Mitsubishi Galant 9G. Manual - part 360

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-36

IGNITION SYSTEM

GENERAL DESCRIPTION

M1163000100528

<2.4L ENGINE>

This system is provided with four ignition coils with 
built-in ignition power transistors for each of the cylin-
ders. 
Interruption of the primary current flowing in the pri-
mary side of ignition coil generates a high voltage in 
the secondary side of ignition coil.
The powertrain control module (PCM) controls the 
four ignition power transistors to turn them alter-
nately ON and OFF. This causes the primary cur-
rents in the ignition coils to be alternately interrupted 
and allowed to flow to fire the cylinders in the order 
1-3-4-2.

The PCM 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.

<3.8L ENGINE>

This system is provided with six ignition coils with 
built-in ignition power transistors for each of the cylin-
ders. 
Interruption of the primary current flowing in the pri-
mary side of ignition coil generates a high voltage in 
the secondary side of ignition coil.
The powertrain control module (PCM) controls the 
three ignition power transistors to turn them alter-
nately ON and OFF. This causes the primary cur-
rents in the ignition coils to be alternately interrupted 
and allowed to flow to fire the cylinders in the order 
1-2-3-4-5-6.

The PCM 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.

AK304112AB

PCM

IGNITION SWITCH

IGNITION COIL

SPARK PLUG

CYLINDER NO.

BATTERY

1

2

3

4

INTAKE AIR TEMPERATURE SENSOR

CAMSHAFT POSITION SENSOR

CRANKSHAFT POSITION SENSOR

TRANSMISSION RANGE SWITCH

IGNITION SWITCH-ST

KNOCK SENSOR 

ENGINE COOLANT TEMPERATURE SENSOR

MASS AIRFLOW SENSOR

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-37

SPECIAL TOOLS

M1163000600073

ON-VEHICLE SERVICE

KNOCK CONTROL SYSTEM CHECK

M1163001800081

Check the knock sensor circuit if diagnostic trouble code, No. 
P0325 is shown.

<2.4L ENGINE>

Refer to GROUP 13A, Multiport Fuel Injection (MFI) <2.4L 
Engine> 

− Multiport Fuel Injection (MFI) Diagnosis − Diagnostic 

Trouble Code Procedures 

− DTC P0325 : Knock Sensor Circuit 

P.13A-540

.

<3.8L ENGINE>

Refer to GROUP 13B, Multiport Fuel Injection (MFI) <3.8L 
Engine> 

− Multiport Fuel Injection (MFI) Diagnosis − Diagnostic 

Trouble Code Procedures 

− DTC P0325 : Knock Sensor Circuit 

P.13B-596

.

AK400831AB

MASS AIRFLOW 
SENSOR

PCM

IGNITION 
SWITCH 

IGNITION 
COIL

SPARK PLUG

CYLINDER NO.

BATTERY

1

2

3

4

5

6

INTAKE AIR 
TEMPERATURE SENSOR

ENGINE COOLANT 
TEMPERATURE SENSOR

CAMSHAFT POSITION
SENSOR

CRANKSHAFT POSITION
SENSOR

TRANSMISSION RANGE

 

SWTCH

IGNITION SWITCH-ST

KNOCK SENSOR

TOOL

TOOL NUMBER AND 
NAME

SUPERSESSION

APPLICATION

MD998773
Knock sensor wrench

MD998773-01

Knock sensor removal 
and installation

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-38

IGNITION COIL CHECK 

M1163001200380

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

.

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 4.5 

− 9.0 V battery between 

terminal No. 2 and No. 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.

.

SECONDARY COIL CHECK

NOTE: It is impossible to check the secondary coil through the 
continuity check as a diode is integrated in the secondary coil 
circuit of this ignition coil. Accordingly, check the secondary coil 
in the following procedure. 
1. Disconnect the ignition coil connector.
2. Remove the ignition coil and install a new spark plug to the 

ignition coil. 

3. Connect the ignition coil connector.
4. Ground the side electrode of the spark plug and crank the 

engine.

5. Check that spark is produced between the electrodes of the 

spark plug.

AK303638 AB

4.5 – 9.0 V

1 2 3

+

–

4.5 

− 9.0 V POWER SUPPLY

BETWEEN 2 

− 3

CONTINUITY BETWEEN 
1 

− 2

Current flowing

Yes

Current not flowing

No

IGNITION SYSTEM

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ENGINE ELECTRICAL

16-39

6. If no spark plug is produced, replace the ignition coil with a 

new one and recheck.

7. If spark is produced with the new ignition coil, replace the 

old one as it is faulty. If no spark is produced again, the 
ignition circuit is suspected as faulty. Check the ignition 
circuit.

SPARK PLUG TEST

M1163001500143

1. Remove the spark plug and connect to the ignition coil.

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.

SPARK PLUG CHECK AND CLEANING 

M1163004300397

CAUTION

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

the iridium 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: 1.2 mm (0.047 inch)

CAMSHAFT POSITION SENSOR CHECK

M1163004400208

<2.4L ENGINE>

Refer to GROUP 13A, Multiport Fuel Injection (MFI) <2.4L 
Engine> 

− Multiport Fuel Injection (MFI) Diagnosis − Diagnostic 

Trouble Code Procedures 

− DTC P0340 : Camshaft Position 

Sensor Circuit 

P.13A-566

.

AKX00432

SPARK PLUG

AB

AKX00277

DEFECTIVE INSULATION

DEFECTIVE INSULATION

DEFECTIVE
INSULATION

GOOD

AB

AKX00383

AKX00383

IRIDIUM TIP

AK