Page 230 of 796
03-232210-01
T-MAP sensor
Measuring booster pressure
and temperatureFuel rail assembly
Relieving the pulsation.
Measuring the fuel pressure.
Distributing the fuel to injectors.
Plunger type HP pump (1,800 bar)
Vane type LP pump (6 bar)
Accelerator pedal position
sensor
Detecting driver's intention for
speed up/down
Fuel filter assembly
Supplying clean fuel/fuel
heating/water separation by
priming pump
High pressure pump
Generating high pressurized fuel
and supplying it according to engine
rpm, required volume, required
pressure
Page 271 of 796

07-6
2. FUNCTIONS OF LUBRICATION
1) Lubrication
It creates a viscous barrier between moving parts that reduces friction, which means less heat and
longer life for those parts. As a lubricant, oil must maintain a protective film to prevent metal-to-metal
contact. It must be fluid enough to allow easy starting and to circulate quickly through the engine, yet
remain thick enough at higher operating temperatures and speeds to provide adequate lubrication.
2) Cooling
Combustion heat and friction energy must be removed from the engine in order to prevent its
overheating. Most of heat energy is taken by the engine oil.
Clean oil passages, proper viscosity and low contamination provide sufficient flow rate of the engine oil
and effective cooling.
3) Sealing
It helps to seal the space between the pistons and the cylinder walls so that compression is more
effective and power is not lost during combustion.
4) Anti-corrosion
As a corrosion inhibitor, oil coats internal engine parts to prevent surface rust on the inside of the
engine which can be caused by blow-by products and water formed in combustion. It must also be
capable of neutralizing the acids that are formed by combustion blow-by and oil oxidation at high
temperatures.
5) Cleaning
The small particles of dirt or other contaminants are suspended in oil and carried away to be filtered
out. As a detergent, engine oil must be able to gather and suspend dirt and other contaminants until
the oil can leave them as it passes through the filter and returns to the internal engine environment.
Page 276 of 796

08-71520-00
3. CAUTIONS
If 100% of anti-freeze is added, the water pump vane can be damaged and thermal conductivity
can be decreased resulting in poor circulation in the cooling system which leads to overheated
engine.
Use of non-recommended coolant could cause damage to the cooling system and overheating of
the engine.
Opening the coolant reservoir cap while the engine is running or hot can cause burns by hot
steam or water.
To open the coolant reservoir cap, wrap the cap with a wet towel or thick cloth after the engine is
cooled down sufficiently.
If cool water is added to the heated engine, the engine or radiator can be deformed.
The anti-freeze in the coolant can damage the painted surface, so avoid the contact of the coolant
to the painted body.
The anti-freeze and water should be mixed in proper mixture ratio. Never add only water when
adding coolant.
If the anti-freeze content is too low, the coolant can be frozen while the engine can be overheated
if anti-freeze content is too high. -
-
-
-
-
-
-
-
Page 291 of 796
10-4
1. OVERVIEW
The pre-heating system for D20DTR engine has the glow plug to the cylinder head (combustion
chamber), and improves the cold start performance and reduces the emission level.
The pre-heating resistor (air heater) is used to heat the intake air.
This enables the diesel fuel to be ignited in low temperature condition.
The ECU receives the information such as, engine rpm, coolant temperature, engine torque, etc.,
through CAN communication during pre-heating process; and the pre-heating control unit controls the
pre-heating, heating during cranking and post-heating by the PWM control.
Glow plug
Engine ECU (D20DTR)Glow indicator
Glow plug control unit
(GCU)
Page 295 of 796
10-8
(2) Pre-heating time control based on battery voltage
GCU monitors the battery voltage. If it is low, GCU extends the pre-heating time.
GCU monitors the energy to glow plugs (the amount of pre-heating energy is always same). -
-
GCU monitors the battery voltage. If it is low, GCU extends the pre-heating time to get enough
energy. -
GCU monitors the battery voltage. If it is low, GCU increases PWM duty.. -
Page 296 of 796
10-91413-00
(3) Power control
GCU PWM control
This describes the voltage supplying types to glow plugs. -
GCU estimates the temperature of glow plug for pre-heating. To avoid the power loss and overheat,
GCU supplies the lowest power for getting target temperature when turning ON the ignition from
OFF. -
(4) Operation
Frequency: 20~33Hz
PWM control duty ratio
- 1st step: 100%
- 2~3 step: 35%
- 4th step: 23%
Page 324 of 796

14-12
Rear temperature sensor
Measure the outlet
temperature of DOC.
This sensor is located at the
rear side of DOC and
monitors the overheating of
CDPF and post injection
volume.
Differential pressure sensor
Measures the difference between
inlet and outlet pressures of CDPF.
If the difference is higher than the
specified value when collecting the
PM, this makes the post injection
for forced recycling of PM.
Front temperature sensor
Measures the temperature of
exhaust gas.
This sensor is located at the rear
side of exhaust manifold and
monitors the temperature of
combusted gas to prevent the
exhaust system from overheating.
When the temperature gets higher,
this sensor cuts off the fuel delivery
and controls the EGR to lower the
temperature.
Engine ECU (D20DTR)
T-MAP sensorIntake air
mass
Measures
the
excessive
amount of
PM.
Injector (C31)
Controls the post injection.
Electric throttle body
Controls the intake air mass.
HFM sensor
Wide band
oxygen
sensor
Boost
pressure/
temperature
Page 370 of 796
15-42
PTC Fuse and Relay
(13) PTC heater control
A. Overview
The supplementary electrical heater is installed in DI engine equipped vehicle as a basic equipment.
The PTC system is operated according to two temperature values measured at the coolant temperature
sensor and HFM sensor. This device is mounted in the heater air outlet and increase the temperature of
air to the passenger compartment. Because PTC system is heated by electrical power, high capacity
alternator is required. PTC does not operate during engine cranking, while the battery voltage is lower
than 11 V or during preheating process of glow plugs.
B. Components
HFM (intake air
temperature)
Coolant temperature
sensor
PTC relay 1
D20DTR ECU
PTC relay 2
PTC fuse 1, 2, 3, 40A
PTC heater