ENGINE - 2AZ-FXE ENGINE
EG-29
ENGINE CONTROL SYSTEM
1. General
The 2AZ-FXE engine is controlled by the THS ECU. The THS ECU determines the motive force required
by the driver in accordance with the pedal effort applied by the driver on the accelerator. Then, the THS
ECU determines the driving conditions of the vehicle in accordance with the vehicle speed, vehicle load,
and various sensor signals. Furthermore, the THS ECU starts and stops the engine in accordance with the
motive force required by the driver, regardless of the driving conditions, and generates the required engine
motive force.
The engine control system of the 2AZ-FXE engine has following system.
System
Outline
An L-type SFI system directly detects the intake air mass with a
hot wire type mass air flow meter.
The fuel injection system is a sequential multiport fuel injection
system.
Fuel injection takes two forms:
SFI
Sequential Multiport
Fuel Injection
Fuel injection takes two forms:
Synchronous injection, which always takes place with the same
timing in accordance with the basic injection duration and an
additional correction based on the signals provided by the sensors.
Non-synchronous injection, which takes place at the time an
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injection request based on the signals provided by the sensors is
detected, regardless of the crankshaft position.
Synchronous injection is further divided into group injection
during a cold start, and independent injection after the engine is
started.
ESA
Ignition timing is determined by the THS ECU based on signals
from various sensors. The THS ECU corrects ignition timing in
ESA
Electronic
Spark Advance
from various sensors. The THS ECU corrects ignition timing in
response to engine knocking.
This system selects the optimal ignition timing in accordance with
Spark Advance
Th s system selects the opt mal gn t on t m ng n accordance w th
the signals received from the sensors and sends the (IGT) ignition
signal to the igniter.
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Electronic Throttle Control
Optimally controls the throttle valve opening in accordance with the
amount of accelerator pedal effort and the condition of the engine
Electronic Throttle Control
System-intelligent
amount of accelerator pedal effort and the condition of the engine
and the vehicle
System intelligent
[See page EG-43]
and the vehicle.
VVT-i
VVT-i
Variable Valve
Controls the intake camshaft to an optimal valve timing in
Variable Valve
Timing-intelligent
Controls the intake camshaft to an optimal valve timing in
accordance with the engine condition.
Timing intelligent
[See page EG-45]
accordance with the engine condition.
Fuel Pump Control
Fuel pump operation is controlled by signals from the THS ECU.
The fuel pump is stopped when the SRS airbag is deployed in a
Fuel Pump Control
[See page EG-49]
The fuel pump is stopped, when the SRS airbag is deployed in a
frontal, side, and rear of side collision.
Cooling Fan Control
Cooling fan operation is controlled by signals from the THS ECU
based on the engine coolant temperature inverter water temperature
Cooling Fan Control
[See page EG-50]
based on the engine coolant temperature, inverter water temperature
and the air conditioning operating condition.
Air Fuel Ratio
Maintains the temperature of the air fuel ratio sensor or oxygen
Air Fuel Ratio
Sensor and Oxygen
Maintains the temperature of the air fuel ratio sensor or oxygen
sensor at an appropriate level to increase accuracy of detection of the
Sensor and Oxygen
Sensor Heater Control
sensor at an appropriate level to increase accuracy of detection of the
oxygen concentration in the exhaust gas.
(Continued)
