Download A Engine

Engine
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Engine Overall
Intake & Exhaust System
Fuel System
Charging System
Engine Control System
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Engine
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Engine Overall
• Engine Specification
Model
2UZ-FE (‘03 GX470)
2UZ-FE (‘03 LX470)
No. of Cylinders and
Arrangement
8-Cylinder, V type
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Valve Mechanism
32-Valve DOHC Belt & Gear
Drive
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Displacement
4664 cm3 (284.5 cu in.)
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Bore X Stroke
94.0 X 84.0 mm
(3.70 X 3.31 in.)
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Compression Ration
9.6 : 1
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Maximum Output (SAE-NET)
[kW @ rpm (HP @ rpm)]
175@4800 (235@4800)
Maximum Torque (SAE-NET)
[N·m @ rpm (ft·lbf @ rpm)]
434@3400 (320@3400)
Engine
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Engine Overall
• Engine Specification
The major difference from the 2UZ-FE of ‘03 LX470
•The carbon filter is used at air cleaner
•The number of TWC
•Plastic made type fuel tank is used
•Quick type fuel cap is used
•A no-contact type accelerator pedal position sensor is used
•The construction of evaporative emission control system
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Engine
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Intake & Exhaust System
• Carbon Filter
– Carbon filter adsorb HC in intake system to
reduce evaporative emission
Carbon Filter
(Maintenance-free)
Air Cleaner
Air Flow
Engine
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Intake & Exhaust System
• TWC
– Three TWCs are used to meet LEV I
TWCs
Engine
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Fuel System
• Fuel Tank
– Multiplex layer plastic made type fuel tank is
used to comply the LEV II regulations
Front
Cross Section
Outside
Multiplex
layer
Inside
Engine
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Fuel System
• Fuel Tank Cap
– Quick-type fuel tank cap has been adopted to
improve usability
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Engine
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Charging System
• Alternator
– Compact and lightweight SC (Segment Conductor)
type alternator is used
Segment Conductor
Twisted
Joined
Stator
A Cross Section
Diagram
A
Joined Segment Conductor System
Engine
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Engine Control System
• ETCS-i
• Evaporative Emission Control System
• Cranking Hold Function
• Diagnosis
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Engine
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Engine Control System
• ETCS-i
– In the new 2UZ-FE engine, the link-less type
ETCS-i is used
’03 GX470
ECM
Accelerator Pedal
Position Sensor
Throttle
Position Sensor
Throttle
Control Motor
Engine
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Engine Control System
• ETCS-i
– A no-contact type throttle position sensor is used
Reduction
Gears
Throttle
Position Sensor
Hall ICs
Magnets
Throttle Control
Motor
Throttle
Valve
Engine
Engine Control System
• ETCS-i
– Throttle position sensor converts into electric
signals the magnetic flux density
VC
VTA1
VC
E2
VTA2
Hall
IC
VTA
Hall ICs
VTA2
E2
Magnets
Output Voltage (V)
ECM
Magnet
ECM
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VTA2
5
VTA1
VTA
0
Full Close
Full Open
Throttle Valve Opening Angle
Engine
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Engine Control System
• ETCS-i
– A no-contact type accelerator pedal position
sensor is used
Magnets
Hall ICs
Accelerator
Pedal Arm
Engine
Engine Control System
• ETCS-i
– Accelerator pedal position sensor converts into
electric signals the magnetic flux density
Magnets
VPA
EPA
VCPA
VPA2
Hall
ICs
EPA2
VCP2
ECM
Output Voltage (V)
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5
VPA2
VPA
0
Full Close
Full Open
Accelerator Pedal Depressed Angle
Engine
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Engine Control System
• Evaporative Emission Control System
– The construction is changed to comply with the
LEV-II evaporative emission regulations
To Intake
Manifold
Tank Pressure
Valve
Vapor Pressure
Sensor
Restrictor
Passage
Purge
Valve
Air Filter
Charcoal
Canister
Canister
Close Valve
The construction is simpler than the
conventional vacuum type
Engine
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Engine Control System
• Evaporative Emission Control System
– Location
Purge
Valve
Service
Port
Tank Pressure
Valve
Charcoal
Canister
Air
Filter
Vapor Pressure
Sensor
Canister
Close Valve
Engine
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Engine Control System
• Evaporative Emission Control System
– Charcoal canister assembly
Canister
Closed
Valve
Charcoal
Canister
(3.0 liters)
Tank
Pressure
Valve
To Intake
Manifold
From Fuel Tank
To Fresh
Air Line
Engine
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Engine Control System
• Evaporative Emission Control System
– The vapor guide prevents the vapor gas without
passing through the activated charcoal
From Fuel Tank
From Fuel Tank
Vapor Guide
To Intake Manifold
Clean air
Absorb
vapor gas
With vapor guide
To Intake Manifold
Include
vapor gas*
Without vapor guide
*: It will affect the air-fuel ratio control of the engine
Engine
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Engine Control System
• Evaporative Emission Control System
– Tank pressure valve controls the flow rate of the
vapor gas from fuel tank to charcoal canister
Tank Pressure Valve
Vapor Gas
(From Fuel
Tank)
Restrictor Passage
When refueling
(Tank pressure is large)
From
Fuel Tank
Engine
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Engine Control System
• Evaporative Emission Control System
– The restrictor passage prevents the large
amount of vacuum that is created during system
monitoring from entering the fuel tank
From Fuel
Tank
Restrictor
Passage
Vacuum
Restrictor
Passage
If the large amount of vacuum enters the fuel tank during system
monitoring, system monitoring is not performed normally
Engine
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Engine Control System
• Evaporative Emission Control System
– The air filter prevents dust and debris in the
fresh air from entering the system
To Charcoal
Canister
To Fresh Air
The air filter is maintenance-free
Engine
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Engine Control System
• Evaporative Emission Control System
– Stored fuel vapors are purged from the charcoal
canister when the purge valve is opened by ECM
ECM
Duty
To Intake
Manifold
Stored fuel
vapors
Atmosphere
OPEN
OPEN
Engine
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Engine Control System
• Evaporative Emission Control System
– When refueling, the fuel vapors enter to the
charcoal canister and they are cleaned
The internal
pressure increases
ECM
OPEN
Close
OPEN
The fuel vapors
are Cleaned
Engine
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Engine Control System
• Evaporative Emission Control System
– When the initial conditions are met, the ECM
introduces a vacuum into the system and
monitors system to detect system malfunction
Initial conditions are met
0 mmHg
P1’
P1
Fuel Tank
Pressure
Value B
Value A
Purge
Valve
Open
Close
Open
Canister
Close
Closed Valve
P2
The ECM monitors
the amount of
pressure increase
in the fuel tank
Engine
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Engine Control System
• Evaporative Emission Control System
– System monitoring (Step1)
The ECM measures the amount of pressure increase (P1) in the fuel tank
P1
Fuel Tank
Pressure
0 mmHg
P1
Purge
Valve
Canister
Closed Valve
15 secs.
Close
Close
Engine
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Engine Control System
• Evaporative Emission Control System
– System monitoring (Step2)
The ECM opens the purge valve and introduces a vacuum into the fuel tank
Fuel Tank
Pressure
Purge
Valve
Canister
Closed Valve
Open
Close
Engine
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Engine Control System
• Evaporative Emission Control System
– System monitoring (Step3)
The ECM measures the amount of pressure increase (P2)in the fuel tank
Value B
Fuel Tank
Pressure
Value B
Value A
Purge
Valve
Canister
Closed Valve
P2
Below
value A
P2
Close
Close
5 secs.
Engine
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Engine Control System
• Evaporative Emission Control System
– System leak judgment
P2 Measurement
P2 > Reference Value*
P2 < Reference Value*
Presumes presence of system leak
Judges absence of system leak
*: Reference value is
stored in the ECM
Normal system control
P1 is small
P1 is large
Judges presence of system leak
Judges P1 again (P1’)
P1’ Measurement
P1’ is small
P1’ is large
Judges presence of system leak
Repeats judgment
The MIL illuminates and ECM stores
the following DTCs in its memory
Level of Leak
DTC
Very small, small
or medium leak
P0442 and/or P0456
Large leak
P0441, P0442 and P0446
Engine
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Engine Control System
• Evaporative Emission Control System
– VSV monitoring
(Normal condition)
Purging
Purge
Valve
Canister
Closed
Valve
Fuel Tank
Pressure
Open
Open
System monitoring
Close
Close
System leak judgment
Engine
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Engine Control System
• Evaporative Emission Control System
– VSV monitoring
(Purge valve open malfunction)
Purge
Valve
Engine
Starting
When the ECM is measuring the P1 value, the
pressure in the fuel tank drops rapidly
Open
Normal
Condition
Canister
Closed
Valve
Fuel Tank
Pressure
It remains in a constant,
slight vacuum state
Malfunction
Judgment
DTC P0441 is memorized, The MIL illuminates
Engine
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Engine Control System
• Evaporative Emission Control System
– VSV monitoring
(Purge valve close malfunction)
Purge
Valve
No vacuum is introduced
Close
Canister
Closed
Valve
Fuel Tank
Pressure
Malfunction Judgment
The pressure does not change
DTC P0441, P0442 and P0446 is
memorized, The MIL illuminates
Engine
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Engine Control System
• Evaporative Emission Control System
– VSV monitoring
(Canister closed valve open malfunction)
It is not possible to completely
introduce a vacuum
Purge
Valve
Canister
Closed
Valve
Open
Fuel Tank
Pressure
Malfunction Judgment
A slight vacuum is created
DTC P0441, P0442 and P0446 is
memorized, The MIL illuminates
Engine
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Engine Control System
• Evaporative Emission Control System
– VSV monitoring
(Canister closed valve close malfunction)
Purge
Valve
Canister
Closed
Valve
A large amount of vacuum is introduced
Close
Fuel Tank
Pressure
Malfunction
Judgment
DTC P0446 is memorized, The MIL illuminates
Engine
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Engine Control System
• Cranking Hold Function
– Once the ignition switch is turned to the START
position, this control continues to operate starter
until engine starts
“Start”
“ON”
Ignition
Switch
Operates
Automatically
Starter
Operate
Stop
Engine starts
Engine
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Engine Control System
• Cranking Hold Function
– System Diagram
Audio &
Illumination
Starter
Relay马达
继电器
Starter
马达
Park/Neutral
Position Switch
Engine ECU
(ECM)
ACC
ACC Cut
Relay
ST
THW
NE
Ignition
Switch
Engine Coolant
Temp. Sensor水稳传感器
Crankshaft Position
Sensor机油位置传感器
Engine
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Engine Control System
• Cranking Hold Function
– The ACC cut relay cuts off the ACC circuit while
engine is cranking to prevent the accessory
illumination from operating intermittently
Audio &
Illumination
Starter
Relay
Park/Neutral
Position Switch
Engine ECU
(ECM)
ACC
ACC Cut
Relay
ST
Ignition
Switch
THW
Engine Coolant
Temp. Sensor
NE
Crankshaft
Position Sensor
Starter
Engine
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Engine Control System
• Cranking Hold Function (Operation)
Ignition
Switch
Start
0.2 sec.
or more
: With this system
: Without this system
ON
ACC Cut
Relay
Automatically
Controlled
Starter
Relay
Judgment
NE
Signal
Time
Engine
Engine Control System
• Cranking Hold Function
– The maximum cranking time will be changed with
engine coolant temp.
Reference Value!!
Engine
Coolant Temp.
(°C (°F))
Max. Cranking
Time
(sec.)
100 (212)
Approx. 2
0 (32)
Approx. 5
-30 (-22)
Approx. 25
Max. Cranking Time
(sec.)
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Confidential -A
5
0
Engine Coolant Temp.
(C)
When engine coolant temp. is
lower, the time limit is longer
Engine
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Engine Control System
• Cranking Hold Function
– If the engine is already running, the ECM will not
energize to the starter relay
Ignition
Switch
Start
ON
Starter
Relay
NE
Signal
OFF
700 rpm
Engine is
already running
Engine
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Engine Control System
• Cranking Hold Function
– If the engine speed becomes 1200 rpm or more
while cranking, the ECM turns off a starter relay
to prevent starter overrun
Ignition
Switch
Start
Driver operates
intentionally
ON
Starter
Relay
NE
Signal
OFF
1200 rpm
Time
Engine
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Engine Control System
• Cranking Hold Function
– When a starter is intentionally operated by the
driver, the ECM turns off a starter relay after
30 sec. in order to prevent starter overheating
Ignition
Switch
Start
Driver operates
intentionally
ON
Starter
Relay
30 sec.
OFF
NE
Signal
Engine does not start (Problem)
Time
Engine
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Engine Control System
• Diagnosis
– To comply with the OBD-II regulations, all the
DTC have been made to correspond to SAE
controlled codes. Some of the DTC have been
further divided into smaller detection area than
in the past, and new DTC have been assigned
to them.
Example
New DTC
Old DTC
DTC
P0135
DTC
Detection Item
Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 1)
Detection Item
P0031
Oxygen Sensor Heater Control
Circuit Low (Bank 1 Sensor 1)
P0032
Oxygen Sensor Heater Control
Circuit High (Bank 1 Sensor 1)