components

Item Function
Electric Air Pump Uses a built-in DC motor to supply air to the air injection control valve.
Air Injection
Introduces air that is pumped by the electric air pump into the exhaust manifold.
Control Valve
D Activated by the ECM, the air injection driver actuates the electric air pump
Air Injection and the air injection control valve.
Driver D Detects an input-output circuit failure at the air injection driver and transmits
it to the ECM.
D Controls the air injection system in accordance with the signals (water
temperature and intake air volume) received from the sensors.
ECM
D Receives a failure detection signal from the air injection driver and stores a
corresponding DTC in memory.
EG-60 ENGINE – 1TR-FE AND 2TR-FE ENGINES

Construction and Operation

1) Electric Air Pump

D An electric air pump consists of a DC motor and an impeller.
D DC motor operation is controlled by the ECM via an air injection driver. The motor supplies air into
an air injection control valve through the impeller.

Impeller
From
Air Inlet

To Air Injection
Control Valve

DC Motor

271EG61

2) Air Injection Control Valve

D An air injection control valve consists of an air switching valve that switches the air flow and a reed
valve that restricts the exhaust flow to one direction.
D The air switching valve is a solenoid valve that is actuated by the air injection driver.
D When the air switching valve turns ON, an air injection pipe, which is provided in the exhaust
manifold, directs the air from the electric air pump to the exhaust port.

Air Injection Control Valve

Air
Injection Air Switching
Pipe Valve

To Air
Injection Pipe

From Electric
Exhaust Manifold Air Pump
Reed Valve
271EG62 271EG63

Air Injection Control Valve Cross Section

 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-61

3) Air Injection Driver

D The air injection driver is a non-contact type relay that uses semiconductors. Activated by the ECM,
this driver actuates the electric air pump and the air injection control valve.
D The air injection driver also detects failures in the input and output circuits at the air injection driver
and transmits the failure status to the ECM via duty cycle signals.

Electric Air Pump

Actuation Request
AIRP SIP
Electric Air Pump
VP
EG
Air Injection Control
ECM Valve Actuation Request Air Injection
Air Injection
AIRV SIV Driver
Control Valve
VV

Duty Cycle Signal

AIDI DI

271EG64

" DI Terminal Output A

Condition Duty Cycle (Duty Cycle Signal)

A 80%
Normal
B 0%
Open circuit in line between AIDI and DI terminals 100%
Failure in line between ECM terminals and air injection
A 0%
driver
Output failure at air injection driver
20%
(failure in electric air pump actuation circuit)
Output failure at air injection driver
40%
(failure in air injection control valve actuation circuit)
Overheat failure of air injection driver 60%

A: Electric air pump and air injection control valve actuation requests have been made
B: Conditions other than A
EG-62 ENGINE – 1TR-FE AND 2TR-FE ENGINES

System Operation
To effect this control during the cooled down engine state (water temperature: 15_C − 45_C*1 and 15_C
– 60_C*2), the ECM estimates the amount of air to the TWC based on the signals from the air flow meter
in order to regulate the air injection time (80 seconds maximum).
*1: Models compliant with EURO IV and BR-LEV emission regulations
*2: Except models compliant with EURO IV and BR-LEV emission regulations

Water
Temperature Air Injection
Sensor Driver

Air Flow ECM

Meter

Air Injection
Control Valve

Electric Air Pump

TWC 271EG65
 ENGINE – 1TR-FE AND 2TR-FE ENGINES EG-63

9. Fuel Pump Control

D A fuel cut control is used to stop the fuel pump once when the SRS airbag is deployed in the front or side*
collision.
D In this system, the airbag deployment signal from the airbag assembly is detected by the ECM, and it 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.

Curtain Shield Side Airbag

Airbag Sensor Sensor Assembly
(RH and LH)* EG
Assembly*

IG Switch EFI Main

Relay
Circuit
Front Airbag Airbag Opening
Sensors Sensor ECM Relay
(RH and LH) Assembly

Battery Fuel Pump

Airbag Voltage
Not Deployed
Motor
Battery
Airbag Voltage
Deployed
Approx. 4 sec.
00LEG54Y

*: Models with driver, front passenger, side and curtain shield airbags system
EG-64 ENGINE – 1TR-FE AND 2TR-FE ENGINES

10. Diagnosis
D The diagnosis system of the 1TR-FE and 2TR-FE engines uses the M-OBD (Multiplex On-Board
Diagnosis).
D When the ECM detects a malfunction, it makes a diagnosis and memorizes the failed section. Furthermore,
the check engine warning light in the combination meter illuminates or blinks to inform the driver of this.
D The 2-digit DTCs (Diagnostic Trouble Codes) can be accessed by connecting the SST (09843-18040) to
the DLC3 terminals TC and CG, and reading the blinking of the check engine warning light.
D By using the intelligent tester II, the 5-digit DTCs and ECM data can be read out. Moreover, the ACTIVE
TEST can be used to drive the actuator by means of the intelligent tester II.
D The ECM can output freeze-frame data to the intelligent tester II. This data is stored in the ECM at the very
moment when the ECM has detected its last data of malfunction.
D All the DTCs have been made to correspond to the SAE controlled codes. Some of the DTCs have been
further divided into smaller detection areas than in the past, and new DTCs have been assigned to them.
D For details, refer to the Hilux Repair Manual.

Service Tip
To clear the DTC that is stored in the ECM, use a intelligent tester II or disconnect the battery terminal
or remove the EFI fuse for 1 minute or longer.

11. Fail-safe
When a malfunction is detected by any of the sensors, there is a possibility of an engine or other malfunction
occurring if the ECM continues to control the engine control system in the normal way. To prevent such a
problem, the fail-safe function of the ECM either relies on the data stored in memory to allow the engine
control system to continue operating, or stops the engine if a hazard is anticipated. For details, refer to the
Hilux Repair Manual.