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Alternator
The alternator charges the battery and
supplies power to each electric unit by
converting the mechanical energy to the
electrical energy.
1. SYSTEM DESCRIPTION
1) Overview
The charge system is designed to supply electrical energy to the vehicle while driving, and supplies a
constant direct current voltage by converting mechanical rotational movement to electrical energy.
The voltage regulator on the back of the alternator controls the generated voltage in all rotating ranges
and adjusts the system voltage according to the electric load and ambient temperature change.
2) System Layout (Locations)
Battery
It converts the chemical energy to the
electrical energy and supplies power to the
corresponding electric units when starting the
engine.
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Alternator (140 A)Alternator (120 A)
2) Charging
The alternator uses a new regulator which has three diodes. It consists of the delta stator, rectifier bridge,
slip ring and brush.
Charging time according to vehicle conditions and environment
Specification: Charging a fully depleted high-
capacity battery takes twice or more as long as
charging a fully depleted battery for small
vehicles.
Temperature: The lower the temperature is, the
longer the time taken to charge the battery.
When connecting the battery charger to the cold
battery, the amount of current the battery can
accept initially is very small. As the battery gets
warmer, it can accept more current.
Charging capacity: Charging a battery with a low-capacity charger takes longer time than charging with
a high-capacity charger.
Charging status: Charging a fully depleted battery takes twice or more as long as charging a half-
depleted battery. Since the electrolyte in a fully depleted battery consists of nearly pure water and
conductor, only a very small amount of current can be accepted by the battery initially. The charging
current increases as the amount of acids in the electrolyte is increased by the charging current.
3) Output Characteristics
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1413-00
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
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(3) Operation
Pre-Glow: Step 1
If normal communication with the ECU is established 2 seconds after the power is supplied to the IGN
terminal from the battery, the GCU supplies the battery power to raise the temperature of the glow plug
- The time for pre-heating is controlled by the ECU.
Input power VB(V) Arrival time T1(s)
68.27
75.8
84.1
93.15
10 2.4
11 1.95
1.9
If the input power (VB) is 11.5 V or less, the GCU supplies the battery power for arrival time (T1).
If the input power (VB) is greater than 11.5 V, the GCU supplies the voltage of 11.5 V for arrival time
(T1). -
-
The time for pre-heating by coolant temperature can vary slightly depending on e.g. other vehicle
operation elements.
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2. TROUBLESHOOTING
ProblemAction
Engine will not crankLow battery voltage Charge or replace
Loose, corroded or damaged battery cable
Repair or replace
Faulty starter or open circuit
Faulty ignition switch or blown fuse Repair or replace
Poor engine ground Repair
Engine cranks too
slowLow battery voltage Charge or replace
Loose, corroded or damaged battery cable
Repair or replace
Faulty starter
Starter does not
stopFaulty starter
Faulty ignition switch Replace
Engine cranks
normally, but does
not startBroken pinion gear or faulty starter
Replace the starter
Broken flywheel ring gear Replace
Open circuit Repair
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0000-00
1. ENGINE DATA LIST
Data Unit Value
Coolant temperature
Intake air temperature
temperature or engine mode)
Idle speed rpm
Engine load % 18~25%
Mass air flow kg/h 16 to 25 kg/h
Throttle position angle
Engine torque Nm varies by engine conditions
Injection time ms 3 to 5ms
Battery voltage V 13.5 V to 14.1 V
Accelerator pedal position 1 V 0.4. to 4.8V
Accelerator pedal position 2 V 0.2 to 2.4 V
Throttle position 1 V 0.3 to 4.6 V
Throttle position 2 V 0.3 to 4.6 V
Oxygen sensor mV 0 to 5 V
A/C compressor switch 1=ON / 0=OFF -
Full load 1=ON / 0=OFF -
Gear selection (A/T) 1=ON / 0=OFF -
Knocking control 1=ON / 0=OFF -
Brake switch 1=ON / 0=OFF -
Cruise control 1=ON / 0=OFF -
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C. Idle Speed Controller
The idle speed controller consists of 2 principal modules:
The first module determines the required idle speed according to:
* The operating conditions of the engine (coolant temperature, gear engaged)
* Any activation of the electrical consumers (power steering, air conditioning, others)
* The battery voltage
* The presence of any faults liable to interface with the rail pressure control or the injection control. In
this case, increase the idle speed to prevent the engine from stalling.
The second module is responsible for providing closed loop control of the engine's idle speed by
adapting the minimum fuel according to the difference between the required idle speed and the
engine speed. -
-
D. Flow Limitation
The flow limitation strategy is based on the following strategies:
The flow limitation depending on the filling of the engine with air is determined according to the
engine speed and the air flow. This limitation allows smoke emissions to be reduced during
stabilized running.
The flow limitation depending on the atmospheric pressure is determined according to the engine
speed and the atmospheric pressure. It allows smoke emissions to be reduced when driving at
altitude.
The full load flow curve is determined according to the gear engaged and the engine speed. It
allows the maximum torque delivered by the engine to be limited.
A performance limitation is introduced if faults liable to upset the rail pressure control or the
injection control are detected by the system. In this case, and depending on the gravity of the fault,
the system activates: -
-
-
-
Reduced fuel logic 1: Guarantees 75 % of the performance without limiting the engine speed.
Reduced fuel logic 2: Guarantees 50 % of the performance with the engine speed limited to
3,000 rpm.
Reduce fuel logic 3: Limits the engine speed to 2,000 rpm.
The system chooses the lowest of all values.
A correction depending on the coolant temperature is added to the flow limitation. This correction makes
it possible to reduce the mechanical stresses while the engine is warming up.
The correction is determined according to the coolant temperature, the engine speed and the time which
has passed since starting.
E. Superchager Flow Demand
The supercharge flow is calculated according to the engine speed and the coolant temperature. A
correction depending on the air temperature and the atmospheric pressure is made in order to increase
the supercharge flow during cold starts. It is possible to alter the supercharge flow value by adding a flow
offset with the aid of the diagnostic tool
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0000-00
(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
sensorPTC heaterD20DTR ECU
PTC 1 relay
PTC 2 relay
PTC 3 relay
PTC Fuse 3 (40A)PTC Fuse 2 (40A)PTC Fuse 1(40A)
Relay box in engine compartment