2013 SSANGYONG TURISMO engine

15-20
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. -
-
- The system measures the pulse at initial injection to reduce the engine vibration.
B. Purpose of MDP learning

15-210000-00
C. Learning Conditions
Idle MDP learning Drive MDP learning
Coolant temperatureover 60℃ over 60℃
Vehicle speedIdling over 50km/h (over 5 seconds)
Engine rpm2,000 to 2,500 rpm
Fuel temperature0 < Fuel temperature < 80℃
Learning2 times for each cylinder (every 5
seconds)2 times for each cylinder
(every 5 seconds)
If MDP learning is not properly performed, engine vibration and injection could be occurred.
MDP learning should be performed after replacing ECU, reprogramming and replacing injector. -
-
D. Injector characteristic curve for rail pressure
The fuel injection curve is also called injection characteristic curve as shown above. The amount of
injected fuel is proportional to the square root of injection period and rail pressure.

15-230000-00
This is done periodically under certain operating conditions. When the resetting is finished, the new
minimum pulse value replaces the value obtained during the previous resetting. The first MDP value is
provided by the C3I. Each resetting then allows the closed loop of the MDP to be updated according to
the deviation of the injector.
B. Detection of leaks in the cylinders
The accelerometer is also used to detect any injector which may have stuck open. The detection
principle is based on monitoring the ratio. If there is a leak in the cylinder, the accumulated fuel self-
ignites as soon as the temperature and pressure conditions are favorable (high engine speed, high
load and small leak).
This combustion is set off at about 20 degrees before TDC and before main injection.
The ratio therefore increases considerably in the detection window. It is this increase which allows the
leaks to be detected. The threshold beyond which a fault is signaled is a percentage of the maximum
possible value of the ratio.
Because of the severity of the recovery process (engine shut-down), the etection must be extremely
robust.
An increase in the ratio can be the consequence of various causes:
Pilot injection too much
Main combustion offset
Fuel leak in the cylinder -
-
-
If the ratio becomes too high, the strategy initially restricts the pilot injection flow and retards the main
injection. If the ratio remains high despite these interventions, this shows that a real leak is present, a
fault is signaled and the engine is shut down.
C. Detection of an accelerometer fault
This strategy permits the detection of a fault in the sensor or in the wiring loom connecting the sensor
to the ECU.
It is based on detection of the combustion. When the engine is idling, the detection window is set too
low for the combustion caused by the main injection. If the ratio increases, this shows that the knock
sensor is working properly, but otherwise a fault is signaled to indicate a sensor failure. The recovery
modes associated with this fault consist of inhibition of the pilot injection and discharge through the
injectors.

15-24
(8) Swirl control
A. Overview
Variable swirl valve ▶
The strong swirl caused by intake air is important element for anti-locking function in diesel engine. The
swirl control valve partially closes the intake port to generate the swirl according to the engine
conditions. When the engine load is in low or medium range, the swirl could not be generated because
the air flow is slow. To generate strong swirl, there are two passages in intake manifold, and one of
them has the valve to open and close the passage. When the valve closes the passage, the air flow
through the another passage will be faster, and the strong swirl will be generated by the internal
structure of the passage. This swirl makes the better mixture of air and fuel, eventually the combustion
efficiency in combustion chamber could be improved. This provides the enhanced fuel consumption,
power and EGR ratio.
Components ▶
HFMCrankshaft position sensorVariable swirl valve
Coolant temperature
sensorAccekerator pedal
moduleD20DTR ECU

15-26
C. Types of swirl
Swirl: One cylinder has two intake air ports, one is set horizontally and
the other one is set vertically. Swirl is the horizontal air flows in
cylinder due to the horizontal intake air ports.
Tumble: Tumble is the vertical air flows in cylinder due to the vertical
intake air port
Squish is the air flow at end of compression process according to the
design of piston head. In this DI engine, the squish is generated to
bowl type.
D. Swirl control
In DI type diesel engine, the liquefied fuel is injected into the cylinder directly. If the fuel is evenly
distributed in short period, the combustion efficiency could be improved. To get this, there should be
good air flow in cylinder. In general, there are two intake ports, swirl port and tangential port, in each
cylinder. The swirl port generates the horizontal flow and the tangential port generates the longitudinal
flow. In low/mid load range, the tabgential port is closed to increase the horizontal flow. Fast flow
decreases the PM during combustion and increases the EGR ratio by better combustion efficiency.

15-270000-00
Load Engine speedSwirl
valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000 rpm Closed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas))
High speed,
High loadover 3,000 rpm Open LightIncrease charge efficiency, higher
engine power
The variable swirl valve actuator operates when
turning the ignition switch ON/OFF position to
open/close the swirl valve. In this period, the
soot will be removed and the learning for swirl
valve position is performed.
Swirl: This is the twisted (radial) air flow along the cylinder wall during the intake stroke. This
stabilizes the combustion even in lean air-fuel mixture condition.
Swirl valve
E. Features
Swirl and air intake efficiency
To generate the swirl, the intake port should be serpentine design. This makes the resistance in air
flow. The resistance in air flow in engine high speed decreases the intake efficiency. Eventually, the
engine power is also decreased, Thus, the swirl operation is deactivated in high speed range to
increase the intake efficiency.
Relationship between swirl and EGR
To reduce Nox, it is essential to increase EGR ratio. However, if EGR ratio is too high, the PM also
could be very higher. And, the exhaust gas should be evenly mixed with newly aspired air.
Otherwise, PM and CO are dramatically increased in highly concentrated exhaust gas range and
EGR ratio could not be increased beyond a certain limit. If the swirl valve operates in this moment,
the limit of EGR ratio will be higher. -
-
F. Relationship between swirl and fuel injection pressur
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If the
swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when
the swirl is too strong.

15-28
Electric throttle
bodyAccelerator
pedal
moduleD20DTR
ECU
(9) EGR control
A. Overview
The EGR (Electric-Exhaust Gas Recirculation) valve reduces the NOx emission level by recirculating
some of the exhaust gas to the intake system.
To meet Euro-V regulation, the capacity and response rate of E-EGR valve in D20DTR engine have
been greatly improved. The EGR cooler with high capacity reduces the Nox, and the bypass valve
reduces the CO and HC due to EGR gas before warming up.
Also, the engine ECU adjusts the E-EGR opening by using the air mass signal through HFM sensor. If
the exhaust gas gets into the intake manifold when the EGR valve is open, the amount of fresh air
through HFM sensor should be decresed.
B. Components
E-EGR cooler
Coolant
temperature
sensorOxygen sensor
HFM (intake
air
temperature)
Crankshaft
position
sensorE-EGR valve
T-MAP
sensor

15-30
D. Bypass control for EGR cooler
Cooler temperature ▶
When the coolant temperature is below 70℃, the exhaust gas is bypassed the EGR cooler.
Exhaust gas temperature ▶
When the exhaust gas tem
perature is below 300℃, the exhaust gas is bypassed the EGR cooler
Otherwise, PM could be increased due to too low exhaust gas temperature.
E. Control elements for EGR system
Accelerator pedal (engine load) - Indicates the driver's intention and engine load. If the load goes
up, the EGR ratio is decreased.
T-MAP (boost pressure map stored in ECU) - Compensates the difference in boost pressure by
adjusting EGR ratio.
Engine rpm - Used as the signal for determining EGR operating range.
Coolant temperature - When the coolant temperature is low, NOx is decreased but PM could be
increased. So, to reduce PM, decrease EGR ratio when the coolant temperature is low.
Intake air mass and temperature - HFM sensor measures the intake air mass to calculate the
actual EGR volume. If the air mass is larger than programmed value in map, EGR ratio will be
higher.
EGR position sensor - Detects the actual opening angle of EGR valve and performs feedback
function according to PWM control by ECU.
Wide band oxygen sensor - Detects the oxygen volume in exhaust gas to check if the EGR ratio is
proper.
Electronic throttle body - Keeps EGR ratio to optimized level by controlling the throttle body in EGR
operating range (decreasing pressure in intake manifold). -
-
-
-
-
-
-
-