Page 278 of 796
08-91520-00
Coolant temperature sensor
Measures the coolant
temperature and sends the
result to the engine ECU.
Electric fan
Circulates the fresh air forcibly to exchange heat
with the radiator core fin.
Radiator
Releases heat through fins and cools down the hot
coolant as the coolant passes through the tube of the
radiator core.
MT - 400W , AT- 600W
Page 280 of 796

09-4
2. INSPECTION
1) Alternator Output Test
Item How to check DTC set value / Action
Output
current
B terminal
current
Rotor
coil
resistance
D 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. -
-
-
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 6 Ω.
Faulty rotor coil or slip ring: If the
measured resistance is less than 3
Ω or greater than 6 Ω. -
-
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. -
-
Disconnect the negative battery cable.
Connect the negative cable again after connecting the ammeter. -
-
Page 281 of 796

09-51451-01
2) Troubleshooting for Alternator
Item Cause Action
Overcharged
batteryDefective alternator voltage regulator Replace the alternator
Defective voltage detection wiring Replace the alternator
Defective voltage detection wiring Repair or replace
Discharged battery Loose alternator drive belt Adjust 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 the alternator
Terminated battery Replace the battery
Defective ground Repair
Charge warning
lamp does not
come on when
turning on ignition
switch with engine
stoppedDefective alternator voltage regulator Replace the alternator
Open circuit in charge warning lamp,
fuse or wiringReplace or repair the charge
warning lamp or fuse
Defective ignition switch Replace the ignition switch
Defective ground of alternator circuit Repair
Charge warning
lamp is not turned
off after starting
engineDefective alternator voltage regulator Replace the alternator
Corroded or worn battery cable Repair or replace the battery cable
Loose alternator drive bel Replace the batteryAdjust the belt
tension or replace the belt
Defective wiring harness Repair or replace
Warning lamp does
not go off even
after starting the
engineCorrosion or damage of
battery cableRepair or replace the
battery cable
Loose alternator drive belt Adjust the belt tension or
replace the belt
Defective wiring harness Repair or replace
Overcharged
batteryDefective voltage regulator of alternator Replace the alternator
Defective voltage detecting wiring Repair or replace
Page 284 of 796

09-8
(3) Starting with jumper cable
If the battery is weak or terminated, the battery from another vehicle can be used with jumper
cables to start the engine.
Connecting order ▶
The positive (+) terminal of the discharged battery
The positive (+) terminal of the booster battery
The negative (-) terminal of the booster battery
Connect one end of the other jumper cable to the body of the discharged vehicle, such as the
engine block or a front towing hook. 1.
2.
3.
4.
Starting ▶
Prepare a set of jumper cables.
Place another vehicle that has the same 12 V of power near to the discharged vehicle.
Switch off all electrical accessories for the discharged vehicle.
Apply the parking brake and shift the transaxle to the P position (automatic transaxle) or neutral (N)
position (manual transaxle).
Connect the jumper cables.
Try to start the discharged vehicle while accelerating the engine rpm in the booster vehicle.
Attempt to start the engine with the discharged battery.
After starting the engine, carefully disconnect the jumper cables in the reverse sequence of
connection. 1.
2.
3.
4.
5.
6.
7.
8.
Page 286 of 796
09-10
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.
Page 291 of 796
10-4
1. OVERVIEW
The pre-heating system for D20DTR 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 plug
Engine ECU (D20DTR)Glow indicator
Glow plug control unit
(GCU)
Page 294 of 796
10-71413-00
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.
(1) Temperature/Current Properties of GCU
GCU increases the temperature of glow plug very rapidly (approx. 2 seconds up to
1000°C)
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. Step 1:
Step 2 & 3:
Step 4:
This shows the supplying voltage and time by GCU in each step. The step 4 is the period to keep
the temperature. -Step 1: I1
Step 2: I2
Step 3: I3
Step 4: I4
Page 299 of 796
11-4
2. TROUBLESHOOTING
Problem Possible Cause Action
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 fuseRepair or replace
Poor engine ground Repair
Engine cranks too
slowLow battery voltage Charge or replac
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