Page 348 of 1082
01-24
8. ELECTRIC SYSTEM
Start motor assemblyBattery
Converts the chemical energy to the
electrical energy and supplies power to the
corresponding electric units when starting
the engine.
B+ wiringAlternator
Charges the battery and supplies power to
each electric unit by converting the
mechanical energy to the electrical energy.
Page 352 of 1082

02-6
3. GUIDELINES ON ENGINE SERVICE
G20DF engine is for FF (Front Engine Front Drive) type vehicle. Therefore, there are some deferent
maintenance and repair works compared to the engine for FR (Front Engine Rear Drive) type vehicle.
For safe and correct works, you must observe the working procedures and instructions in this manual.
And, use the designated tools as follow:
: Power train mounting stand / Engine hanger / Engine stand / Heavy duty engine jack.
Cautions before service works ▶
G20DF engine is FF (Front Engine Front Drive) type engine, and the engine and transmission are
integrated in a same module. Remember that there are many differences compared to
conventional engine in FR (Front Engine Rear Drive) type SUV vehicle.
To remove the engine, use the dedicated equipments such as engine jack, transmission jack,
engine stand and engine crane (1 ton).
To prevent the engine from abruptly starting during service in engine compartment, never allow
anybody to stay in the vehicle.
Make sure to disconnect the negative (-) cable from the battery to prevent any damage to electric
systems.
Make sure to clean the working area and to prepare the necessary tools before service works.
Always place the ignition switch to OFF position if not required. Otherwise, there could be
unexpected damage to electric devices or personal injuries due to short-circuit..
To prevent the foreign material from entering into the fuel injection system, completely seal the
inlets of HP pump, fuel hoses and high pressure pipes.
Do not remove the engine while supporting the oil pan with a jack. -
-
-
-
-
-
-
Lifting up the vehicle ▶
Before lifting up the vehicle with a lift, correctly support the lifting points.
To prevent the vehicle from rolling down, put the chocks under the tires (when using a 4-post lift).
Make sure to support the correct lifting points (when using a 2-post lift). -
-
-
Page 354 of 1082

02-8
Fuel and engine oil system ▶
The engine oil and fuel damages the painted surfaces and rubber material of the vehicle.
Disconnect the negative cable from the battery before servicing the fuel system, and prepare the
service plug grip.
When working with the fuel or oil systems in enclosed area, always keep the working area well-
ventilated and never allow anybody to smoke.
Do not allow the gasoline to contact to rubber or leather parts.
Carefully separate the pipe between high pressure fuel pump and fuel injector so that any fuel can
be spilled out.
Fully release the pressure from the fuel system before removing any parts of fuel system.
To release the fuel pressure in high pressure line, let the engine fully cool down.
Gaskets and seals on the fuel and oil systems should be replaced with new ones. All bolts and nuts
should be tightened as specified.
Prolonged exposure to the engine oil make cause a skin cancer or an irritation.
Used engine cotains the hazardous material that may cause the skin cancer. Do not allow the used
engine to make contact with your skin.
Make sure to wear the protection gloves and goggle when handling the engine oil. If contact
happens, rinse affected areas immediately with plenty of water. Do not wash it with gasoline or
solvent. If irritation persists, consult a doctor.
Improperly disposed engine oil can pollute the environment. Dispose the used engine oil and oil
filter in accordance with local environmental regulations.
Make sure to check the connections for leak after installation. -
-
-
-
-
-
-
-
-
-
-
-
Electric devices ▶
To prevent any damage to electric systems, make sure to disconnect the negative (-) cable from the
battery and place the ignition switch to OFF position before servicing.
Use only the specified parts with same ratings when replacing the electric devices. Check the
grounds and connections for looseness. -
- Extraordinary care should be taken when servicing the electric systems. Currently, the engine uses a lot
of electric devices. Short circuit and poor contact may cause the low engine performance, incomplete
combustion and other abnormalities.
Page 439 of 1082
09-31452-01
1. SPECIFICATION
Unit Description Specification
AlternatorType HPS EPS
Crankshaft pulley : Alternator pulley 1 : 2.66
Normal output
(idle/2200rpm)70/140A←
Regulator voltage 12V←
BrushLength 12.5mm←
Wear limit 7.0mm←
BatteryType MF←
Capacity 90AH←
Page 441 of 1082
09-51452-01
2) Battery
Battery assembly
Clamp - Battery
Bolt
Cable assembly - Cable positive
Cable assembly - Battery ground
Bolt - Earth
Cap - Terminal
Connector - Battery 1.
2.
3.
5.
6.
8.
9.
10.Nut
Nut
Cab - Earth
Box assembly - Battery sub
Fuse - MID 80A
Clamp - Battery cable
Grommet - Ring terminal
Grommet - Ring terminal 17.
18.
20.
21.
22.
23.
24.
25.
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 443 of 1082

09-71452-01
Troubleshooting ▶
Item Cause Action
Overcharged batteryDefective alternator voltage regulator Replace
Defective voltage detection wiring Repair or replace
Discharged batteryLoose alternator drive belt
just the belt tension or
replace
Poor connection of related circuit or open
circuitRetighten the loose
connection or repair
open circuit
Defective alternator voltage regulator Replace
Terminated battery Replace
Defective ground Repair
Charge warning lamp does
not come on when turning on
ignition switch with engine
stoppedDefective alternator voltage regulator Replace
Open circuit in charge warning lamp, fuse
or wiringReplace or repair the
charge warning lamp or
fuse
Defective ignition switch Replace
Defective ground of alternator circuit Repair
Charge warning lamp does
not go off after starting
engineDefective alternator voltage regulator Replace
Corroded or worn battery cable Repair or replace
Loose alternator drive belt
Adjust the belt tension or
replace the belt
Defective wiring harness Repair or replace
Page 444 of 1082
09-8
2) Battery
Inspection ▶