Mitsubishi Montero (2004+). Manual — part 394

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-31

SPARK PLUG TEST

M1163001500024

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

2. Ground the spark plug outer electrode (body), and crank the

engine.
Check that there is an electrical discharge between the
electrodes at this time.

IGNITION COIL CHECK

M1163001200153

Check by the following procedure, and replace the coil if there
is a malfunction.

.

SECONDARY COIL RESISTANCE CHECK
Measure the resistance between the high-voltage terminals of
the ignition coil.

Standard value: 8.5

− 11.5 kΩ

.

AKX00432

SPARK PLUG

AB

AKX00277

DEFECTIVE INSULATION

DEFECTIVE INSULATION

DEFECTIVE
INSULATION

GOOD

AB

AKX01264

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-32

PRIMARY COIL AND IGNITION POWER TRANSISTOR
CONTINUITY CHECK

NOTE: An analog-type ohmmeter should be used.
NOTE: Connect the negative probe of the ohmmeter to termi-
nal 1.

CAUTION

This test must be performed quickly (in less than 10 sec-
onds) to prevent coil from burning and ignition power tran-
sistor from breaking.
1. Connect and disconnect 1.5 V battery between terminals 2

and 3, and observe the ohmmeter whether there is
continuity or not.

2. If results do not agree with the table below, replace the

primary coil and ignition power transistor assembly.

SPARK PLUG CABLE RESISTANCE CHECK

M1163001400083

Measure the resistance of the all spark plug leads.
1. Check the cap and coating for cracks.
2. Measure the resistance.

Limit: 19 k

Ω

AKX01265AB

1.5 V

1 2 3

+

–

1.5 V POWER SUPPLY
BETWEEN 2

− 3

CONTINUITY BETWEEN
1

− 2

Current flowing

Yes

Current not flowing

No

AKX00382

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-33

SPARK PLUG CHECK AND CLEANING

M1163004300212

CAUTION

• Do not attempt to adjust the gap of the iridium plug.
• Cleaning of the iridium plug may result in damage to

the iridium and platinum tips. Therefore, if carbon
deposits must be removed, use a plug cleaner and
complete cleaning within 20 seconds to protect the
electrode. Do not use a wire brush.

Check the plug gap and replace if the limit is exceeded.

Standard value: 0.7

− 0.8 mm (0.028 − 0.031 inch)

Limit: 1.0 mm (0.039 inch)

CAMSHAFT POSITION SENSOR CHECK

M1163004400242

Refer to GROUP 13A, Multiport Fuel Injection (MFI)

− Multiport

Fuel Injection (MFI) Diagnosis

− Diagnostic Trouble Code Pro-

cedures

− DTC P0340 : Camshaft Position Sensor Circuit

P.13A-486

.

CRANKSHAFT POSITION SENSOR CHECK

M1163004500302

Refer to GROUP 13A, Multiport Fuel Injection (MFI)

− Multiport

Fuel Injection (MFI) Diagnosis

− Diagnostic Trouble Code Pro-

cedures

− DTC P0335 : Crankshaft Position Sensor Circuit

P.13A-467

.

IGNITION SECONDARY VOLTAGE WAVE
PATTERN CHECK USING AN OSCILLOSCOPE

M1163001700200

.

MEASUREMENT METHOD
1. Clamp the spark plug cable (Number 1, 3 or 5) with the

secondary pickup.
NOTE: Because of the two-cylinder simultaneous ignition
system, the waves for two cylinders in each group appear
during wave observation. However, wave observation is car-
ried out for the cylinder (Number 1, 3 or 5) with the spark
plug cable which has been clamped by the secondary
pickup.
NOTE: Identification of which cylinder wave pattern is dis-
played can be difficult, but the wave pattern of the cylinder
which is clamped by the secondary pickup will be stable, so
this can be used as a reference for identification.

2. Clamp the spark plug cable (Number 1, 3 or 5) with the

trigger pickup.
NOTE: Clamp the same spark plug cable as the one which
has been clamped by the secondary pickup.

.

AKX01327AB

IRIDIUM
TIP

PLATINUM
TIP

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-34

STANDARD WAVEPATTERN

Observation Conditions

FUNCTION

SECONDARY

Pattern height

High (or low)

Pattern selector

Raster

Engine revolutions

Curb idle speed

Observation Conditions (Only pattern selector below
changes from the above conditions.)

Pattern selector

Display

AKX00278

kV

0

SECONDARY

IGNITION

VOLTAGE

WAVE PATTERN

IGNITION VOLTAGE
(POINT D)

SPARK LINE (POINT A)

DWELL SECTION

WAVE DAMPING REDUCTION SECTION (POINT B)

POINT C

TIME

AB