Page 40 of 2000

ENGINE - 2AZ-FE ENGINE
00REG17Y
Accelerator Pedal
Position SensorThrottle Valve
Throttle Position SensorThrottle
Control
Motor
Mass Air
Flow MeterECMSkid
Control
ECU
Ignition
CoilFuel
Injector
: CANEG-43
6. ETCS-i (Electronic Throttle Control System-intelligent)
General
The ETCS-i is used, providing excellent throttle control in all the operating ranges. In the 2AZ-FE
engine, the accelerator cable has been discontinued, and an accelerator pedal position sensor has been
provided on the accelerator pedal.
In the conventional throttle body, the throttle valve opening is determined by the amount of the
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.
The ETCS-i controls the IAC (Idle Air Control) system, the TRAC (Traction Control), VSC (Vehicle
Stability Control) system and curise control system.
In case of an abnormal condition, this system switches to the limp mode.
System Diagram
Page 41 of 2000
ENGINE - 2AZ-FE ENGINE
Throttle Body
Throttle Position
Sensor Portion
Reduction
Gears
Throttle ValveMagnetic Yoke
Hall IC
Throttle Control
Motor A
View from A
Cross Section
01NEG44Y
EG-44
Construction
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 ratio 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.
Operation
1) General
The ECM drives the throttle control motor by determining the target throttle valve opening in accordance
with the respective operating condition.
Non-linear Control
Idle Air Control
TRAC Throttle Control
VSC Coordination Control
Cruise Control
Page 42 of 2000

ENGINE - 2AZ-FE ENGINE
005EG13Y
: With Control
: Without Control
Vehicle’s
Longitudinal G
Throttle Valve
Opening Angle
Accelerator Pedal
Depressed Angle
0
0
0
Time
EG-45
2) Normal Throttle Control (Non-linear Control)
It controls the throttle to an optimal throttle valve opening 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 facilitating the vehicle in providing
excellent 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 opening
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.
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 442 of 2000
CC–4CRUISE CONTROL – CRUISE CONTROL SYSTEM
CC
SYSTEM DIAGRAM
Communication table
Sender Receiver Signal Line
ECM Skid control ECU with actuator• VSC operation signal
• Coast brake operation signalCAN
ECM Combination meterCRUISE main indicator light
signalCAN
E129446E01
Page 444 of 2000

CC–6CRUISE CONTROL – CRUISE CONTROL SYSTEM
CC
3. OPERATION OF CRUISE CONTROL
The cruise control switch operates 7 functions: SET,
COAST, TAP-DOWN, RESUME, ACCELERATION
(ACCEL), TAP-UP, and CANCEL. The SET, TAP-DOWN
and COAST functions, and the RESUME, TAP-UP and
ACCEL functions are operated with the same switch.
The cruise control switch is an automatic return type
switch which turns on only when pressed in each arrow
direction and turns off when released.
(a) SET CONTROL
Vehicle speed is stored and constant speed control
is maintained when pushing the switch to -/SET
while driving with the cruise control switch ON (the
CRUISE main indicator light is illuminated), and the
vehicle speed is within the set speed range
(between the low and high speed limits).
(b) COAST CONTROL
The ECM changes the cruise control demanding
throttle opening angle to 0
and decelerates the
vehicle when -/SET on the cruise control switch is
pressed and held while the cruise control system is
operating. When the cruise control switch is
released from -/SET, the vehicle speed is stored and
constant speed control is maintained.
HINT:
• The throttle valve is not fully closed due to idle
speed control, etc.
•w/ VSC:
The brake is also used to decelerate the vehicle.
(c) TAP-DOWN CONTROL
When tapping down the cruise control switch to -/
SET (for approximately 0.5 seconds) while the
cruise control system is in operation, the stored
vehicle speed decreases each time by
approximately 1.6 km/h (1.0 mph). When the cruise
control switch is released from -/SET and the
difference between the driving and stored vehicle
speed is less than 5 km/h (3 mph), the vehicle
speed is stored and constant speed control is
maintained.
(d) ACCEL CONTROL
The throttle valve motor of the throttle position
sensor and motor is instructed by the ECM to open
the throttle valve when +/RES on the cruise control
switch is pressed and held while the cruise control
system is operating. When the cruise control switch
is released from +/RES, the vehicle speed is stored
and constant speed is maintained.
Page 1513 of 2000
BC–10BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
(1) Operation description:
The skid control ECU detects the vehicle's slip
condition by receiving signals from each speed
sensor and the ECM via CAN communication.
The skid control ECU controls engine torque
with the ECM via CAN communication and
brake fluid pressure through the pump and
solenoid valve. The slip indicator light blinks
when the system is operating.
for 4WD: The VSC warning light comes on when
the TRC system malfunctions.
for 2WD: The VSC warning light and SLIP
indicator light comes on when the TRC system
malfunctions.