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Mitsubishi Montero (2004+). Manual - part 387

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-3

CHARGING SYSTEM DIAGNOSIS

M1161000700234

TROUBLESHOOTING HINTS

Generator malfunction light dose not go on when the ignition

switch is turned to ON, before the engine starts.

• Check the bulb.

Generator malfunction light dose not switch off after the engine

starts.

• Check the IC voltage regulator inside the generator.

Discharged or overcharged battery.

• Check the IC voltage regulator inside the generator.

The generator malfunction light illuminates dimly.

• Check the diode (inside the combination meter) for a

short-circuit.

TROUBLESHOOTING GUIDE

The charging system troubleshooting guide is shown in the fol-
lowing steps.

STEP 1.
Q: Is the battery in good condition? (Refer to GROUP 54A,

Chassis Electrical

− Battery − On-vehicle Service −

Battery Check

P.54A-5

YES : Go to Step 2 .
NO : Charge or replace the battery.

STEP 2.
Q: Is the generator drive belt in good condition? (Refer to

GROUP 00, General <Body and Chasis>

− Maintenance

Service

− 8. Drive Belt (For Generator, Water Pump and

Power Steering Pump) (Check Condition)

P.00-41

YES : Go to Step 3 .
NO : Adjust the belt tension or replace the belt.

STEP 3.
Q: Does the generator malfunction light come on when the

ignition switch is turned on?
YES : Go to Step 4 .
NO :

• Check the ignition switch. (Refer to GROUP 54A,

Chassis Electrical

− Ignition Switch − Ignition

Switch

− Inspection

P.54A-39

• Check for burnt-out generator malfunction light.

• Check the generator. (Refer to Charging System −

Generator Assembly

− Inspection

P.16-17

• Check the generator malfunction light-related

circuits.

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-4

STEP 4.
Q: Does the generator malfunction light go out after

starting the engine?
YES : Go to Step 5 .
NO : Check the generator (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-17

STEP 5.
Q: Is an oscilloscope available?

YES : Go to Step 6 .
NO : Go to Step 7.

STEP 6.
Q: Dose the oscilloscope show a normal wave pattern?

(Refer to Charging System

− On-vehicle Service − Wave

Pattern Check Using an Oscilloscope

P.16-11

YES : Go to Step 7.
NO : Check the generator. (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-17

STEP 7.

• Engine: 2,500 r/min

• Headlight: ON (high beam)

• Voltage between generator terminal B and the positive bat-

tery terminal
OK: 0.5 V or less

• Voltage between the negative battery terminal and genera-

tor body
OK: 0.5 V or less

Q: Are the generator output line and ground line in good

condition?
YES : Go to Step 8 .
NO : Check the generator output line and ground line.

STEP 8.
Q: Is the output current normal? (Refer to Charging

System

− On-vehicle Service − Output Current Test

P.16-8

YES : Go to Step 9 .
NO : Check the generator (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-17

STEP 9.
Q: Is the regulated voltage normal? (Refer to Charging

System

− On-vehicle Service − Regulated Voltage Test

P.16-10

YES : Go to Step 10 .
NO : Check the generator (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-17

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-5

STEP 10.
Q: Is the voltage drop in the generator output line normal?

YES : Generator is normal. Check other systems.
NO : Check the output line.

SPECIAL TOOL

M1161000600334

TOOL

TOOL NUMBER AND
NAME

SUPERSESSION

APPLICATION

MB991958
Scan tool (MUT-III sub
assembly)

A: MB991824

Vehicle
communication
interface (V.C.I.)

B: MB991827

MUT-III USB cable

C: MB991910

MUT-III main harness
A (Vehicles with CAN
communication
system)

D: MB991911

MUT-III main harness
B (Vehicles without
CAN communication
system)

E: MB991914

MUT-III main harness
C (for Daimler Chrysler
models only)

F: MB991825

MUT-III measurement
adapter

G: MB991826

MUT-III trigger
harness

MB991824-KIT
NOTE: G: MB991826
MUT-III Trigger Harness
is not necessary when
pushing V.C.I. ENTER
key.

Checking of engine idle
speed

MB991910

MB991826

MB991958

MB991911

MB991914

MB991824

MB991827

MB991825

DO NOT USE

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-6

ON-VEHICLE SERVICE

GENERATOR OUTPUT LINE VOLTAGE DROP TEST

M1161000900335

Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

This test determines whether the wiring from the
generator "B" terminal to the positive battery terminal
(including the fusible link) is in good condition or not:

WARNING

Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.

1. Always be sure to check the following before the

test.

• Generator installation

• Generator drive belt tension (Refer to GROUP

00, General <Body and Chasis>

− Maintenance

Service

− 8. Drive Belt (For Generator and Water

Pump, Power Steering Pump) (Check Condition)

P.00-41

• Fusible link

• Abnormal noise from the generator while the

engine is running

2. Turn the ignition switch to the "LOCK" (OFF)

position.

3. Disconnect the negative battery cable.
4. Disconnect the generator output wire from the

generator "B" terminal and connect a DC test
ammeter with a range of 0

− 100 A in series

between the "B" terminal and the disconnected
output wire. (Connect the positive lead of the
ammeter to the "B" terminal, and then connect the
negative lead of the ammeter to the disconnected
output wire.)

MB991519
Generator harness
connector

MIT530
Micrd 530 charging
system tester.

Checking of generator
("S" terminal voltage)

TOOL

TOOL NUMBER AND
NAME

SUPERSESSION

APPLICATION

AKX00185

GENERATOR

AMMETER

VOLTMETER
(DIGITAL-TYPE)

BATTERY

–

"B"TERMINAL

Content .. 385 386 387 388 ..