Page 442 of 1082

09-6
Item How to check DTC set value / Action
Output current
B terminal current
Rotor coil
resistance
L terminal voltage
3. INSPECTION
1) Alternator
Output Test ▶
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. -
-
-
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 between 3 and
6Ω.
Faulty rotor coil or slip ring: If
the measured resistance is
less than 3Ω or greater than
6Ω. -
-
Connect the B terminal wiring.
Measure the voltage with the engine
running. 1.
2.
Specification: 12.5V to 14.5V
Faulty IC regulator or field
coil: If the measured voltage
is 14.5V or higher. -
-
Disconnect the negative cable from the battery.
Connect the negative cable again after connecting the ammeter. -
-
Page 468 of 1082
15-31490-00
1. ENGINE DATA LIST
Data Unit Value
Coolant temperature℃ 0.436V (130℃) ~4.896V (-40℃)
Intake air temperature
℃-40~130℃
(varies according to ambient air temperature or
engine mode)
Idle speed rpm700±50(P/N), 600±(D)
Engine load % 18~25%
Mass air flow kg/h 16~25kg/h
Throttle position angle°TA 0° (Full Open) ~ 78° (Close)
Engine torque Nm varies according to engine conditions
Injection time Ms -
Battery voltage V 13.5V~14.1V
Accelerator pedal position
1V 0.3~4.8 V
Accelerator pedal position
2V 0.3~2.4 V
Oxygen sensor mV 0~5 V
OCV (Oil Control Valve) % 0~100%
VIS solenoid valve 1=ON / 0=OFF -
A/C compressor switch
1=ON / 0=OFF-
Full load 1=ON / 0=OFF -
Knocking control 1=ON / 0=OFF -
Brake switch 1=ON / 0=OFF -
Cruise control 1=ON / 0=OFF -
Page 469 of 1082
15-4
Spark plug
OCV (Oil Control
Valve)
Rear oxygen
sensorMCC complete
Knock sensorInjectorOil pressure
switch
Ignition coil
1. MAJOR COMPONENTS
PVC valve
Page 472 of 1082
15-70000-00
Rear oxygen
sensor
2) Components for ECU Input
Coolant temperature
sensorCamshaft position
sensorCrankshaft position
sensor
Front oxygen sensor
Knock sensor
G20DF Engine ECUElectronic throttle
body
Refrigerant pressure sensor
Clutch pedal signal
Blower switch signal
Brake pedal signal
CAN
ABS & ESP
Instrument cluster
TCU -
-
-
Oil pressure
switchOil pressure warning lamp
T-MAP sensor
Page 473 of 1082
15-8
A/C compressorOCV (Oil Control Valve)
3) Components for ECU Output
Start motorInjector
VIS solenoid valve
Purge control solenoid
valve
G20DF Engine ECUIgnition coil
CAN
ABS & ESP unit
BCM
E-coupling unit
EPS
Instrument cluster
SKM
TCU
Diagnostic tool -
-
-
-
-
-
-
-
Cooling fan
module
Page 474 of 1082

15-91490-00
3. ECU CONTROL
1) Functions
ECU receives and analyzes signals from various sensors and then modifies those signals into
permissible voltage levels and analyzes to control respective actuators.
ECU microprocessor calculates injection period and injection timing proper for engine piston speed and
crankshaft angle based on input data and stored specific map to control the engine power and emission
gas.
Output signal of the ECU microprocessor activates the injector solenoid valve to control the fuel injection
period and injection timing; so controls various actuators in response to engine changes.
Auxiliary function of ECU has adopted to reduce emission gas, improve fuel economy and enhance
safety, comforts and conveniences. For example, there are autocruise and immobilizer and adopted
CAN communication to exchange data among electrical systems (automatic T/M and brake system) in
the vehicle fluently. And the diagnostic tool can be used to diagnose vehicle status and defectives.
<00760097008c00990088009b00900095008e0047009b008c00940097008c00990088009b009c0099008c0047009900880095008e008c00470096008d0047006c006a007c00470090009a0047009500960099009400880093009300a000470054005b005700
47009b009600470052005f005c00b6006a004700880095008b> protected from factors like oil,
water and electromagnetism and there should be no mechanical shocks.
2) Control Functions
Controls by operating stages:
To make optimum combustion under every operating stage, ECU should calculate proper injection
volume in each stage by considering various factors.
Starting injection volume control:
During initial starting, injecting fuel volume will be calculated by function of temperature and engine
cranking speed. Starting injection continues from when the ignition switch is turned to ignition
position to till the engine reaches to allowable minimum speed.
Driving mode control:
If the vehicle runs normally, fuel injection volume will be calculated by accelerator pedal travel and
engine rpm and the drive map will be used to match the drivers inputs with optimum engine power. -
-
-
Page 478 of 1082
15-130000-00
Coolant temperature
sensor
4) Ignition System Control
(1) Overview
G20DF engine is equipped with the single ignition system. Each spark plug is operated independently
by the ECU and one ignition coil and spark plug are provided for each cylinder.
(2) Components
Input Components ▶
Crankshaft position
sensorAccelerator pedal position
sensor
Knock sensorCamshaft position
sensorElectronic
throttle body
Output Components ▶
Page 483 of 1082
15-18
6) Cooling Fan Control
(1) Overview of Cooling Fan and A/C Compressor
The cooling system maintains the engine temperature at an efficient level during all engine operating
conditions. The water pump draws the coolant from the radiator. The coolant then circulates through
water jackets in the engine block, the intake manifold, and the cylinder head. When the coolant reaches
the operating temperature of the thermostat, the thermostat opens. The coolant then goes back to the
radiator where it cools. The heat from automatic transaxle is also cooled down through the radiator by
circulating the oil through the oil pump. There are two cooling fans (180W+120W) in G20DF engine. ECU
controls the electric cooling fans with three cooling fan relays to improve the engine torque and air
conditioning performance.
(2) Components
Refrigerant pressure
sensorCoolant temperature
sensorG20DF Engine
ECURelay box in engine
compartment
A/C compressorCooling fan moduleT-MAP sensor