Page 386 of 600

2. INSPECTION
1) Alternator Output Test
Item How to check DTC set value / Action
Output
current
B terminal
current
Rotor
coil
resistance
L terminal
voltage
Disconnect the cable connected to the B
terminal on the alternator. Connect one end
of the ammeter to the B terminal and the
other end to the cable connected to the B
terminal.
Measure the maximum output value.
(Maintain the engine speed between 2,500
and 3,000 rpm.)
(Turn the headlamp and all the electrical
switches on.) 1.
2.Pass: If the measured current is 45
A or higher.
Fail: If the measured current is less
than 45 A.
Check the current of the B terminal. -
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Move the gear selector lever to the neutral
position.
Maintain the engine speed at 2,500 rpm
with the vehicle unloaded.
(Turn all the electrical switches off.) 1.
2.Open circuit: If the measured
current is 5 A or higher. -
Disconnect the negative cable from the
battery.
Remove the B terminal and turn off the
ignition switch.
Measure the resistance between the L and
F terminals with an ohmmeter. 1.
2.
3.Pass: If the measured resistance is
Faulty rotor coil or slip ring: If the
measured resistance is less than
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Connect the B terminal wiring.
Measure the voltage with the engine running. 1.
2.Specification: 12.5 V to 14.5 V
Faulty IC regulator or field coil: If
the measured voltage is 14.5 V or
higher. -
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Disconnect the negative battery cable.
Connect the negative cable again after connecting the ammeter. -
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Voltage pattern in actual stepGCU PWM control
4) Operation
Glow plug is installed in the cylinder head. It enhances the cold starting performance and reduces the
exhaust gas during cold starting.
ECU receives the data (engine rpm, coolant temperature, vehicle speed) through CAN lines. Based on the
data, GCU controls the pre-glow, cranking and post-glow. It also checks the glow plugs, and sends the
result to ECU.
Duty control area:
Between 5 and 100%
Frequency: 20 Hz
1.
2.
3.
(1) Temperature/Current Properties of GCU
FETs (similar to transistor) for each cylinder are integrated in GCU. During the pre-glow period, battery
voltage is supplied to the glow plugs directly to heat them rapidly.
After getting the desired temperature by pre-glowing, the temperature is controlled by duty ratio. 1.
2.
3.
Frequency:
20~33Hz
PWM control duty
ratio
- 1st step: 100%
- 2nd step: 35%
- 3rd step: 23%
This describes the voltage supplying types to glow plugs. This shows the supplying voltage and
time by GCU in each step. The 3rd
step is the period to keep the
temperature.
(2) Operation Type of GCU
Page 426 of 600
2. CAUTIONS
Standard pattern of soot accumulation
(1) Abnormal Soot Accumulation (2) Normal Soot Combustion
Cautions to protect the catalyst filter
Use the designated fuel only.
Observe the recommended service intervals of engine oil.
Check the engine oil level frequently and add if necessary.
Do not idle the vehicle unnecessarily.
Do not turn off the engine while the vehicle is running.
Do not shift the gear selector lever to neutral when going downhill.
Do not use improper engine oil or fuel additives.
Do not drive for a long time when the warning lamp is illuminated.
Make sure no flammable material, such as dry grass or tissue paper, contacts with the catalyst filter
while the vehicle is parked.
For the vehicles used in urban traffic, driving on the expressways for more than 1 hour at least once
per week is needed so that the PM inside CDPF isn't collected to one side only. -
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Page 428 of 600
Excessive overload of CDPF (warning lamp illuminated)
If the vehicle is driven at a speed of 5 to 10 km/h for an extended period of time, the soot
accumulated in the CDPF cannot be burned as the CDPF cannot reach the regeneration
temperature. Then, an excessive amount of soot can be accumulated in the CDPF.
This case is much worse than the simple over-load of the CDPF. To inform this to the driver, the
engine warning lamp comes on and the engine power is decreased to protect the system.
To solve this problem, blow soot between the engine and exhaust system several times and erase
the related DTC. Then, check if the same DTC is regenerated again. If so, check the DTC related to
the differential pressure sensor. 1.
2.
3.
Illuminating
Page 468 of 600

D. Bypass control for EGR cooler
Cooler temperature
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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Page 482 of 600
(14) Immobilizer control
A. Overview
The Immobilizer System provides an additional theft deterrent to the vehicle in which it is installed and
prevents it from being started by unauthorized persons. The transponder integrated in the key and the
engine control unit have the same code. When the ignition key with the integrated transponder is turned
to the ON position, the ECU (Engine Control Unit) checks the crypto code of the key and, if correct,
allows the vehicle to start the engine.
For details, refer to Chapter "Immobilizer".
B. Components
Basic components (ignition key system)
D20DTR ECUImmobilizer antennaInstrument cluster
Immobilizer keyStart motor
Page 483 of 600
0000-00
Key approval process
When turning the ignition switch to ON position, the power is supplied to BCM and ECU. ECU
communicate with the immobilizer key to check if it is valid crypto code. If it is valid, ECU start to control
the engine when turning the ignition switch to START position. The system has 10 seconds of valid time-
out period. If the engine does not start in this period, the key approval process should be done again.
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0000-00
3) Guidelines on Engine Service
To prevent personal injuries and vehicle damages that can be caused by mistakes during engine
and unit inspection/repair and to secure optimum engine performance and safety after service
works, basic cautions and service work guidelines that can be easily forgotten during engine
service works are described in.
Cautions before service works
For safe and correct works, you must observe the working procedures and instructions in this
manual. And, use the designated tools as follow:
Engine stand / Heavy duty engine jack
To prevent the engine from starting abruptly, do not allow anybody to get in the vehicle while
servicing in engine compartment.
Before work on engine and electrical equipment, be sure to disconnect battery negative (-)
terminal.
Before service works, be sure to prepare the works by cleaning and aligning work areas.
Do not allow the foreign material get into the fuel injection system.
When removing the engine, use only the safety hook on engine and engine hanger. Do not
support the bottom of oil pan with a jack. -
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Completely drain the engine oil, coolant and fuel from engine before removal.
Before disassembling/assembling the engine components, carefully read the working
procedures in this manual.
Make sure to keep the specified tightening torques during installation.
Clean and properly lubricate the parts before reassembly.
Carefully check that there is not any interference while servicing. -
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