Mitsubishi Montero (2002-2004). Manual - part 1088

STARTING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-25

INSPECTION

M1162001300049

.

COMMUTATOR CHECK
1. Place the armature on a pair of V-blocks, and check the 

deflection by using a dial gauge.

Standard value: 0.05 mm (0.002 inch)
Limit: 0.1 mm (0.004 inch)

2. Check the outer diameter of the commutator.

Standard value: 29.4 mm (1.16 inches)
Minimum limit: 28.8 mm (1.13 inches)

3. Check the depth of the undercut between segments.

Standard value: 0.5 mm (0.02 inch)
Minimum limit: 0.2 mm (0.008 inch)

.

BRUSH CHECK
1. Check the brush for roughness of the surface that contacts 

the commutator and check the brush length.Replace the 
brush holder if this measurement exceeds the limit.

Minimum limit: 7.0 mm (0.28 inch)

2. .In the case contacting surface has been corrected or the 

brush has been replaced, correct the contacting surface by 
winding sandpaper around the commutator

.

AKX00373

AKX00374

AKX00375

SEGMENT

UNDERCUT

MICA

AB

AK101390

LIMIT LENGTH

AB

STARTING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-26

OVERRUNNING CLUTCH CHECK
1. While holding the clutch housing, rotate the pinion. The drive 

pinion should rotate smoothly in one direction, but should 
not rotate in opposite direction. If the clutch does not 
function properly, replace the overrunning clutch assembly.

2. Inspect the pinion for wear or burrs. If the pinion is worn or 

burred, replace the overrunning clutch assembly. If the 
pinion is damaged, also inspect the ring gear for wear or 
burrs.

.

FRONT AND REAR BRACKET BUSHING CHECK
Inspect the bushing for wear or burrs. If the bushing is worn or 
burred, replace the front bracket assembly or rear bracket 
assembly.

.

ARMATURE CHECK
1. Check that the armature coil is not grounded.
2. Place the armature in a growler.
3. Hold a thin steel blade parallel and just above while rotating 

the armature slowly in the growler. A shorted armature will 
cause a blade to vibrate and be attracted to the core. 
Replace the shorted armature.

4. Check the insulation between the armature coil cores and 

the commutator segments. They are normal if there is no 
continuity.

5. Check for continuity between the segments. The condition is 

normal if there is continuity.

AKX00378

FREE

LOCK

AB

AKX00379

GROWLER

AB

AKX00380

AKX00381

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-27

IGNITION SYSTEM

GENERAL DESCRIPTION

M1163000100186

This system is provided with three ignition coils (A, B 
and C) with built-in three ignition power transistors 
for the number 1 and number 4 cylinders, number 2 
and number 5 cylinders and number 3 and number 6 
cylinders respectively. 
Interruption of the primary current flowing in the pri-
mary side of ignition coil A generates a high voltage 
in the secondary side of ignition coil A.
The high voltage thus generated is applied to the 
spark plugs of number 1 and number 4 cylinders to 
generate sparks. At the time that the sparks are gen-
erated at both spark plugs, if one cylinder is at the 
compression stroke, the other cylinder is at the 
exhaust stroke, so that ignition of the compressed 
air/fuel mixture occurs only for the cylinder which is 
at the compression stroke.
In the same way, when the primary current flowing in 
ignition coil B is interrupted, the high voltage thus 
generated is applied to the spark plugs of number 2 
and number 5 cylinders, and when the primary cur-
rent flowing in ignition coil C is interrupted, the high 
voltage thus generated is applied to the spark plugs 
of number 3 and number 6 cylinders. 

The engine control module controls the three ignition 
power transistors to turn them alternately ON and 
OFF. This causes the primary currents in the ignition 
coils (A, B and C) to be alternately interrupted and 
allowed to flow to fire the cylinders in the order 1-2-3-
4-5-6.
The engine control unit determines which ignition coil 
should be controlled by means of the signals from 
the camshaft position sensor which is incorporated in 
the camshaft and from the crankshaft position sensor 
which is incorporated in the crankshaft. 
It also detects the crankshaft position to provide igni-
tion at the most appropriate timing in response to the 
engine operation conditions.
When the engine is cold or operated at high alti-
tudes, the ignition timing is slightly advanced to pro-
vide optimum performance.

AK200804

PCM

TO TACHOMETER

IGNITION COIL A

IGNITION COIL B

IGNITION COIL C

IGNITION
SWITCH

BATTERY

SPARK PLUGS

CYLINDER NO.

3

6

5

2

4

1

AB

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-28

SPECIAL TOOLS

M1163000600028

ON-VEHICLE SERVICE

SPARK PLUG CABLE TEST

M1163000900029

WARNING

Wear rubber gloves while performing this test.

1. Disconnect, one at a time, each of the spark plug cables 

while the engine is idling to check whether the engine's 
running performance changes or not.

2. If the engine performance does not change, check the 

resistance of the spark plug cable, and check the spark plug 
itself.

SPARK PLUG TEST

M1163001500024

1. Remove the spark plug and connect to the spark plug cable.

TOOL

TOOL NUMBER AND 
NAME

SUPERSESSION

APPLICATION

MB991348
Test harness set

MB991348-01

Inspection of ignition 
primary voltage (ignition 
power transistor 
connection)

MD998773
Knock sensor wrench

−

Knock sensor removal 
and installation

MB991348

AKX00431

SPARK PLUG CABLE

AB

AKX00432

SPARK PLUG

AB