Page 113 of 2000

ENGINE - 2GR-FE ENGINE
238EG70
Synchronous Injection
IgnitionNon-synchronous Injection
Crankshaft Angle # 1
# 2
# 3
# 4
# 5
# 6
0
120240360480600720
Independent InjectionEG-117
Air-fuel Ratio Sensor and Heated Oxygen Sensor
The planar type air-fuel ratio sensor and the cup type heated oxygen sensor are used. For details, see page
EG-37.
6. SFI (Sequential Multiport 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) is used.
There are two (synchronous and non-synchronous) injections:
a) The synchronous injection in which corrections based on the signals from the sensors are added to the
basic injection time so that injection occurs always at the same position.
b) The 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 achieve lower fuel consumption, the system uses a fuel cutoff in
which the injection of fuel is stopped temporarily in accordance with the driving conditions.
This system performs group injection when the engine coolant temperature is extremely low and the
engine is operating at a low speed.
7. ESA (Electronic Spark Advance) System
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.
Page 114 of 2000
ENGINE - 2GR-FE ENGINE
01MEG18Y
Accelerator Pedal
Position SensorThrottle ValveThrottle Position Sensor
Throttle Control
Motor
Mass Air
Flow Meter
Cruise Control
Switch
Skid Control
ECUECMIgnition Coil
Fuel Injection EG-118
8. ETCS-i (Electronic Throttle Control System-intelligent)
General
In the conventional throttle body, the throttle valve angle is determined invariably by the amount of the
accelerator pedal effort. In contrast, ETCS-i uses the ECM to calculate the optimal throttle valve angle that
is appropriate for the respective driving condition and uses a throttle control motor to control the angle.
System Diagram
Control
1) General
The ETCS-i consists of the following five functions:
Normal Throttle Control (Non-linear Control)
IAC (Idle Air Control)
TRAC (Traction Control)
VSC (Vehicle Stability Control)
Cruise Control
Page 115 of 2000

ENGINE - 2GR-FE ENGINE
005EG13Y
: With Control
: Without Control
Ve h i c l e ’ s
Longitudinal G
Throttle Valve
Opening Angle
Accelerator Pedal
Depressed Angle
0
0
0
Time
EG-119
2) Normal Throttle Control (Non-linear Control)
The ECM controls the throttle to an optimal throttle valve angle that is appropriate for the driving
condition such as the amount of the accelerator pedal effort and the engine speed in order to realize
excellent throttle control and comfort in all operating ranges.
Control Examples during Acceleration and Deceleration
3) Idle Air Control
The ECM controls the throttle valve in order to constantly maintain an ideal idle speed.
4) TRAC Throttle Control
As part of the TRAC system, the throttle valve is closed by a demand signal from the skid control ECU
if an excessive amount of slippage is created at a driving wheel, thus facilitates the vehicle in ensuring
excellent vehicle stability and driving force.
5) VSC Coordination Control
In order to bring the effectiveness of the VSC system control into full play, the throttle valve angle is
controlled by effecting a coordination control with the skid control ECU.
6) Cruise Control
An ECM with an integrated cruise control ECU directly actuates the throttle valve for operation of the
cruise control.
Fail-safe of Accelerator Pedal Position Sensor
For details, see page 46 in 2AZ-FE engine section.
Fail-safe of Throttle Position Sensor
For details, see page 47 in 2AZ-FE engine section.
Page 116 of 2000

ENGINE - 2GR-FE ENGINE
285EG57
Exhaust Camshaft Timing OCV* (Bank 1)
Intake Camshaft Timing OCV* (Bank 1)
Exhaust VVT Sensor (Bank 1)
Engine Coolant Temperature Sensor
Intake Camshaft
Timing OCV* (Bank 2)
Exhaust VVT
Sensor (Bank 2)
Exhaust Camshaft
Timing OCV*
(Bank 2)
Intake VVT Sensor (Bank 2)
Crankshaft Position Sensor
Intake VVT Sensor (Bank 1)ECM
Mass Air Flow MeterThrottle Position Sensor
221EG16
Crankshaft Position Sensor
Mass Air Flow Meter
Throttle Position Sensor
Engine Coolant Temp. Sensor
Intake and Exhaust VVT Sensors
Vehicle Speed SignalECM
Ta r g e t Va l v e Ti m i n g
Feedback
Correction
Actual Valve Timing
Duty-cycle
Control
Camshaft Timing
Oil Control Valve
EG-120
9. Dual VVT-i (Variable Valve Timing-intelligent) System
General
The Dual VVT-i system is designed to control the intake and exhaust camshafts within a range of 40
and 35 respectively (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.
*: Oil Control Valve
Using the engine speed signal, vehicle speed signal, and the signals from mass air flow meter, throttle
position sensor and engine coolant temperature sensor, the ECM calculates 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.
Page 124 of 2000

ENGINE - 2GR-FE ENGINE
01MEG19Y
VSV
Air Cleaner Cap
Vacuum Tank
Actuator
ECM
Air Intake Control Valve
01MEG20Y
Engine
Speed
SignalECMThrottle Position Sensor Signal
VSVVacuum TankIntake Air
Chamber
Air Cleaner Element
Actuator
Air Intake Control
Va l v e
Resonator Air
AirOpen
Throttle
Opening
Angle
CloseOpen
Low High
Engine Speed
Air Intake Control Valve Condition EG-128
11. Air Intake Control System
General
The system has a dual path design for air intake. An air intake control valve and actuator control the air flow
path.
As a result, a reduction in intake noise in the low-speed range and an increase in the power output in the
high-speed range are realized.
Layout of Components
Operation
When the engine is operating in the low-to-mid speed range, this control operates the air intake control
valve to close one side of the air cleaner inlet. As a result, the intake area has been minimized and the
intake noise is reduced.
When the engine is operating in the high-speed range, this control operates the air intake control valve
to open both sides of the air cleaner inlet. As a result, the intake area has been maximized and the intake
efficiency is improved.
Page 125 of 2000

ENGINE - 2GR-FE ENGINE
01MEG21Y
01MEG22Y
Engine Coolant Temperature
Sensor
Crankshaft Position Sensor
Combination Meter
Vehicle Speed SignalECM
CAN
Air Conditioning ECUCooling
Fan
ECUFan Motor
No. 1
Fan Motor
No. 2
Except Towing Package Models
Towing Package Models Engine Coolant Temperature
Sensor
Crankshaft Position Sensor
Combination Meter
Vehicle Speed SignalECM
CAN
Air Conditioning ECUCooling
Fan
ECU
No. 1
Cooling
Fan
ECU
No. 2Fan Motor
No. 1
Fan Motor
No. 2EG-129
12. Cooling Fan Control System
General
A cooling fan control system is used. To achieve an optimal fan speed in accordance with the engine coolant
temperature, vehicle speed, engine speed, and air conditioning operating conditions, the ECM calculates
the proper fan speed and sends the signals to the front controller. By receiving the signals from the ECM,
the front controller sends proper fan speed control signals to the cooling fan ECU.
Upon receiving the signals from the front controller, the cooling fan ECU actuates the fan motors.
Wiring Diagram
Page 129 of 2000

ENGINE - 2GR-FE ENGINEEG-133
15. Fail-safe
When the ECM detects a malfunction, the ECM stops or controls the engine according to the date already
stored in the memory.
Fail-safe Chart
DTC No.Fail-safe OperationFail-safe Deactivation Conditions
P0031, P0032,
P0051, P0052ECM turns off air-fuel ratio sensor heater.Ignition switch OFF.
P0037, P0038,
P0057, P0058ECM turns off heated oxygen sensor heater.Ignition switch OFF.
P0100, P0102,
P0103Ignition timing is calculated from engine speed
and throttle angle.“Pass” condition detected.
P0110, P0112,
P0113Intake air temperature is fixed at 20C (68F).“Pass” condition detected.
P0115, P0117,
P0118Engine coolant temperature is fixed at 80C
(176
F).“Pass” condition detected.
P0120, P0121,
P0122, P0123,
P0220, P0222,
P0223, P0604,
P0606, P0607,
P0657, P2102,
P2103, P2111,
P2112, P2118,
P2119, P2135
If ETCS-i (Electronic Throttle Control
System-intelligent) has a malfunction, ECM
cuts off current to throttle control motor.
Throttle control valve returns to predetermined
opening angle (approximately 6.5
) by force of
return spring. ECM then adjusts engine output
by controlling fuel injection (intermittent
fuel-cut) and ignition timing in accordance with
accelerator pedal opening angel to enable
vehicle to continue driving at minimal speed. If
accelerator pedal is depressed firmly and
slowly, vehicle can be driven slowly. If
accelerator pedal is depressed quickly, vehicle
may speed up and slow down erratically.If “Pass” condition is detected and
then the ignition switch is turned
OFF, fail-safe operation will stop
and system will return to normal
operating conditions.
P0327, P0328,
P0332, P0333Max. timing retardation.Ignition switch OFF.
P0351, P0352,
P0353, P0354,
P0355, P0356
Fuel is cut.“Pass” condition detected.
P2120, P2121,
P2122, P2123,
P2125, P2127,
P2128, P2138
Accelerator pedal position sensor has two (main
and sub) sensor circuits. If a malfunction occurs
in either of sensor circuits, ECM detects
abnormal signal voltage difference between two
sensor circuits and switches into limp mode. In
limp mode, remaining circuit is used to calculate
accelerator pedal opening to allow vehicle to
continue driving. If both circuits malfunction,
ECM regards opening angle of accelerator pedal
to be fully closed. In this case, throttle valve will
remain closed as if engine is idling.
If “Pass” condition is detected and
then the ignition switch is turned
OFF, fail-safe operation will stop
and system will return to normal
operating conditions.
Page 134 of 2000
CHASSIS - 4WD SYSTEM
01MCH09Y
Electric Control Coupling
4WD ECU
Four-wheel Drive
Lock Switch
4WD LOCK
Indicator Light
4WD Warning
LightECM
Skid Control ECU
Main Body ECU
Ya w R a t e &
Deceleration Sensor
Steering Angle
SensorThrottle Position Sensor
Crankshaft Position Sensor
Park / Neutral Position
Switch
Speed Sensors
Stop Light Switch
Ambient Temperature
Sensor
Parking Brake Switch
CANH,
CANLCH-67
2. System Diagram