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4) Basic Inspection
(1) Horn operation
Listen for the horn sound when pressing the horn pad on the steering wheel. -
(2) Brake operation
Check if there is any abnormal noise, unusually long braking distance, or uneven braking force. If the
brake warning lamp does not go out even after starting the engien or are flashing during driving,
have the brake system checked immediately.
Check the brake pipes and hoses for connection, oil leak, crack or interference after changing the
position of tires. When replacing the tires, check the brake disc for surface condition and wear.
Check the parking brake cable and brake operation. Shorten the checking interval if the parking
brake is used frequently. -
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(3) Exhaust system
Be aware to any changes in sound or smell from the exhaust system. These may be caused by leak or
overheat. Have the exhaust system checked and repaired immediately.
Inspect the exhaust system including catalytic converter. Inspect all the components and body frame
near the exhaust system. -
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(4) Tires
Unusual vibration of the steering wheel and seats or pulling to one side on the straight and level roads
may indicates the uneven tire inflation pressure or poor wheel balance. -
(5) Steering and suspension system
Inspect the front and rear suspension and the steering system for damage, looseness or missing
parts, signs of wear or lack of lubrication. Inspect the power steering line and the hoses for
connection, leak, crack and chafing. Inspect the drive axle boot and seals for damage, tear or leak.
Replace or repair the system if necessary. -
(6) Engine oil
Check the oil level when the engine is still warm and add the specified engine oil if necessary. -
(7) Coolant
Check the coolant level in the coolant reservoir, coolant conditions (contamination, foreign material),
and hoses for damage and leak. Replace or add the Ssangyong genuine coolant, if needed. -
(8) Engine drive belt
Check all drive belts on the engine for wear, crack and looseness. Retighten or replace the belt, if
needed. -
Page 254 of 1336

The engine ECU calculates the accelerator pedal based on the input signals from various sensors, and
controls the overall operation of the vehicle.
The ECU receives the signals from various sensor through data line, and performs effective air-fuel ratio
control based on these signals.
The crankshaft speed (position) sensor measures the engine speed, and the camshaft speed (position)
sensor determines the order of injections, and the ECU detects the amount of the accelerator pedal
depressed (driver's will) by receiving the electrical signals from the accelerator pedal sensor.
The mass air flow sensor detects the volume of intake air and sends the value to the ECU.
The major function of the ECU is controlling air-fuel ratio to reduce the emission level (EGR valve control)
by detecting instantaneous air flow change with the signals from the mass air flow sensor.
Also, the ECU uses the signals from the coolant temperature & air temperature sensors, booster pressure
sensor, atmospheric pressure sensor to: a) determine injection starting point and set value for pilot
injection, and b) deal with various operations and variable conditions.
Page 299 of 1336

2. INSPECTION
Possible Cause Action
Coolant level
is too low- Leak from the radiator
- Leak from the auxiliary reservoir
- Leak from the heater core- Replace the radiator
- Replace the auxiliary reservoir
- Replace the heater
- Leak from the coolant hose connections
- Damaged coolant hose- Reconnect the hose or replace
the clamp
- Replace the hose
- Leak from the water pump gasket
- Leak from the water pump internal seal- Replace the gasket
- Replace the water pump
- Leak from the water inlet cap
- Leak from the thermostat housing- Replace the water inlet cap
gasket
- Replace the thermostat sealing
- Incorrect tightening torque of the
cylinder head bolts
- Damaged cylinder head gasket- Tighten the bolts to the specified
torque
- Replace the cylinder head
gasket
Coolant
temperature is
too high- Coolant leakage (Coolant level is low)
- Improper coolant mixture ratio
- Kinked coolant hose- Add coolant
- Check the coolant concentration
(Anti-freeze)
- Repair or replace the hose
- Defective thermostat
- Defective water pump
- Defective radiator
- Defective auxiliary reservoir or tank cap- Replace the thermostat
- Replace the water pump
- Replace the radiator
- Replace the auxiliary reservoir
or tank cap
- Cracks on the cylinder block or cylinder
head
- Clogged coolant passages in the
cylinder block or cylinder head- Replace cylinder block or
cylinder head
- Clean the coolant passage
- Clogged radiator core - Clean the radiator core
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or faulty
wiring- Replace the sensor or repair the
related wiring
Coolant
temperature is
too low- Thermostat is stuck open - Replace the thermostat
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or faulty
wiring- Replace the sensor or repair the
related wiring
Page 300 of 1336
0000-00
1) Coolant Level Check
Park the vehicle on level ground and apply the parking brake. Stop the engine and wait until it is
cooled down.
The coolant level should be between the MAX and MIN mark on the coolant reservoir.1.
2.
Scalding hot coolant and steam could be blown out under pressure, which could cause serious injury.
Never remove the coolant reservoir cap when the engine and radiator are hot.
Avoid any direct contact of the coolant to the painted body of the vehicle. -
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MAX
MIN
Page 301 of 1336
2) Leak Test
Release the pressure in the system by
loosening the pressure cap of the coolant
reservoir slightly. Then, remove the pressure
cap completely. 1.
Never open the cap until the coolant
prevent any burn.
Add the coolant so that the coolant level is
between MAX and MIN mark on the coolant
auxiliary tank.
Connect the tester to the tank filler and
apply pressure (1.4 bar).
Check all the coolant hoses, pipes and
connections for leaks when the pressure of
the tester drops, and replace or tighten, if
necessary. 2.
3.
4.
3) Thermostat
Immerse the thermostat into the water. Heat the
water and check the valve opening temperature.
Valve opening
temperature
Page 322 of 1336
1413-00
1. OVERVIEW
The pre-heating system for D20DTF 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 plugGlow plug control unit
(GCU)
Glow indicatorEngine ECU (D20DTF)
Page 395 of 1336
T-MAP sensor
D20DTF ECUOxygen sensor
Electronic
throttle bodyHFM sensor
(intake air temp.)
Coolant
temp.sensor
E-EGR valve
Crankshaft posi.
sensor
Accelerator
pedal
E-EGR cooler
(5) 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.
The major difference with the previous EURO 4 type, is that the DC motor with improved response rate
according to the EURO 5 regulation. The solenoid type actuator is used in the conventional model, but in
this new model, the DC motor type actuator with improved response rate is adopted. Also the hall senso
r
which provides a more stabilized signal than the potentiometer, and the EGR bypass flap which
improves engine warming up efficiency are also used. The HFM sensor and the position sensor are
used to feedback the amount of EGR for both EURO 4 and EURO 5.
b. Components
Page 397 of 1336

d. Bypass control for EGR cooler
1. Cooler temperature
2. Exhaust gas temperature
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). -
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