15-16
Pilot injection timing control ▶
The pilot injection timing is determined as a function of the engine speed and of the total flow.
The elements are:
A first correction is made according to the air and coolant temperatures. This correction allows the
pilot injection timing to be adapted to the operating temperature of the engine.
A second correction is made according to the atmospheric pressure. This correction is used to adapt
the pilot injection timing as a function of the atmospheric pressure and therefore the altitude. -
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(4) Injection Timing Control
Injection timing is determined by the conditions below. ▶
Coolant temperature
Hot engine - Retarded to reduce Nox
Cold engine - Advanced to optimize the combustion 1.
Atmospheric pressure
Advanced according to the altitude 2.
Warming up
Advanced during warming up in cold engine 3.
Rail pressure
Retarded to prevent knocking when the rail pressure is high 4.
EEGR ratio
Advanced to decrease the cylinder temperature when EGR ratio increases 5.
Main injection timing control ▶
The pulse necessary for the main injection is determined as a function of the engine speed and of the
injected flow.
The elements are:
A first correction is made according to the air and coolant temperatures.
This correction makes it possible to adapt the timing to the operating temperature of the engine.
When the engine is warm, the timing can be retarded to reduce the combustion temperature and
polluting emissions (NOx). When the engine is cold, the timing advance must be sufficient to allow
the combustion to begin correctly.
A second correction is made according to the atmospheric pressure.
This correction is used to adapt the timing advance as a function of the atmospheric pressure and
therefore the altitude.
A third correction is made according to the coolant temperature and the time which has passed since
starting.
This correction allows the injection timing advance to be increased while the engine is warming up
(initial 30 seconds). The purpose of this correction is to reduce the misfiring and instabilities which are
liable to occur after a cold start. -
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15-170000-00
A fourth correction is made according to the pressure error.
This correction is used to reduce the injection timing advance when the pressure in the rail is higher
than the pressure demand.
A fifth correction is made according to the rate of EGR.
This correction is used to correct the injection timing advance as a function of the rate of exhaust gas
recirculation. -
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When the EGR rate increases, the injection timing advance must in fact be increased in order to
compensate for the fall in termperature in the cylinder.
A. Main Flow Control
The main flow represents the amount of fuel injected into the cylinder during the main injection. The pilot
flow represents the amount of fuel injected during the pilot injection.
The total fuel injected during 1 cycle (main flow + pilot flow) is determined in the following manner.
When the driver depress the pedal, it is his demand which is taken into account by the system in order
to determine the fuel injected.
When the driver release the pedal, the idle speed controller takes over to determine the minimum fuel
which must be injected into the cylinder to prevent the enigne from stalling. -
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It is therefore the greater of these 2 values which is retained by the system. This value is then compared
with the lower flow limit determined by the ESP system.
As soon as the injected fuel becomes lower than the flow limit determined by the ESP system, the
antagonistic torque (engine brake) transmitted to the drive wheels exceeds the adherence capacity of
the vehicle and there is therefore a risk of the drive wheels locking.
The system thus chooses the greater of these 2 values (main flow & pilot flow) in order to prevent any
loss of control of the vehicle during a sharp deceleration.
As soon as the injected fuel becomes higher than the fuel limit determined by the ASR trajectory control
system, the engine torque transmitted to the wheels exceeds the adhesion capacity of the vehicle and
there is a risk of the drive wheels skidding. The system therefore chooses the smaller of the two values
in order to avoid any loss of control of the vehicle during accelerations.
The anti-oscillation strategy makes it possible to compensate for fluctuations in engine speed during
transient conditions. This strategy leads to a fuel correction which is added to the total fuel of each
cylinder.
A switch makes it possible to change over from the supercharge fuel to the total fuel according to the
state of the engine.
Until the stating phase has finished, the system uses the supercharged fuel.
Once the engine changes to normal operation, the system uses the total fuel. -
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(5) Fuel Control
The main fuel is obtained by subtracting the pilot injection fuel from the total fuel.
A mapping determines the minimum fuel which can control an injector as a function of the rail pressure.
As soon as the main fuel falls below this value, the fuel demand changes to 0 because in any case the
injector is not capable of injecting the quantity demand.
15-210000-00
MDP (Minimum Drive Pulse ) refers to the
minimum power supply pulse for injection which
the injector can perform. It is possible to control
the fuel volume for each injector accurately
through correct learning for the MDP value. The
basic process of MDP learning is that the pulse
slightly higher than MDP is supplied and then (b)
the vibration generated from the cylinder is
detected. The knock sensor detects the vibration
from the engine after a small volume of fuel is
injected. And the time interval between the points
of injection and vibration is measured so that
MDP can be learned. MDP learning is helpful to
prevent engine vibration, high emission and
power reduction through performing calibration
for the old injectors. During MDP learning, a little
vibration and noise can be occur for a while. This
is because the fuel pressure is increased
instantaneously and the exact injection value is
not input, so that the exact engine vibration
timing can be detected.
(6) MDP Learning Control
A. MDP Learning
When the pulse value that the injector starts injection is measured, it is called minimum drive pulse
(MDP). Through MDP controls, can correct pilot injections effectively. Pilot injection volume is very small,
1 to 2 mm/str, so precise control of the injector can be difficult if it gets old. So there needs MDP learning
to control the very small volume precisely through learning according to getting older injectors.
Control the fuel injection volume precisely by MDP learning even for the old injector.
ECU corrects the pilot injection effectively by MDP control.
MDP learning is performed by the signal from knock sensor. -
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- The system measures the pulse at initial injection to reduce the engine vibration.
B. Purpose of MDP learning
01-8
Front View ▶
NO. FUNCTION NO. FUNCTION
1 HFM Sensor 12 Intake Manifold
2 Intake Air Duct 13 Cylinder Head
3 Cylinder Head Cover 14 Exhaust Manifold
4 Ignition Coi 15 Dipstick Guide Tube and Gauge
5 Spark Plug Connector 16 Connecting Rod
6 Fuel Distributor 17 Crankshaft
7 Injector 18 Engine Mounting Bracket
8 Exhaust Camshaft 19 Starter
9 Intake Camshaft 20 Crankcase
10 Valve Tappet 21 Oil Pump Sprocket
11 Intake Valve 22 Oil Pan
NO. FUNCTION NO. FUNCTION
23 Camshaft Adjuster 29 Oil Pump Drive Chain
24 Oil Filler Cap 30 Oil Strainer
25 Engine Hanger Bracket 31 Oil Pump
26 Cooling Fan and Viscous Clutch 32 Ring Gear and Flywheel of Drive Plate
27 Oil Filter 33 Piston
28 Timing Chain
Side View ▶
06-6
2. DESCRIPTION AND OPERATION
1) General Description
The cooling system maintains the engine temperature at an efficient level during all engine operating
conditions.
When the engine is cold, the cooling system cools the engine slowly or not at all. This slow cooling o
f
the engine allows the engine to warm up quickly.
The cooling system includes a radiator and recovery subsystem, cooling fans, a thermostat and
housing, a water pump, and a water pump drive belt. The timing belt drives the water pump.
All components must function properly for the cooling system to operation. The water pump draws the
coolant from the radiator. The coolant then circulates through water jackets in the engine block, the
intake manifold, and the cylinder head. When the coolant reaches the operating
temperature of the thermostat, the thermostat opens. The coolant then goes back to the radiator where
it cools.
This system directs some coolant through the hoses to the heat core. This provides for heating and
defrosting.
The coolant reservoir is connected to the radiator to recover the coolant displaced by expansion from
the high temperatures. The coolant reservoir maintains the correct coolant level.
The cooling system for this vehicle has no radiator cap or filler neck. The coolant is added to the cooling
system through the coolant reservoir.
2) Radiator
This vehicle has a lightweight tube-and-fin aluminum radiator. Plastic tanks are mounted on the upper
and the lower sides of the radiator core.
On vehicles equipped with automatic transaxles, the transaxle fluid cooler lines run through the radiato
r
tank.
A radiator drain plug is on this radiator.
To drain the cooling system, open the drain plug.
3) Coolant Reservoir
The coolant reservoir is a transparent plastic reservoir, similar to the windshield washer reservoir.
The coolant reservoir is connected to the radiator by a hose and to the engine cooling system by anothe
r
hose.
As the vehicle is driven, the engine coolant heats and expands. The portion of the engine coolant
displaced by this expansion flows from the radiator and the engine into the coolant reservoir. The ai
r
trapped in the radiator and the engine is degassed into the coolant reservoir.
When the engine stops, the engine coolant cools and contracts. The displaced engine coolant is then
drawn back into the radiator and the engine. This keeps the radiator filled with the coolant to the desired
level at all times and increases the cooling efficiency.
Maintain the coolant level between the MIN and MAX marks on the coolant reservoir when the system is
cold.
01-173680-01
5. ELECTRONIC CONTROL SYSTEM
1) Overview
The transmission control unit (TCU) and its input/output networks control the operations of transmission:
Shift timing
Line pressure
Clutch pressure (shift feel)
Torque converter clutch -
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In addition, the TCU receives input signals from certain transmission-related sensors and switches. The
TCU also uses these signals when determining transmission operating strategy. Using all of these input
signals, the TCU can determine when the time and conditions are right for a shift, or when to apply or
release the torque converter clutch. It will also determine the pressure needed to optimise shift feel. To
accomplish this, the TCU operates six variable bleed control solenoids and four ON/OFF solenoids to
control the operations of transmission.
2) Transmission Control Unit (TCU)
The transmission control unit (TCU) is mounted under the driver's seat and controls the operation of the
transmission.
TCU processes the analog information from the internal sensors and the digital information through CAN
communication lines. TCU monitors all the input and output signals. If there is any failure, TCU changes
the system to “Limp Home Mode” and alerts to the driver through the warning lamp on the
instrument cluster.
(1) Hard-wired (Analog) Input/Output
Input/Output Data between TGS Lever and TCU ▶
Position and conditions of gear select lever
Driving moded (Winter or Standard) -
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Position of inhibitor switch - Input/Output Data between Inhibitor and TCU ▶
6 control signals for variable bleed solenoid
4 control signals for ON/OFF solenoid
Transmission input speed
Transmission output speed
Transmission oil temperature
EMM (Embeded Memory Module) -
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- Input/Output Data between Automatic Transmission and TCU ▶
Input/Output Data between Self Diagnostic Connector and TCU ▶
Various DTC codes and TCU information -
01-213680-01
Pressure Modulation ▶
To provide a higher level of shift comfort and durability, the hydraulic pressure in the shift related friction
elements of the transmission must be matched accurately to the input torque to transmission. This
hydraulic pressure is composed of a hydraulically pre-set basic pressure and a control pressure which is
set by one of the variable bleed solenoids.
The transmission input torque can be directly calculated from the following operating parameters:
engine torque signals
engine speed or any signal transmitted from ECU through CAN lines
converter slip -
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Separate pressure characteristics for each gear change make it possible to adapt precisely to the
particular shift operation.
5) Shift Mode Selection by TCU
The driver can select Standard (S) or Winter mode (W) with the mode switch. TCU automatically
changes the shift mode according to the transmission oil temperature, uphill or downhill gradient, and
altitude to keep the good driving conditions.
Standard Mode (S) ▶
Uphii and Downhill Mode ▶
Altitude Mode ▶ Standard Mode is selected when setting the mode switch in Standard (S) position with the gear select
<0093008c009d008c0099004700900095004702c8006b02c9004700880095008b0047009b008f008c0047009b009900880095009a00940090009a009a00900096009500470096009000930047009b008c00940097008c00990088009b009c0099008c004700
9000950047009500960099009400880093004700960097008c>rating range. Proper shift timing
provides the optimized fuel economy and good driving conditions.
In this mode, the operating points of torque converter lock-up clutch and the shifting points are adjusted
according to the vehicle weight.
In this mode, the shifting points are automatically adjusted according to the altitude to compensate the
engine torque changes due to barometric pressure and temperature.
03-73170-01
2) Function of N Switch
(1) Aids a smooth start of the vehicle by raising the RPM during the gear
shifting when the engine is cold.
When the vehicle is trying to start from the stopped state (vehicle speed below 3 km/h), the N switch
determines the shifting timing by using the clutch switch and the N switch. It raises the engine RPM (100
~ 200 rpm). Operation conditions are as follows.
The vehicle speed is at the stopped state (Vehicle speed below 3km/h detection).
While depressing the clutch (Clutch switch detection).
The gear lever is at a position other than neutral (N switch detection).
Start the vehicle while depressing the clutch pedal (Clutch switch detection).
The RPM increases in accordance with the temperature of the engine coolant
(Engine coolant temperature sensor detection). -
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appx. 100 rpm increase
appx. 100 ~ 170 rpm increase
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95009b005000610047008800990096009c0095008b00470059>00 rpm ·
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When the gear has been smoothly shifted and the vehicle speed exceeds 3km/h, it returns to the
previous operation interval of the engine RPM. -
In case of Actyon, the N switch signal is transmitted to the instrument panel, and then the instrument
panel transmits it to the engine ECU through the CAN communication.
Vehicle Made After 04.09.15 Actyon